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49 results on '"Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR)"'

1. A Porphyrin Dimer–GdDOTA Conjugate as a Theranostic Agent for One- and Two-Photon Photodynamic Therapy and MRI

Author

Sébastien Jenni, Barbara Ventura, Célia S. Bonnet, Éva Tóth, Angélique Sour, Frédéric Bolze, Valérie Heitz, Agnès Pallier, Julie Schmitt, Institut de Chimie de Strasbourg, Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Conception et application de molécules bioactives (CAMB), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre de biophysique moléculaire (CBM), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), Consiglio Nazionale delle Ricerche (CNR), Université de Strasbourg (UNISTRA), ISOF-CNR, Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and LEGOUPIL, Laëtitia

Subjects
Porphyrins, [SDV]Life Sciences [q-bio], medicine.medical_treatment, MRI contrast agent, Dimer, Biomedical Engineering, Pharmaceutical Science, Bioengineering, Photodynamic therapy, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Theranostic Nanomedicine, HeLa, chemistry.chemical_compound, Nuclear magnetic resonance, Two-photon excitation microscopy, Heterocyclic Compounds, Theranostic agent, Neoplasms, Organometallic Compounds, medicine, Humans, [CHIM.COOR]Chemical Sciences/Coordination chemistry, ComputingMilieux_MISCELLANEOUS, Pharmacology, Photons, Photosensitizing Agents, Singlet Oxygen, biology, Singlet oxygen, Organic Chemistry, 021001 nanoscience & nanotechnology, biology.organism_classification, Magnetic Resonance Imaging, Porphyrin, 0104 chemical sciences, 3. Good health, [SDV] Life Sciences [q-bio], Photochemotherapy, chemistry, Porphyrin dimer, 0210 nano-technology, Dimerization, MRI, HeLa Cells, Biotechnology, Conjugate
Abstract

International audience; A molecular theranostic agent designed for photodynamic therapy (PDT) treatment in the near-infrared and for imaging tissue tumors with magnetic resonance imaging (MRI) is reported. It consists of a linear pi-conjugated Zn(II) porphyrin dimer linked at each extremity to a GdDOTA-type complex. This agent has shown very promising potential for PDT applications with good singlet oxygen generation in DMSO and high linear absorption in the near- infrared (lambda(max) = 746 nm, epsilon approximate to 10(5) M-1 cm(-1)). Moreover, this molecule has a propensity for two-photon excited PDT with high two-photon cross sections (similar to 8000 GM in 880-930 nm range), which should allow for deeper tumor treatments and higher spatial precision as compared to conventional one-photon PDT. Regarding the MRI contrast agent properties, the molecule has shown superior relaxivity (14.4 mM(-1) s(-1) at 40 MHz, 298 K) in comparison to clinical contrast agents and the ability to be internalized in cells, thanks to its amphiphilic character. Irradiation of HeLa cells using either one-photon (740 nm) or two-photon excitation (910 nm) has led in both cases to important cell death.

Published
2018
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2. Multiscale time-resolved fluorescence study of a glycogen phosphorylase inhibitor combined with quantum chemistry calculations

Author

Dimitra Markovitsi, Konstantinos F. Mavreas, Michael Mamais, Thanasis Gimisis, Filippo Monti, Evangelia D. Chrysina, Alessandro Venturini, Thomas Gustavsson, Valentin Maffeis, Laboratoire Innovation en Chimie des Surfaces et NanoSciences (LICSEN UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), National and Kapodistrian University of Athens (NKUA), Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Dynamique et Interactions en phase Condensée (DICO), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), National Hellenic Research Foundation [Athens], Istituto CNR per la Sintesi Organica e Fotoreattivita (ISOF), European Project: 284464,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2011-1,LASERLAB-EUROPE(2012), Laboratoire Innovation en Chimie des Surfaces et NanoSciences (LICSEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Consiglio Nazionale delle Ricerche (CNR), Biomolécules Excitées (DICO), and Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Inhibitor, Population, General Physics and Astronomy, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, DFT, Benzoates, Fluorescence spectroscopy, Glycogen phosphorylase, chemistry.chemical_compound, Computational chemistry, Physical and Theoretical Chemistry, Enzyme Inhibitors, education, Conformational isomerism, education.field_of_study, Chemistry, Glycogen Phosphorylase, 021001 nanoscience & nanotechnology, Fluorescence, Multiscale fluorescence, 3. Good health, 0104 chemical sciences, Acridone, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Spectrometry, Fluorescence, Excited state, Quantum Theory, Thermodynamics, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Time-resolved spectroscopy, 0210 nano-technology, Acridones
Abstract

International audience; A fluorescence study of N1-(β-D-glucopyranosyl)-N4-[2-acridin-9(10H)-onyl]-cytosine (GLAC), the first fluorescent potent inhibitor of glycogen phosphorylase (GP), in neutral aqueous solution, is presented herein. Quantum chemistry (TD-DFT) calculations show the existence of several conformers both in the ground and first excited states. They result from rotations of the acridone and cytosine moieties around an NH bridge which may lead to the formation of non-emitting charge-transfer states. The fingerprints of various conformers have been detected by time-resolved fluorescence spectroscopy (fluorescence upconversion and time-correlated single photon counting) and identified using as criteria their energy, polarization and relative population resulting from computations. Such an analysis should contribute to the design of new GP inhibitors with better fluorescence properties, suitable for imaging applications.

Published
2019
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3. Dinuclear Copper(I) Complexes Combining Bis(diphenylphosphanyl)acetylene with 1,10-Phenanthroline Ligands

Author

Michel Holler, Enrico Leoni, Filippo Monti, Alix Sournia-Saquet, Nicola Armaroli, Béatrice Delavaux-Nicot, Jean-François Nierengarten, Iwona Nierengarten, Laboratoire de chimie moléculaire (LCM), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratorio Tecnologie dei Materiali Faenza, ENEA, Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile (ENEA), Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), Consiglio Nazionale delle Ricerche (CNR), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile = Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), International Center for Frontier Research in Chemistry, LabEx 'Chimie des Systèmes Complexes', CNR (PHEEL), Nierengarten, J. -F., Nierengarten, I., Holler, M., Sournia-Saquet, A., Delavaux-Nicot, B., Leoni, E., Monti, F., and Armaroli, N.

Subjects
Luminescence, Dinuclear complexes, Phenanthroline, Substituent, chemistry.chemical_element, Phosphanes, 02 engineering and technology, Crystal structure, 010402 general chemistry, 01 natural sciences, Inorganic Chemistry, Neocuproine, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Homoleptic, Copper, 030304 developmental biology, 0303 health sciences, Ligand, Metallacycle, 021001 nanoscience & nanotechnology, 3. Good health, 0104 chemical sciences, Dinuclear complexe, Crystallography, chemistry, 030220 oncology & carcinogenesis, 0210 nano-technology
Abstract

Dinuclear copper(I) complexes have been prepared starting from bis(diphenylphosphanyl)acetylene (dppa), [Cu(CH3CN)(4)](BF4) and various 1,10-phenanthroline ligands (NN), namely 1,10-phenanthroline (phen), neocuproine (dmp), bathophenanthroline (Bphen), bathocuproine (Bdmp) and 2-phenyl-1,10-phenanthroline (mpp). The resulting [Cu-2(mu-dppa)(2)(NN)(2)](BF4)(2) complexes have been thus obtained in excellent yields (88 to 94 %). X-ray crystal structure analysis of four complexes revealed that the 10-membered dimetallacycle adopts a chair-like conformation in the solid state. Detailed variable temperature NMR investigations have evidenced dynamic coordination/decoordination of the NN ligands as well as ligand exchange reactions. At high temperature (100 degrees C), entropic effects tend to destabilize the dinuclear heteroleptic complexes. As a result, homoleptic mononuclear complexes, i.e. [Cu(NN)(2)](+) and undefined dppa copper(I) complexes, start to appear in solution. In contrast, the heteroleptic coordination scenario is almost exclusively favored at lower temperatures. For most of the dinuclear complexes, the 10-membered dimetallacycle remains flexible and chair-to-chair interconversion occurs faster than the NMR timescale even at -70 degrees C. In the particular case of the mpp derivative, the bulky phenyl substituent prevents the isomerization of the metallacycle and thus contributes to rigidify the structure. This rigidification has a dramatic effect on the emission properties of this particular compound. The emission quantum yield of [Cu-2(mu-dppa)(2)(mpp)(2)](BF4)(2) is effectively one order of magnitude higher when compared to all the other complexes in this series (20 % vs. 0.3-1.7 % in the solid state).

Published
2019
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4. Cyclometalated N-heterocyclic carbene iridium( iii ) complexes with naphthalimide chromophores: a novel class of phosphorescent heteroleptic compounds

Author

Hani Amouri, Geoffrey Gontard, Antoine Groué, Pierre-Henri Lanoë, Filippo Monti, Marie-Noëlle Rager, Nicola Armaroli, Andrea Barbieri, Jonny Chan, Anny Jutand, Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut Parisien de Chimie Moléculaire (IPCM), Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Chimie Moléculaire de Paris Centre (FR 2769), Institut de Chimie du CNRS (INC)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Processus d'Activation Sélective par Transfert d'Energie Uni-électronique ou Radiatif (UMR 8640) (PASTEUR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Service de Résonance Magnétique Nucléaire, Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), Consiglio Nazionale delle Ricerche (CNR), Gulliver (UMR 7083), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), IRPPS-CNR, Salerno, and Università degli Studi di Salerno (UNISA)

Subjects
Iridium complexes, Denticity, Phosphorescence, 010405 organic chemistry, Ligand, chemistry.chemical_element, Nuclear magnetic resonance spectroscopy, Chromophore, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, Inorganic Chemistry, chemistry.chemical_compound, chemistry, Polymer chemistry, Imidazole, Moiety, Iridium, Carbene, ComputingMilieux_MISCELLANEOUS
Abstract

A series of cyclometalated N-heterocyclic carbene complexes of the general formula [Ir(CN)(2)(CC:)] has been prepared. Two sets of compounds were designed, those where (CC:) represents a bidentate naphthalimide-substituted imidazolylidene ligand and (CN) = ppy (3a), F2ppy (4a), bzq (5a) and those where (CC:) represents a naphthalimide-substituted benzimidazolylidene ligand and (CN) = ppy (3b), F2ppy (4b), bzq (5b). The naphthalimide-imidazole and naphthalimide-benzimidazole ligands 1a,b and the related imidazolium and benzimidazolium salts 2a, b were also prepared and fully characterized. The N-heterocyclic carbene Ir(III) complexes have been characterized by NMR spectroscopy, cyclic voltammetry and elemental analysis. Moreover, the molecular structures of one imidazolium salt and four Ir(III) complexes were determined by single-crystal X-ray diffraction. The structures provide us with valuable information, most notably the orientation of the naphthalimide chromophore with respect to the N-heterocyclic carbene moiety. All compounds are luminescent at room temperature and in a frozen solvent at 77 K, exhibiting a broad emission band that extends beyond 700 nm. The presence of the naphthalimide moiety changes the character of the lowest excited state from (MLCT)-M-3 to (LC)-L-3, as corroborated by DFT and TD-DFT calculations. Remarkably, replacing imidazole with a benzimidazole unit improves the quantum yields of these compounds by decreasing the k(nr) values which is an important feature for optimized emission performance. These studies provide valuable insights about a novel class of N-heterocyclic carbene-based luminescent complexes containing organic chromophores and affording metal complexes emitting across the red-NIR range.

Published
2018
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5. Heteroleptic Copper(I) Complexes Prepared from Phenanthroline and Bis-Phosphine Ligands: Rationalization of the Photophysical and Electrochemical Properties

Author

John Mohanraj, Meera Mohankumar, Iwona Nierengarten, Michel Holler, Béatrice Delavaux-Nicot, Alix Sournia-Saquet, Jean-François Nierengarten, Nicola Armaroli, Filippo Monti, Enrico Leoni, Leoni, E., Mohanraj, J., Holler, M., Mohankumar, M., Nierengarten, I., Monti, F., Sournia-Saquet, A., Delavaux-Nicot, B., Jean-Francois, Nierengarten, Armaroli, N., Leoni, Enrico, Mohanraj, John, Holler, Michel, Mohankumar, Meera, Nierengarten, Iwona, Monti, Filippo, Sournia-Saquet, Alix, Delavaux-Nicot, Béatrice, Jean-Francois Nierengarten, null, Armaroli, Nicola, Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), Consiglio Nazionale delle Ricerche (CNR), Laboratoire de chimie moléculaire (LCM), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Cu(I) complexes, Luminescence, Absorption spectroscopy, 010405 organic chemistry, Phenanthroline, Excited states, chemistry.chemical_element, Ether, Crystal structure, 010402 general chemistry, Electrochemistry, 01 natural sciences, Medicinal chemistry, Copper, 0104 chemical sciences, 3. Good health, Inorganic Chemistry, chemistry.chemical_compound, chemistry, Density functional theory, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Physical and Theoretical Chemistry, Phosphine
Abstract

The electronic and structural properties of ten heteroleptic [Cu(NN)(PP)]+ complexes have been investigated. NN indicates 1,10-phenanthroline (phen) or 4,7-diphenyl-1,10-phenanthroline (Bphen); each of these ligands is combined with five PP bis-phosphine chelators, i.e., bis(diphenylphosphino)methane (dppm), 1,2-bis(diphenylphosphino)ethane (dppe), 1,3-bis(diphenylphosphino)propane (dppp), 1,2-bis(diphenylphosphino)benzene (dppb), and bis[(2-diphenylphosphino)phenyl] ether (POP). All complexes are mononuclear, apart from those based on dppm, which are dinuclear. Experimental data - also taken from the literature and including electrochemical properties, X-ray crystal structures, UV-vis absorption spectra in CH2Cl2, luminescence spectra and lifetimes in solution, in PMMA, and as powders - have been rationalized with the support of density functional theory calculations. Temperature dependent studies (78-358 K) have been performed for selected complexes to assess thermally activated delayed fluorescence. The main findings are (i) dependence of the ground-state geometry on the crystallization conditions, with the same complex often yielding different crystal structures; (ii) simple model compounds with imposed C2v symmetry ([Cu(phen)(PX3)2]+ X = H or CH3) are capable of modeling structural parameters as a function of the P-Cu-P bite angle, which plays a key role in dictating the overall structure of [Cu(NN)(PP)]+ complexes; (iii) as the P-Cu-P angle increases, the energy of the metal-to-ligand charge transfer absorption bands linearly increases; (iv) the former correlation does not hold for emission spectra, which are red-shifted for the weaker luminophores; (v) the larger the number of intramolecular π-interactions within the complex in the ground state, the higher the luminescence quantum yield, underpinning a geometry locking effect that limits the structural flattening of the excited state. This work provides a general framework to rationalize the structure-property relationships of [Cu(NN)(PP)]+, a class of compounds of increasing relevance for electroluminescent devices, photoredox catalysis, and solar-to-fuels conversion, which so far have been investigated in an unsystematic fashion, eluding a comprehensive understanding. © Copyright 2018 American Chemical Society.

Published
2018
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6. Heteroleptic copper(I) pseudorotaxanes incorporating macrocyclic phenanthroline ligands of different sizes

Author

Nicola Armaroli, Joanna M. Malicka, Meera Mohankumar, Jean-Pierre Sauvage, Michel Holler, Béatrice Delavaux-Nicot, Elisa Bandini, Eric Meichsner, Massimo Cocchi, Jean-François Nierengarten, Enrico Leoni, Filippo Monti, Frédéric Niess, Laboratoire de chimie moléculaire (LCM), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Science et d'ingénierie supramoléculaires (ISIS), Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), Consiglio Nazionale delle Ricerche (CNR), Laboratorio Tecnologie dei Materiali Faenza, ENEA, Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile (ENEA), Laboratory for Micro and Submicro Enabling Technologies of the Emilia-Romagna Region (MIST E-R), Università degli Studi di Ferrara (UniFE), Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche [Roma] (CNR), Mohankumar, Meera, Holler, Michel, Meichsner, Eric, Nierengarten, Jean-François, Niess, Frédéric, Sauvage, Jean-Pierre, Delavaux-Nicot, Béatrice, Leoni, Enrico, Monti, Filippo, Malicka, Joanna M., Cocchi, Massimo, Bandini, Elisa, Armaroli, Nicola, Mohankumar, M., Holler, M., Meichsner, E., Nierengarten, J. -F., Niess, F., Sauvage, J. -P., Delavaux-Nicot, B., Leoni, E., Monti, F., Malicka, J. M., Cocchi, M., Bandini, E., and Armaroli, N.

Subjects
Photoluminescence, oled, Rotaxanes, Phenanthroline, chemistry.chemical_element, Ether, 010402 general chemistry, 01 natural sciences, Biochemistry, Catalysis, Catalysi, chemistry.chemical_compound, Colloid and Surface Chemistry, luminescence, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Methyl methacrylate, Cu(I) complexes, 010405 organic chemistry, Chemistry (all), General Chemistry, Copper, 0104 chemical sciences, 3. Good health, Crystallography, chemistry, Macrocyclic ligand, Absorption (chemistry), Luminescence
Abstract

International audience; A series of copper(I) pseudorotaxanes has been prepared from bis[2-(diphenylphosphino)phenyl] ether (POP) and macrocyclic phenanthroline ligands with different ring sizes (m30, m37, and m42). Variable-temperature studies carried out on the resulting [Cu(mXX)(POP)]+ (mXX = m30, m37, and m42) derivatives have revealed a dynamic conformational equilibrium due to the folding of the macrocyclic ligand. The absorption and luminescence properties of the pseudorotaxanes have been investigated in CH2Cl2. They exhibit metal-to-ligand charge-transfer emission with photoluminescence quantum yields (PLQYs) in the range 20–30%. The smallest system [Cu(m30)(POP)]+ shows minimal differences in spectral shape and position compared to its analogues, suggesting a slightly distorted coordination environment. PLQY is substantially enhanced in poly(methyl methacrylate) films (∼40−45%). The study of emission spectra and excited-state lifetimes in powder samples as a function of temperature (78–338 K) reveals thermally activated delayed fluorescence, with sizable differences in the singlet–triplet energy gap compared to the reference compound [Cu(dmp)(POP)]+ (dmp = 2,9-dimethyl-1,10-phenanthroline) and within the pseudorotaxane series. The system with the largest ring ([Cu(m42)(POP)]+) has been tested as emissive material in OLEDs and affords bright green devices with higher luminance and greater stability compared to [Cu(dmp)(POP)]+, which lacks the macrocyclic ring. This highlights the importance of structural factors in the stability of electroluminescent devices based on Cu(I) materials.

Published
2018
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7. Efficient Photoinduced Energy and Electron Transfer in Zn II -Porphyrin/Fullerene Dyads with Interchromophoric Distances up to 2.6 nm and No Wire-like Connectivity

Author

John Mohanraj, Nicola Armaroli, Jean-François Nierengarten, Uwe Hahn, Béatrice Delavaux-Nicot, Julien Iehl, Maida Vartanian, Fernando Langa, María Vizuete, Andrea Barbieri, Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), Consiglio Nazionale delle Ricerche (CNR), IRPPS-CNR, Salerno, Università degli Studi di Salerno (UNISA), Instituto de Nanociencia, Nanotecnología y Materiales Moleculares (INAMOL), Universidad de Castilla-La Mancha (UCLM), Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie des Matériaux Moléculaires, Laboratoire d'innovation moléculaire et applications (LIMA), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), and Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS)

Subjects
Fullerene, Luminescence, Quantum yield, Porphyrinoids, Conjugated system, 010402 general chemistry, Photochemistry, 01 natural sciences, 7. Clean energy, Catalysis, Photoinduced electron transfer, Electron transfer, chemistry.chemical_compound, [CHIM]Chemical Sciences, 010405 organic chemistry, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Organic Chemistry, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, Chromophore, Porphyrin, 0104 chemical sciences, Benzonitrile, chemistry, Energy transfer, Fullerenes
Abstract

International audience; The dyads 1–3 made of an alkynylated ZnII–porphyrin and a bis‐methanofullerene derivative connected through a copper‐catalyzed azide–alkyne cycloaddition have been synthesized. The porphyrin and fullerene chromophores are separated through a bridge made of a bismethanofullerene tether linked to different spacers conjugated to the porphyrin moiety [i.e., m‐phenylene (1), p‐phenylene (2), di‐p‐phenylene‐ethynylene (3)]. Compounds 1–3 exhibit relatively rigid structures with an interchromophoric separation of 1.7, 2.0, and 2.6 nm, respectively, and no face‐to‐face or direct through‐bond conjugation. The photophysical properties of compounds 1–3 have been investigated in toluene and benzonitrile with steady‐state and time‐resolved techniques as well as model calculations on the Förster energy transfer. Excited‐state interchromophoric electronic interactions are observed with a distinct solvent and distance dependence. The latter effect is evidenced in benzonitrile, where compounds 1 and 2 exhibit a photoinduced electron transfer in the Marcus‐inverted region, with charge‐separated (CS) states living for 0.44 and 0.59 μs, respectively, whereas compound 3 only undergoes energy transfer, as in apolar toluene. The quantum yield of the charge separation (φCS) of compounds 1 and 2 in benzonitrile is ≥0.75. It is therefore demonstrated that photoinduced energy and electron transfers in porphyrin–fullerene systems with long interchromophoric distances may efficiently occur also when the bridge does not provide a wire‐like conjugation and proceed through the triplet states of the chromophoric moieties.

Published
2017
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8. Ester-substituted cyclometallated rhodium and iridium coordination assemblies with π-bonded dioxolene ligand: synthesis, structures and luminescent properties

Author

Maria Pia Gullo, Hugo Sesolis, Marie Noelle Rager, Hani Amouri, Andrea Barbieri, Aurélie Damas, Lise Marie Chamoreau, Institut Parisien de Chimie Moléculaire (IPCM), Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC), Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), Consiglio Nazionale delle Ricerche (CNR), Architectures Moléculaires (A.R.C), Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Chemistry, Ligand, General Chemical Engineering, Supramolecular chemistry, Stacking, chemistry.chemical_element, General Chemistry, Photochemistry, 3. Good health, Rhodium, Excited state, Polymer chemistry, [CHIM]Chemical Sciences, Iridium, Luminescence, ComputingMilieux_MISCELLANEOUS
Abstract

A series of functionalized cyclometallated rhodium and iridium coordination assemblies 2-7 displaying a pi-bonded dioxolene ligand is described. The X-ray molecular structures of two of the above compounds showed the formation of a 1D supramolecular chain mediated by pi-pi interactions among individual units. The luminescent properties of these compounds are presented and discussed. These results show that the stacking interactions are retained also in solution and emission from excited dimeric species is observed.

Published
2014
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9. A New Potent Inhibitor of Glycogen Phosphorylase Reveals the Basicity of the Catalytic Site

Author

Filippo Monti, Dimitra Markovitsi, Alessandra Degli Esposti, Evangelia D. Chrysina, Alessandro Venturini, Virginia Kouloumoundra, Thomas Gustavsson, Thanasis Gimisis, Michael Mamais, National and Kapodistrian University of Athens (NKUA), Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), Consiglio Nazionale delle Ricerche (CNR), Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Biomolécules Excitées (DICO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Gulliver (UMR 7083), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), National Hellenic Research Foundation [Athens], National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Dynamique et Interactions en phase Condensée (DICO), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)

Subjects
0301 basic medicine, Absorption spectroscopy, Stereochemistry, Static Electricity, 010402 general chemistry, Crystallography, X-Ray, 01 natural sciences, Catalysis, 03 medical and health sciences, Glycogen phosphorylase, chemistry.chemical_compound, Catalytic Domain, Fluorescent protein, Enzyme Inhibitors, Potent Inhibitor, chemistry.chemical_classification, Binding Sites, GLAC, Organic Chemistry, Glycogen Phosphorylase, Hydrogen Bonding, General Chemistry, Optical spectra, 0104 chemical sciences, 3. Good health, Acridone, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, 030104 developmental biology, Enzyme, Glucose, chemistry, ddc:540, Quantum Theory, acridone derivative, Derivative (chemistry), Acridones
Abstract

International audience; The design and synthesis of a glucose-based acridone derivative (GLAC), a potent inhibitor of glycogen phosphorylase (GP) are described. GLAC is the first inhibitor of glycogen phosphorylase, the electronic absorption properties of which are clearly distinguishable from those of the enzyme. This allows probing subtle interactions in the catalytic site. The GLAC absorption spectra, associated with X-ray crystallography and quantum chemistry calculations, reveal that part of the catalytic site of GP behaves as a highly basic environment in which GLAC exists as a bis-anion. This is explained by water-bridged hydrogen-bonding interactions with specific catalytic site residues.

Published
2017
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10. Luminescent Cyclometalated Platinum Complexes with π-Bonded Catecholate Organometallic Ligands

Author

Hani Amouri, Elisa Bandini, Alessandra Degli Esposti, Jamal Moussa, Aruny Loch, Lise-Marie Chamoreau, Andrea Barbieri, Institut Parisien de Chimie Moléculaire (IPCM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), Consiglio Nazionale delle Ricerche (CNR), Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), and National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)

Subjects
010405 organic chemistry, Chemistry, Solid-state, chemistry.chemical_element, 010402 general chemistry, Photochemistry, 01 natural sciences, 0104 chemical sciences, Supramolecular assembly, Inorganic Chemistry, Crystallography, [CHIM]Chemical Sciences, Density functional theory, Catecholate Organometallic Ligands, Physical and Theoretical Chemistry, Platinum, Luminescence, Cyclometalated Platinum Complexes
Abstract

A series of cyclometalated platinum(II) complexes of the type [(ppy)Pt(LM)]n+ (n = 0, 1) with ?-bonded catecholates acting as organometallic ligands (LM) have been prepared and characterized by analytical techniques. In addition, the structures of two complexes of the series were determined by single-crystal X-ray diffraction. The packing shows the formation of a 1D supramolecular assembly generated by dPt-?Cp* interactions among individual units. All complexes are luminescent in the solid state and in solution media. The results of photophysics have been rationalized by means of density functional theory (DFT) and time-dependent DFT investigations.A series of cyclometalated platinum(II) complexes of the type [(ppy)Pt(LM)]n+ (n = 0, 1) with ?-bonded catecholates acting as organometallic ligands (LM) have been prepared and characterized by analytical techniques. In addition, the structures of two complexes of the series were determined by single-crystal X-ray diffraction. The packing shows the formation of a 1D supramolecular assembly generated by dPt-?Cp* interactions among individual units. All complexes are luminescent in the solid state and in solution media. The results of photophysics have been rationalized by means of density functional theory (DFT) and time-dependent DFT investigations.

Published
2017
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11. Four Gadolinium(III) Complexes Appended to a Porphyrin: A Water-Soluble Molecular Theranostic Agent with Remarkable Relaxivity Suited for MRI Tracking of the Photosensitizer

Author

Célia S. Bonnet, Barbara Ventura, Paulo Loureiro de Sousa, Angélique Sour, Valérie Heitz, Ana Ortí-Suárez, Sébastien Jenni, Éva Tóth, Chrystelle Po, Agnès Pallier, Julie Schmitt, Frédéric Bolze, Université de Strasbourg (UNISTRA), Laboratoire des sciences de l'ingénieur, de l'informatique et de l'imagerie (ICube), Institut National des Sciences Appliquées - Strasbourg (INSA Strasbourg), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de Strasbourg, Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Conception et application de molécules bioactives (CAMB), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Biologique, Centre National de la Recherche Scientifique (CNRS), Centre de biophysique moléculaire (CBM), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), Consiglio Nazionale delle Ricerche (CNR), École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Université de Strasbourg (UNISTRA)-Institut National des Sciences Appliquées - Strasbourg (INSA Strasbourg), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Les Hôpitaux Universitaires de Strasbourg (HUS)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, and Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Porphyrins, Light, MRI contrast agent, medicine.medical_treatment, Gadolinium, Proton Magnetic Resonance Spectroscopy, [SDV]Life Sciences [q-bio], chemistry.chemical_element, Photodynamic therapy, 010402 general chemistry, 01 natural sciences, Theranostic Nanomedicine, Inorganic Chemistry, chemistry.chemical_compound, Nuclear magnetic resonance, Coordination Complexes, medicine, Humans, Photosensitizer, Yttrium, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Physical and Theoretical Chemistry, ComputingMilieux_MISCELLANEOUS, Photosensitizing Agents, Cell Death, 010405 organic chemistry, Singlet oxygen, HIGH MAGNETIC-FIELD, CONTRAST AGENTS, PHOTODYNAMIC THERAPY, CANCER-THERAPY, DRUG-DELIVERY, BRAIN-TUMORS, NANOPARTICLES, RESONANCE, NANOMEDICINE, DESIGN, Water, Porphyrin, Magnetic Resonance Imaging, 0104 chemical sciences, chemistry, Solubility, Chimie/Chimie inorganique, Phototoxicity, Lysosomes, Conjugate, HeLa Cells
Abstract

A molecular theranostic agent for magnetic resonance imaging (MRI) and photodynamic therapy (PDT) consisting of four [GdDTTA](-) complexes (DTTA(4-) = diethylenetriamine-N,N,N",N"-tetraacetate) linked to a meso-tetraphenylporphyrin core, as well as its yttrium(III) analogue, was synthesized. A variety of physicochemical methods were used to characterize the gadolinium(III) conjugate 1 both as an MRI contrast agent and as a photosensitizer. The proton relaxivity measured in H2O at 20 MHz and 25 degrees C, r(1) = 43.7 mmol(-1) s(-1) per gadolinium center, is the highest reported for a bishydrated gadolinium(III)-based contrast agent of medium size and can be related to the rigidity of the molecule. The complex displays also a remarkable singlet oxygen quantum yield of phi(Delta) = 0.45 in H2O, similar to that of a meso-tetrasulfonated porphyrin. We also evidenced the ability of the gadolinium(III) conjugate to penetrate in cancer cells with low cytotoxicity. Its phototoxicity on Hela cells was evaluated following incubation at low micromolar concentration and moderate light irradiation (21 J cm(-2)) induced 50% of cell death. Altogether, these results demonstrate the high potential of this conjugate as a theranostic agent for MRI and PDT.

Published
2016
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12. Deep-Red Phosphorescent Iridium(III) Complexes with Chromophoric N-Heterocyclic Carbene Ligands: Design, Photophysical Properties, and DFT Calculations

Author

Nicola Armaroli, Pierre-Henri Lanoë, Geoffrey Gontard, Hani Amouri, Jonny Chan, Andrea Barbieri, Filippo Monti, Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut Parisien de Chimie Moléculaire (IPCM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Chimie Moléculaire de Paris Centre (FR 2769), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Gulliver (UMR 7083), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), IRPPS-CNR, Salerno, Università degli Studi di Salerno = University of Salerno (UNISA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Consiglio Nazionale delle Ricerche (CNR), and Università degli Studi di Salerno (UNISA)

Subjects
Luminescence, 010405 organic chemistry, Ligand, chemistry.chemical_element, Chromophore, Iridium, 010402 general chemistry, Photochemistry, 01 natural sciences, 0104 chemical sciences, Inorganic Chemistry, chemistry.chemical_compound, Charge transfer, Photophysics, chemistry, Excited state, Moiety, [CHIM]Chemical Sciences, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Phosphorescence, Carbene ligands, Carbene, ComputingMilieux_MISCELLANEOUS
Abstract

The synthesis of three deep-red-emitting iridium(III) complexes featuring a naphthalimide N-heterocyclic carbene ligand was investigated. The introduction of this organic chromophore onto the carbene moiety changed the character of the lowest excited state from triplet metal-to-ligand charge transfer to triplet ligand centered, as corroborated by time-dependent DFT calculations. All complexes displayed a naphthalimide- based deep-red phosphorescence emission above lambda = 630 nm in polymer matrix with good quantum yields (Phi approximate to 0.2) and long lifetimes.

Published
2016
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13. Deep-Red Phosphorescent Iridium(III) Complexes with Chromophoric N-Heterocyclic Carbene Ligands: Design, Photophysical Properties, and DFT Calculations (Eur. J. Inorg. Chem. 11/2016)

Author

Pierre-Henri Lanoë, Geoffrey Gontard, Filippo Monti, Andrea Barbieri, Jonny Chan, Hani Amouri, Nicola Armaroli, Architectures Moléculaires (A.R.C), Institut Parisien de Chimie Moléculaire (IPCM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), and Consiglio Nazionale delle Ricerche (CNR)

Subjects
010405 organic chemistry, Chemistry, chemistry.chemical_element, 010402 general chemistry, Photochemistry, 01 natural sciences, 0104 chemical sciences, Inorganic Chemistry, chemistry.chemical_compound, [CHIM]Chemical Sciences, Iridium, Phosphorescence, Luminescence, Carbene, ComputingMilieux_MISCELLANEOUS
Abstract

International audience; no abstract

Published
2016
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14. Synthesis and Photophysical Properties of Copper(I) Complexes Obtained from 1,10‐Phenanthroline Ligands with Increasingly Bulky 2,9‐Substituents

Author

Alix Saquet, Carine Duhayon, Michel Holler, Omar Moudam, Nicola Armaroli, Gianluca Accorsi, Richard Welter, Béatrice Delavaux-Nicot, Jean-François Nierengarten, Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), Consiglio Nazionale delle Ricerche (CNR), Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Louis Pasteur - Laboratoire Decomet (UMR 7177-LC3), Université Louis Pasteur - Strasbourg I-Commencez à saisir le nom d'une tutelle, and Ecole nationale supérieure de chimie, polymères et materiaux de strasbourg (ECPM)

Subjects
Electronic structure, Luminescence, Absorption spectroscopy, Phenanthroline, chemistry.chemical_element, 010402 general chemistry, Electrochemistry, Photochemistry, 01 natural sciences, Inorganic Chemistry, chemistry.chemical_compound, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Quenching (fluorescence), 010405 organic chemistry, Copper, 0104 chemical sciences, 3. Good health, Crystallography, chemistry, Ground state
Abstract

In this paper, we describe the synthesis and the electronic properties of a series of [Cu(NN) 2 ] + systems. The NN ligands investigated are 2,9-bis[(tert-butyldimethylsilyloxy)methyl]-1,10-phenanthroline (1), 2,9-bis[(triisopropylsilyloxy)methyl]-1,10-phenanthroline (2), 2,9-bis[(tert-butyldiphenylsilyl-moxy)ethyl]-1,10-phenanthroline (3), 2,9-bis[2,6-bis(benzyl-oxy)phenethyl]-1,10-phenanthroline (4) and 2-(1,3-diphenylpropan-2-yl)-9-phenethyl-1,10-phenanthroline (5). The electrochemical properties and the ground state electronic absorption spectra of Cu(1) 2 ―Cu(5) 2 are in line with the classical behaviour of such [Cu(NN) 2 ] + derivatives. Whereas all the compounds exhibit MLCT luminescence centered around 630―650 nm, the emission quantum yields and the lifetimes are dramatically different as a function of stereo-electronic effects and/or the possibility of internal exciplex quenching when oxygen-containing functional groups are attached to the phenanthroline ligands.

Published
2009
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15. Induced phosphorescence from Pt → Ag and Ag( \textlessspan style='font-variant:small-caps;'\textgreateri\textless/span\textgreater )⋯Ag( \textlessspan style='font-variant:small-caps;'\textgreateri\textless/span\textgreater ) metallophilic interactions in benzenedithiolatodiimine-Pt _\textrm2 /Ag _\textrm2 clusters: a combined experimental and theoretical investigation

Author

Moussa, Jamal, Chamoreau, Lise Marie, Gullo, Maria Pia, Degli Esposti, Alessandra, Barbieri, Andrea, Amouri, Hani, Architectures Moléculaires (A.R.C), Institut Parisien de Chimie Moléculaire (IPCM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), and Consiglio Nazionale delle Ricerche (CNR)

Subjects
[CHIM]Chemical Sciences, ComputingMilieux_MISCELLANEOUS
Abstract

International audience; no abstract

Published
2016
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16. A unique class of neutral cyclometalated platinum( \textlessspan style='font-variant:small-caps;'\textgreaterii\textless/span\textgreater ) complexes with π-bonded benzenedithiolate: synthesis, molecular structures and tuning of luminescence properties

Author

Sesolis, Hugo, Moussa, Jamal, Gontard, Geoffrey, Jutand, Anny, Gullo, Maria Pia, Barbieri, Andrea, Amouri, Hani, Institut Parisien de Chimie Moléculaire (IPCM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Architectures Moléculaires (A.R.C), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Processus d'Activation Sélective par Transfert d'Energie Uni-électronique ou Radiatif (UMR 8640) (PASTEUR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), and Consiglio Nazionale delle Ricerche (CNR)

Subjects
[CHIM]Chemical Sciences, ComputingMilieux_MISCELLANEOUS
Abstract

International audience; no abstract

Published
2015
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17. International benchmark on the natural convection test in Phenix reactor

Author

Hiroyasu Mochizuki, Aurélia Chenu, Y. Shvetsov, L. Maas, T. H. Fanning, Stefano Monti, D. Pialla, H.-Y. Jeong, J. W. Thomas, Konstantin Mikityuk, D. Tenchine, P. Chellapandi, Service de Thermo-hydraulique et de Mécanique des Fluides (STMF), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Argonne National Laboratory [Lemont] (ANL), Nuclear and Radioanalytical Chemistry, IGCAR, Kalpakkam-603102, Tamilnadu, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Korea Atomic Energy Research Institute [Daejeon, south Korea] (KAERI), Paul Scherrer Institute (PSI), University of Fukui [Bunkyo], Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), International Atomic Energy Agency [Vienna] (IAEA), and Consiglio Nazionale delle Ricerche (CNR)

Subjects
Nuclear and High Energy Physics, Engineering, Russian federation, Sensitivity studies, 020209 energy, Shutdown, Nuclear engineering, Control rod, Testing, Mechanical engineering, 02 engineering and technology, Scram, 01 natural sciences, 7. Clean energy, 010305 fluids & plasmas, Blind calculations, Sodium-cooled fast reactor, Benchmark (surveying), 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, General Materials Science, Natural circulation, Safety, Risk, Reliability and Quality, Waste Management and Disposal, Sodium cooled fast reactors (SFR), [PHYS]Physics [physics], Natural convection, business.industry, Mechanical Engineering, Sodium, Test (assessment), Fast reactors, Nuclear Energy and Engineering, Primary circuits, 13. Climate action, business, Coordinated research projects, International atomic energy agency
Abstract

The French Phenix sodium cooled fast reactor (SFR) started operation in 1973 and was stopped in 2009. Before the reactor was definitively shutdown, several final tests were planned and performed, including a natural convection test in the primary circuit. During this natural convection test, the heat rejection provided by the steam generators was disabled, followed several minutes later by reactor scram and coast-down of the primary pumps. The International Atomic Energy Agency (IAEA) launched a Coordinated Research Project (CRP) named "control rod withdrawal and sodium natural circulation tests performed during the Phenix end-of-life experiments". The overall purpose of the CRP was to improve the Member States' analytical capabilities in the field of SFR safety. An international benchmark on the natural convection test was organized with "blind" calculations in a first step, then "post-test" calculations and sensitivity studies compared with reactor measurements. Eight organizations from seven Member States took part in the benchmark: ANL (USA), CEA (France), IGCAR (India), IPPE (Russian Federation), IRSN (France), KAERI (Korea), PSI (Switzerland) and University of Fukui (Japan). Each organization performed computations and contributed to the analysis and global recommendations. This paper summarizes the findings of the CRP benchmark exercise associated with the Phenix natural convection test, including blind calculations, post-test calculations and comparisons with measured data. General comments and recommendations are pointed out to improve future simulations of natural convection in SFRs. © 2013 Elsevier B.V.

Published
2013
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18. Unravelling molecular mechanisms in the fluorescence spectra of doxorubicin in aqueous solution by femtosecond fluorescence spectroscopy

Author

Pascale Changenet-Barret, Dimitra Markovitsi, Thomas Gustavsson, Ilse Manet, Sandra Monti, Laboratoire Francis PERRIN (LFP - URA 2453), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), Consiglio Nazionale delle Ricerche (CNR), and National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)

Subjects
Time Factors, Dimer, General Physics and Astronomy, Quantum yield, 02 engineering and technology, 010402 general chemistry, Photochemistry, 01 natural sciences, Fluorescence spectroscopy, NUCLEAR-MAGNETIC-RESONANCE, POLAR SOLVATION DYNAMICS, DNA TOPOISOMERASE-II, SELF-ASSOCIATION, DRUG-DELIVERY, ANTHRACYCLINE ACTIVITY, CIRCULAR-DICHROISM, CHARGE SEPARATION, UP-CONVERSION, BINDING, chemistry.chemical_compound, Physical and Theoretical Chemistry, Photons, Chemistry, Lasers, Water, 021001 nanoscience & nanotechnology, Internal conversion (chemistry), Fluorescence, 3. Good health, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Spectrometry, Fluorescence, Resonance fluorescence, Doxorubicin, Femtosecond, 0210 nano-technology, Dimerization, Fluorescence anisotropy
Abstract

International audience; Doxorubicin (DOX) is a potent anti-tumoral agent widely used for cancer therapy. Despite numerous studies, the fluorescence properties of DOX, usually exploited for the characterization of the interaction with biological media, have until now led to controversial interpretations, mainly due to self-association of the drug in aqueous solution. We present here the first femtosecond study of DOX based on measurements with the fluorescence up-conversion technique in combination with time-correlated single photon counting using the same laser source. We provide evidence that fluorescence signals of DOX stem from monomers and dimers. DOX dimerization induces a dramatic decrease in the fluorescence quantum yield from 3.9 × 10−2 to 10−5 associated with the red shift of the fluorescence spectrum by [similar]25 nm. While the fluorescence lifetime of the monomer is 1 ns, the dimer fluorescence is found to decay with a lifetime of about 2 ps. In contrast to monomers, the fluorescence anisotropy of dimers is found to be negative. These experimental observations are consistent with an ultrafast internal conversion (

Published
2013
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19. Near-Infrared Room Temperature Emission from a Novel Class of Ru(II) Heteroleptic Complexes with Quinonoid Organometallic Linker

Author

Marie Noelle Rager, Hani Amouri, Anny Jutand, Andrea Barbieri, Aurélie Damas, Maria Pia Gullo, Institut Parisien de Chimie Moléculaire (IPCM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL), Processus d'Activation Sélective par Transfert d'Energie Uni-électronique ou Radiatif (UMR 8640) (PASTEUR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Département de Chimie - ENS Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Architectures Moléculaires (A.R.C), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Consiglio Nazionale delle Ricerche (CNR), École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris)

Subjects
Inorganic chemistry, design, transition-metal-complexes, chemistry.chemical_element, polypyridine complexes, 010402 general chemistry, Ligands, 01 natural sciences, 7. Clean energy, Catalysis, Ruthenium, octahedral bimetallic assemblies, Coordination Complexes, Materials Chemistry, Organometallic Compounds, [CHIM]Chemical Sciences, photophysical properties, absorption-spectra, electrochemical-behavior, Spectroscopy, Near-Infrared, luminescence properties, 010405 organic chemistry, Ligand, Near-infrared spectroscopy, Metals and Alloys, Quinones, Temperature, General Chemistry, ray molecular-structure, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Crystallography, Octahedron, chemistry, Ceramics and Composites, Electronics, Luminescence, Linker, Oxidation-Reduction
Abstract

WOS:000317352600022; A novel class of luminescent octahedral ruthenium complexes 2-4 displaying a pi-bonded quinonoid ligand is described. Remarkably, the presence of this organometallic ligand affects their UV-vis properties and transforms them into panchromatic absorbers. Furthermore, it turns on room temperature NIR emissions.

Published
2013
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20. Turning on Red and Near-Infrared Phosphorescence in Octahedral Complexes with Metalated Quinones

Author

Aurélie Damas, Barbara Ventura, Hani Amouri, Alessandra Degli Esposti, Andrea Barbieri, Lise-Marie Chamoreau, Jamal Moussa, Institut Parisien de Chimie Moléculaire (IPCM), Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), Consiglio Nazionale delle Ricerche (CNR), Architectures Moléculaires (A.R.C), Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Viale dell'Università, Glycochimie Organique Biologique et Supramoléculaire (GOBS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010405 organic chemistry, Stereochemistry, chemistry.chemical_element, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, 0104 chemical sciences, Rhodium, Ruthenium, Inorganic Chemistry, chemistry.chemical_compound, TRISPHAT, chemistry, Octahedron, Luminophore, [CHIM]Chemical Sciences, Iridium, Physical and Theoretical Chemistry, DENSITY-FUNCTIONAL THEORY, SUPRAMOLECULAR TRIANGULAR HOSTS, MEDIATED ASYMMETRIC CHEMISTRY, EXCITED-STATE PROPERTIES, COORDINATION-COMPOUNDS, CYCLOMETALATED IRIDIUM(III), Phosphorescence, Bimetallic strip
Abstract

We report the synthesis of pi-bonded ruthenium, rhodium, and iridium o-benzoquinones [Cp*M(o-C6H4O2)](n) [M = Ru (2), n = 1-; Rh (3), n = 0; Ir (4), n = 0] following a novel synthetic procedure. Compounds 2-4 were fully characterized by spectroscopic methods and used as chelating organometallic linkers, "OM-linkers", toward luminophore bricks such as Ru(bpy)(2)(2+), Rh(ppy)(2)(+), and Ir(ppy)(2)(+) (bpy = 2,2'-bipyridine; ppy = 2-phenylpyridine) for the design of a novel family of octahedral bimetallic complexes of the general formula [(L-L)(2)M(OM-linkers)[X](m) (X = counteranion; m = 0, 1, 2) whose luminescent properties depend on the choice of the OM-linker and the luminophore brick. Thus, dinuclear assemblies such as [(bpy)(2)Ru(2)][OTf] (5-OTf), [(bpy)(2)Ru(2)][Delta-TRISPHAT] (5-Delta T) {TRISPHAT = tris[tetrachlorobenzene-1,2-bis(olato)]phosphate}, [(bpy)(2)Ru(3)] [OTf](2) (6-OTf), [(bpy)(2)Ru(4)] [OTf](2) (7-OTf), [(bpy)(2)Ru(4)][Delta-TRISPHAT](2) (7-Delta T), [(ppy)(2)Rh(2)] (8), [(ppy)(2)Rh(3)][OTf] (9-OTf), [(ppy)(2)Rh(4)][OTf] (10-OTf), [(ppy)(2)Rh(4)[Delta-TRISPHAT] (10-Delta T), [(ppy)(2)Ir(2)] (11), [(ppy)(2)Ir(3)][OTf] (12-OTf), [(ppy)(2)Ir(4)][OTf] (13-OTf), and [(ppy)(2)Ir(4)][Delta-TRISPHAT] (13-Delta T) were prepared and fully characterized. The X-ray molecular structures of three of them, i.e., 5-OTf, 8, and 11, were determined. The structures displayed a main feature: for instance, the two oxygen centers of the OM-linker [Cp*Ru(o-C6H4O2)](-) (2) chelate the octahedral chromophore metal center, whether it be ruthenium, rhodium, or iridium. Further, the carbocycle of the OM-linker 2 adopts a eta(4)-quinone form but with some catecholate contribution due to metal coordination. All of these binuclear assemblies showed a wide absorption window that tailed into the near-IR (NIR) region, in particular in the case of the binuclear ruthenium complex 5-OTf with the anionic OM-linker 2. The latter feature is no doubt related to the effect of the OM-linker, which lights up the luminescence in these homo- and heterobinuclear compounds, while no effect has been observed on the UV-visible and emission properties because of the counteranion, whether it be triflate (OTf) or Delta-TRISPHAT. At low temperature, all of these compounds become luminescent; remarkably, the o-quinonoid linkers [Cp*M(o-C6H4O2)](n) (2-4) turn on red and NIR phosphorescence in the binuclear octahedral species 5-7. This trend was even more observable when the ruthenium OM-linker 2 was employed. These assemblies hold promise as NIR luminescent materials, in contrast to those made from organic 1,2-dioxolene ligands that conversely are not emissive.

Published
2012
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21. Activation of aliphatic C-H bonds by tetracyanobenzene photosensitization. A time-resolved and steady-state investigation

Author

Protti, Stefano, Fagnoni, Maurizio, Monti, Sandra, Rehault, Julien, Poizat, Olivier, Albini, Angelo, PhotoGreen Lab, Department of Chemistry, University of Pavia, Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 (LASIRE), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille Institut (CLIL), Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), Consiglio Nazionale delle Ricerche (CNR), Physikalisch-Chemisches Institut [Zürich], Universität Zürich [Zürich] = University of Zurich (UZH), Università degli Studi di Pavia = University of Pavia (UNIPV), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), and National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)

Subjects
Cyclohexane, 010405 organic chemistry, General Chemical Engineering, Radical, General Chemistry, 010402 general chemistry, Photochemistry, 01 natural sciences, Chemical reaction, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, chemistry.chemical_compound, Electron transfer, Radical ion, chemistry, Flash photolysis, Molecule, Triethylamine
Abstract

The photochemistry of 1,2,4,5-tetracyanobenzene (TCB) in acetonitrile in the presence of representative aliphatic donors (cyclohexane, 1,4-dioxane and triethylamine) has been investigated by femtosecond (fs) and nanoseconds (ns) flash photolysis as well as steady state irradiation in order to define the kinetic frame for the activation of aliphatic C-H bonds. Unlike in the case of aromatics, no ground state complex (except possibly in the case of triethylamine) or exciplex is formed. The lowest excited singlet is quenched and forms the free radical ions. The efficiency of the process, measured by the yield of TCB˙− (0.84 with cyclohexane, 0.15 with 1,4-dioxane, 0.37 with triethylamine) depends on the rate of return electron transfer, low for a high exothermicity. The chemical reaction following the electron transfer step depends on the properties of the radical cation. Thus, with cyclohexane deprotonation is slow and does not occur measurably on a microsecond scale, while on a longer time scale, the formation of alkyl radicals competes with back electron transfer between the free ions. The deprotonation of amine radical cations is faster and the resulting α-aminoalkyl radicals reduce a further molecule of TCB, causing the accumulation of the radical anion which is indefinitely stable in the absence of oxygen.

Published
2012
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22. Organometallic Quinonoid Linkers: A Versatile Tether for the Design of Panchromatic Ruthenium(II) Heteroleptic Complexes

Author

Barbara Ventura, Alessandra Degli Esposti, Lise-Marie Chamoreau, M. Rosa Axet, Andrea Barbieri, Hani Amouri, Aurélie Damas, Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), Consiglio Nazionale delle Ricerche (CNR), departament de quimica fisica i quimica inorganica i quimica analitica i quimica organica, Universitat Rovira i Virgili, Institut Parisien de Chimie Moléculaire (IPCM), Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), IRPPS-CNR, Salerno, Università degli Studi di Salerno (UNISA), Architectures Moléculaires (A.R.C), Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Salerno = University of Salerno (UNISA), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010405 organic chemistry, Chemistry, chemistry.chemical_element, [CHIM.CATA]Chemical Sciences/Catalysis, 010402 general chemistry, Photochemistry, 01 natural sciences, Combinatorial chemistry, 0104 chemical sciences, Ruthenium, Panchromatic film, Inorganic Chemistry, OCTAHEDRAL BIMETALLIC ASSEMBLIES, SENSITIZED SOLAR-CELLS, [CHIM]Chemical Sciences, Density functional theory, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Physical and Theoretical Chemistry, ComputingMilieux_MISCELLANEOUS
Abstract

The synthesis, X-ray structure determination, and photophysical investigation of a novel series of heteroleptic ruthenium(II) polypyridine complexes with organometallic linkers are reported. The displayed panchromatic absorption features are assigned by means of time-dependent density functional theory studies.

Published
2010
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23. The electronic properties of a homoleptic bisphosphine Cu(I) complex A joint theoretical and experimental insight

Author

Adrien Kaeser, Alessandra Degli Esposti, Jean-François Nierengarten, Gianluca Accorsi, Michel Holler, Béatrice Delavaux-Nicot, Nicola Armaroli, Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), Consiglio Nazionale delle Ricerche (CNR), Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de chimie moléculaire (LCM), and Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Valence (chemistry), 010405 organic chemistry, 010402 general chemistry, Condensed Matter Physics, 01 natural sciences, Biochemistry, 0104 chemical sciences, DENSITY-FUNCTIONAL THEORY, MOLECULAR-ORBITAL METHODS, EFFECTIVE CORE POTENTIALS, TRANSITION-METAL CATIONS, S/D EXCITATION-ENERGIES, PHOTOPHYSICAL PROPERTIES, COPPER(I) COMPLEXES, BASIS-SET, ADJUSTABLE-PARAMETERS, DIPHOSPHINE LIGANDS, chemistry.chemical_compound, Crystallography, chemistry, Computational chemistry, Excited state, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Singlet state, Physical and Theoretical Chemistry, Homoleptic, Triplet state, Lone pair, Basis set, Natural bond orbital
Abstract

The origin of the optical properties of the firstly reported stable luminescent [ Cu ( PP ) 2 ] + complex [ Cu ( dppb ) 2 ] + [ dppb = 1 , 2 - bis ( diphenylphosphino ) benzene ] is investigated using the exchange–correlation functional PBE0. The choice of the basis set used is discussed and a comparison with the results obtained by other functionals is performed. The role played by the bisphosphine ligands within the complex is elucidated by considering the electronic properties of the ligand alone to evidence how both the geometrical changes and the electronic interactions, induced by the inclusion of the metal cation, affect the electronic behavior of the whole system. The NBO analysis shows how the aryl groups of the ligands act as a reservoir of electrons within the complex. The electronic excitations of both the complex and of the ligand, calculated by including the solvation effects, allow to assign the lowest energy absorption broad band, recorded in CH 2 Cl 2 solution. The peculiar contribution of the phosphorus atoms to the description of the high occupied MOs and the participation of the copper cation to the description of the lowest singlet excited state, is pointed out. The origin of the observed phosphorescence of the complex is attributed to a triplet state, whose SOMO is characterized by the contributions of the valence 4 s and of the Rydberg 5 s AOs of the metal cation, along with the lone pair orbitals of the P atoms.

Published
2010
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24. Magnetic Analysis of MgFe Hydrotalcites as Powder and Dispersed in Thin Films within a Keratin Matrix.

Author

Dinelli F, Modestino M, Galluzzi A, Posati T, Seri M, Zamboni R, Sotgiu G, and Polichetti M

Abstract

Hydrotalcites (HTlcs) are a class of nanostructured layered materials that may be employed in a variety of applications, from green to bio technologies. In this paper, we report an investigation on HTlcs made of Mg and Fe, recently employed to improve the growth in vitro of osteoblasts within a keratin sponge. We carried out an analysis of powder materials and of HTlcs dispersed in keratin and spin-coated on a Si/SiO 2 substrate at different temperatures. A magnetic study of the powders was carried out with a Quantum Design Physical Property Measurement System equipped with a Vibrating Sample Magnetometer. The data gathered prove that these HTlcs are fully paramagnetic, and keratin showed a very small magnetic response. Optical and Atomic Force Microscopy analyses of the thin films provide a detailed picture of clusters randomly dispersed in the films with various dimensions. The magnetic properties of these films were characterized using the Nano Magneto Optical Kerr Effect (NanoMOKE) down to 7.5 K. The data collected show that the local magnetic properties can be mapped with a micrometric resolution distinguishing HTlc regions from keratin ones. This approach opens new perspectives in the characterization of these composite materials.

Published
2023
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25. Cyclodextrin-based metal-organic frameworks particles as efficient carriers for lansoprazole: Study of morphology and chemical composition of individual particles.

Author

Li X, Guo T, Lachmanski L, Manoli F, Menendez-Miranda M, Manet I, Guo Z, Wu L, Zhang J, and Gref R

Subjects
Crystallization, Cyclodextrins chemistry, Drug Delivery Systems, Lansoprazole administration & dosage, Metal-Organic Frameworks chemistry
Abstract

Cyclodextrin-based metal-organic frameworks (CD-MOFs) represent an environment-friendly and biocompatible class of MOFs drawing increasing attention in drug delivery. Lansoprazole (LPZ) is a proton-pump inhibitor used to reduce the production of acid in the stomach and recently identified as an antitubercular prodrug. Herein, LPZ loaded CD-MOFs were successfully synthesized upon the assembly with γ-CD in the presence of K + ions using an optimized co-crystallization method. They were characterized in terms of morphology, size and crystallinity, showing almost perfect cubic morphologies with monodispersed size distributions. The crystalline particles, loaded or not with LPZ, have mean diameters of around 6μm. The payloads reached 23.2±2.1% (wt) which corresponds to a molar ratio of 1:1 between LPZ and γ-CD. It was demonstrated that even after two years storage, the incorporated drug inside the CD-MOFs maintained its spectroscopic characteristics. Molecular modelling provided a deeper insight into the interaction between the LPZ and CD-MOFs. Raman spectra of individual particles were recorded, confirming the formation of inclusion complexes within the tridimensional CD-MOF structures. Of note, it was found that each individual particle had the same chemical composition. The LPZ-loaded particles had remarkable homogeneity in terms of both drug loading and size. These results pave the way towards the use of CD-MOFs for drug delivery purposes., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Published
2017
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26. Cyclodextrin-based nanocarriers containing a synergic drug combination: A potential formulation for pulmonary administration of antitubercular drugs.

Author

Salzano G, Wankar J, Ottani S, Villemagne B, Baulard AR, Willand N, Brodin P, Manet I, and Gref R

Subjects
Drug Combinations, Antitubercular Agents administration & dosage, Drug Carriers chemistry, Ethionamide administration & dosage, Hydroxamic Acids administration & dosage, Nanoparticles chemistry, Triazoles administration & dosage, beta-Cyclodextrins chemistry
Abstract

Tuberculosis (TB) remains a major global health problem. The use of ethionamide (ETH), a main second line drug, is associated to severe toxic side-effects due to its low therapeutic index. In this challenging context, "booster" molecules have been synthetized to increase the efficacy of ETH. However, the administration of ETH/booster pair is mostly hampered by the low solubility of these drugs and the tendency of ETH to crystallize. Here, ETH and a poorly water-soluble booster, so-called BDM43266, were simultaneously loaded in polymeric β-cyclodextrin nanoparticles (pβCyD NPs) following a "green" protocol. The interaction of ETH and BDM43266 with pβCyD NPs was investigated by complementary techniques. Remarkably, the inclusion of ETH and BDM43266 pβCyD NPs led to an increase of their apparent solubility in water of 10- and 90-fold, respectively. Competition studies of ETH and BDM43266 for the CyD cavities of pβCyD NPs corroborated the fact that the drugs did not compete with each other, confirming the possibility to simultaneously co-incorporate them in NPs. The drug-loaded NP suspensions could be filtered through 0.22μm filters. Finally, the drug-loaded NPs were passed through a Microsprayer ® to evaluate the feasibility to administer pβCyD NPs by pulmonary route. Each spray delivered a constant amount of both drugs and the NPs were totally recovered after passage through the Microsprayer ® . These promising results pave the way for a future use of pβCyD NPs for the pulmonary delivery of the ETH/BDM43266 pair., (Copyright © 2017. Published by Elsevier B.V.)

Published
2017
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27. Efficient loading of ethionamide in cyclodextrin-based carriers offers enhanced solubility and inhibition of drug crystallization.

Author

Wankar J, Salzano G, Pancani E, Benkovics G, Malanga M, Manoli F, Gref R, Fenyvesi E, and Manet I

Subjects
Crystallization, Solubility, Drug Carriers chemistry, Ethionamide chemistry, beta-Cyclodextrins chemistry
Abstract

Ethionamide (ETH) is a second line antitubercular drug suffering from poor solubility in water and strong tendency to crystallize. These drawbacks were addressed by loading ETH in β-cyclodextrin (βCyD)-based carriers. The drug was incorporated in a molecular state avoiding crystallization even for long-term storage and obtaining a tenfold increased solubility up to 25mM. The binding of ETH to polymeric βCyD nanoparticles (pβCyD NPs) was investigated in neutral aqueous medium by means of solubility phase diagrams, circular dichroism (CD) and UV-vis absorption and compared with the corresponding βCyD monomer. The binding constants and the absolute CD spectra of the drug complexes were determined by global analysis of multiwavelength data from spectroscopic titrations. The spectroscopic and photophysical properties of the complexes evidenced an alcohol-like environment for ETH included in the cavity. Additionally, ETH was found to be located not only in βCyD cavities, but also in confined microdomains inside the crosslinked NPs. This double modality of complexation together with a slightly higher binding constant makes the utilization of pβCyD NPs preferable over the monomeric βCyDs. In order to pave the way to future in vitro experiments, fluorescein labeled pβCyDs were synthesized. Interestingly the FITC labeling did not hamper the encapsulation of ETH and the drug improved the fluorescent signal of FITC molecules. The βCyD-based carriers appeared as versatile "green" systems for efficient incorporation and future delivery of ETH., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Published
2017
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28. Monocyclic β-lactams loaded on hydroxyapatite: new biomaterials with enhanced antibacterial activity against resistant strains.

Author

Giacomini D, Torricelli P, Gentilomi GA, Boanini E, Gazzano M, Bonvicini F, Benetti E, Soldati R, Martelli G, Rubini K, and Bigi A

Subjects
Anti-Bacterial Agents chemical synthesis, Azetidines chemistry, Azetidines pharmacology, Bacteria drug effects, Drug Carriers, Drug Liberation, Humans, Microbial Sensitivity Tests, Molecular Structure, Monobactams chemical synthesis, Spectroscopy, Fourier Transform Infrared, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents pharmacology, Biocompatible Materials chemistry, Durapatite chemistry, Monobactams chemistry, Monobactams pharmacology
Abstract

The development of biomaterials able to act against a wide range of bacteria, including antibiotic resistant bacteria, is of great importance since bacterial colonization is one of the main causes of implant failure. In this work, we explored the possibility to functionalize hydroxyapatite (HA) nanocrystals with some monocyclic N-thio-substituted β-lactams. To this aim, a series of non-polar azetidinones have been synthesized and characterized. The amount of azetidinones loaded on HA could be properly controlled on changing the polarity of the loading solution and it can reach values up to 17 wt%. Data on cumulative release in aqueous solution show different trends which can be related to the lipophilicity of the molecules and can be modulated by suitable groups on the azetidinone. The examined β-lactams-HA composites display good antibacterial activity against reference Gram-positive and Gram-negative bacteria. However, the results of citotoxicity and antibacterial tests indicate that HA loaded with 4-acetoxy-1-(methylthio)-azetidin-2-one displays the best performance. In fact, this material strongly inhibited the bacterial growth of both methicillin resistant and methicillin susceptible clinical isolates of S. aureus from surgical bone biopsies, showing to be a very good candidate as a new functional biomaterial with enhanced antibacterial activity.

Published
2017
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29. Halogen-Bond Effects on the Thermo- and Photochromic Behaviour of Anil-Based Molecular Co-crystals.

Author

Carletta A, Spinelli F, d'Agostino S, Ventura B, Chierotti MR, Gobetto R, Wouters J, and Grepioni F

Abstract

N-Salicilideneanilines are among the most studied thermo- and photochromic systems in the solid state. Although thermochromism is a general property of crystalline N-salicilideneanilines, photochromism is known in a limited number of cases. As a method for the construction of thermo- and photo-responsive molecular architectures, the co-crystallisation of 1,2,4,5-tetrafluoro-3,6-diiodobenzene (I2F4) with three selected imines of o-vanillin, named 1, 2 and 3, obtained through a condensation reaction with 3-aminopyridine, 4-bromoaniline and 4-iodoaniline, respectively, is reported herein. All crystals and co-crystals have been characterised by means of solid-state complementary techniques (X-ray diffraction, solid-state NMR spectroscopy, absorption and emission spectroscopy). The role of halogen bonding and crystal packing in the optical and chromic properties of all solid materials is discussed. All solids exhibit thermochromic behaviour, and three of them (2, 2 2 ⋅I2F4 and 3 2 ⋅I2F4) are also photochromic. Imine derivative 3 crystallises in two different polymorphic forms (3 A and 3 B) and a solvate (3 Solv ). The bromo and iodo derivatives, 2 and 3 B, are isomorphous and form isomorphous co-crystals with I2F4, but behave differently when exposed to UV light because only crystalline 2 is photochromic. Interestingly, the replacement of bromine with iodine seems to turn off the photochromism because crystalline 3 A and 3 Solv , and even the 2 0.7 3 0.3 solid solution, do not manifest photochromic behaviour., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Published
2017
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30. Characterization of polymorphic ampicillin forms.

Author

Baraldi C, Tinti A, Ottani S, and Gamberini MC

Subjects
Calorimetry, Differential Scanning, Chemistry, Pharmaceutical, Computer Simulation, Crystallization, Crystallography, X-Ray, Drug Stability, Hot Temperature, Molecular Structure, Phase Transition, Powder Diffraction, Spectroscopy, Fourier Transform Infrared, Spectrum Analysis, Raman, Technology, Pharmaceutical methods, Thermogravimetry, Time Factors, Ampicillin chemistry, Anti-Bacterial Agents chemistry
Abstract

In this work polymorphs of α-aminobenzylpenicillin (ampicillin), a β-lactamic antibiotic, were prepared and investigated by several experimental and theoretical methods. Amorphous monohydrate and three crystalline forms, the trihydrate, the crystal form I and the crystal form II, were investigated by FT-IR and micro-Raman. Also data obtained by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray powder diffraction (XRPD) and hot-stage Raman spectroscopy are reported. Finally, quantum mechanical calculations were performed by density functional theory (DFT) to assist the assignment of spectroscopic experimental bands. For the first time, the ampicillin molecule in its zwitterionic form was studied at the B3LYP/aug-cc-pVDZ level and the corresponding theoretical vibrational spectra were computed. In fact, ampicillin in the crystal is in zwitterionic form and concentrations of this same form are quite relevant in solutions at physiological pH. Experimental and theoretical results allowed identification of specific features for polymorph characterization. Bands typical of the different polymorphs are identified both in IR and Raman spectra: in particular in the NH stretching region (IR), in the amide I+δNH region (both techniques), in the 1520-1490cm(-1) region (IR), in the 1320-1300cm(-1) and 1280-1220cm(-1) (IR), in the 1200-1170cm(-1) (Raman), in the amide V region (IR), and, finally, in the 715-640cm(-1) and 220-200cm(-1) (Raman). Interconversion among different polymorphs was investigated by hot-stage Raman spectroscopy and thermal analysis, clarifying the complex pattern of transformations undergone as a function of temperature and heating rate. In particular, DSC scans show how the trihydrate crystals transform into anhydrous forms on heating. Finally, stability tests demonstrated, after a two years period, that no transformation or degradation of the polymorphs occurred., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Published
2014
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31. Host-guest interactions in Fe(III)-trimesate MOF nanoparticles loaded with doxorubicin.

Author

Anand R, Borghi F, Manoli F, Manet I, Agostoni V, Reschiglian P, Gref R, and Monti S

Subjects
Drug Stability, Free Radicals chemistry, Models, Molecular, Molecular Conformation, Porosity, Doxorubicin chemistry, Drug Carriers chemistry, Iron chemistry, Nanoparticles chemistry, Organometallic Compounds chemistry
Abstract

Doxorubicin (DOX) entrapment in porous Fe(III)-trimesate metal organic frameworks (MIL-100(Fe)) nanoparticles was investigated in neutral Tris buffer via UV-vis absorption, circular dichroism (CD), and fluorescence. The binding constants and the absolute spectra of the DOX-MIL-100(Fe) complexes were determined via absorption and fluorescence titrations. A binding model where DOX associates as monomer to the dehydrated Fe3O (OH)(H2O)2 [(C6H3)(CO2)3]2 structural unit in 1:1 stoichiometry, with apparent association constant of (1.1 to 1.8) × 10(4) M(-1), was found to reasonably fit the experimental data. Spectroscopic data indicate that DOX binding occurs via the formation of highly stable coordination bonds between one or both deprotonated hydroxyl groups of the aglycone moiety and coordinatively unsaturated Fe(III) centers. Complete quenching of the DOX fluorescence and remarkable thermal and photochemical stability were observed for DOX incorporated in the MIL-100(Fe) framework.

Published
2014
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32. Light energy collection in a porphyrin-imide-corrole ensemble.

Author

Ciuciu AI, Flamigni L, Voloshchuk R, and Gryko DT

Subjects
Molecular Structure, Zinc chemistry, Imides chemistry, Light, Metalloporphyrins chemistry, Porphyrins chemistry
Abstract

An assembly consisting of three units, that is, a meso-substituted corrole (C3), 1,8 naphthaleneimide (NIE), and a Zn porphyrin (ZnP), has been synthesized. NIE is connected to C3 through a 1,3-phenylene bridge and to the ZnP unit through a direct C-C bond. The convergent synthetic strategy includes the preparation of a trans-A2B-corrole possessing the imide unit, followed by Sonogashira coupling with a meso-substituted A3B-porphyrin. The photophysical processes in the resulting triad ZnP-NIE-C3 are examined and compared with those of the corresponding C3-NIE dyad and the constituent reference models C3, NIE, and ZnP. Excitation of the NIE unit in C3-NIE leads to a fast energy transfer of 98 % efficiency to C3 with a rate k(en) =7.5×10(10) s(-1), whereas excitation of the corrole unit leads to a reactivity of the excited state identical to that of the model C3, with a deactivation rate to the ground state k=2.5×10(8) s(-1). Energy transfer to C3 and to ZnP moieties follows excitation of NIE in the triad ZnP-NIE-C3. The rates are k(en) =7.5×10(10) s(-1) and k(en) =2.5×10(10) s(-1) for the sensitization of the C3 and ZnP unit, respectively. The light energy transferred from NIE to Zn porphyrin unit is ultimately funneled to the corrole component, which is the final recipient of the excitation energy absorbed by the different components of the array. The latter process occurs with a rate k(en) =3.4×10(9) s(-1) and 89 % efficiency. Energy transfer processes take place in all cases by a Förster (dipole-dipole) mechanism. The theory predicts quite satisfactorily the rate for the ZnP/C3 couple, where components are separated by about 23 Å, but results in calculated rates that are one to two orders of magnitude higher for the couples NIE/ZnP (D/A) and NIE/C3, which are separated by distances of about 14 and 10 Å, respectively., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Published
2013
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33. Scanning probe microscopy beyond imaging: a general tool for quantitative analysis.

Author

Liscio A

Abstract

A simple, fast and general approach for quantitative analysis of scanning probe microscopy (SPM) images is reported. As a proof of concept it is used to determine with a high degree of precision the value of observables such as 1) the height, 2) the flowing current and 3) the corresponding surface potential (SP) of flat nanostructures such as gold electrodes, organic semiconductor architectures and graphenic sheets. Despite histogram analysis, or frequency count (Fc), being the most common mathematical tool used to analyse SPM images, the analytical approach is still lacking. By using the mathematical relationship between Fc and the collected data, the proposed method allows quantitative information on observable values close to the noise level to be gained. For instance, the thickness of nanostructures deposited on very rough substrates can be quantified, and this makes it possible to distinguish the contribution of an adsorbed nanostructure from that of the underlying substrate. Being non-numerical, this versatile analytical approach is a useful and general tool for quantitative analysis of the Fc that enables all signals acquired and recorded by an SPM data array to be studied with high precision., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Published
2013
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34. β-Cyclodextrin polymer nanoparticles as carriers for doxorubicin and artemisinin: a spectroscopic and photophysical study.

Author

Anand R, Manoli F, Manet I, Daoud-Mahammed S, Agostoni V, Gref R, and Monti S

Subjects
Epichlorohydrin chemistry, Models, Molecular, Molecular Conformation, Particle Size, Artemisinins chemistry, Doxorubicin chemistry, Drug Carriers chemistry, Nanoparticles chemistry, Spectrum Analysis, beta-Cyclodextrins chemistry
Abstract

The association of doxorubicin (DOX) and artemisinin (ART) to a β-CyD-epichlorohydrin crosslinked polymer (pβ-CyD), organized in nanoparticles of ca. 15 nm size, was investigated in neutral aqueous medium by circular dichroism (CD), UV-vis absorption and fluorescence. The stability constants and the absolute CD spectra of the drug complexes were determined by global analysis of multiwavelength data from spectroscopic titrations. The polymer pβ-CyD proved able to disrupt the DOX dimer when the latter is the predominant form of DOX in solution. The spectroscopic and photophysical properties of the complexes evidenced an alcohol-like environment for ART and an improved inherent emission ability for DOX in the nanoparticle frame.

Published
2012
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35. Combination of spectroscopic and computational methods to get an understanding of supramolecular chemistry of drugs: from simple host systems to biomolecules.

Author

Monti S, Manet I, and Marconi G

Subjects
Animals, Cattle, Circular Dichroism, Cyclodextrins chemistry, Cyclodextrins metabolism, Ligands, Molecular Dynamics Simulation, Pharmaceutical Preparations chemistry, Protein Binding, Protein Structure, Tertiary, Serum Albumin, Bovine chemistry, Spectrophotometry, Ultraviolet, Pharmaceutical Preparations metabolism, Serum Albumin, Bovine metabolism
Abstract

Circular dichroism (CD) spectra of non-covalent ligand : biomolecule couples contain information on the equilibrium geometries of the associated structures that can be retrieved upon comparison of the sign and intensity of the experimental CD bands with the quantum mechanically calculated rotational strengths of low energy supramolecular complexes, obtained from molecular modelling methods. For both chiral and achiral ligands this approach proved useful to reach a structure based rationale of ground and excited state properties of the non-covalent ligand : protein associates. In this Perspective we illustrate the potential of this method focusing on the main achievements of our recent spectroscopic, conformational and photochemical studies on drug-albumin complexes and collocate it in the frame of current methodologies of molecular modelling and spectroscopic investigation of ligand : biomolecule binding.

Published
2011
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36. Multicolor, large-area fluorescence sensing through oligothiophene-self-assembled monolayers.

Author

Melucci M, Zambianchi M, Favaretto L, Palermo V, Treossi E, Montalti M, Bonacchi S, and Cavallini M

Abstract

We present a new strategy to realize self-assembled monolayers (SAMs) on quartz and silicon with a multicolour fluorescence pattern starting from a single, proton sensitive oligothiophene dye exposed at a defined pH. Fine tuning of the SAMs emission color over the entire visible range, including white, is demonstrated. Finally, integration of SAMs in patterned thin layer cells (TLCs) is exploited to demonstrate cation sensing potential in real devices.

Published
2011
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37. Unusual photoinduced electron transfer from a zinc porphyrin to a tetrapyridyl free-base porphyrin in a noncovalent multiporphyrin array.

Author

Ventura B, Flamigni L, Beyler M, Heitz V, and Sauvage JP

Abstract

Excitation of the peripheral Zn porphyrin units in a noncovalent five-porphyrin array, formed by gable-like zinc(II) bisporphyrins and a central free-base meso-tetrakis(4-pyridyl)porphyrin in a 2:1 ratio, (ZnP(2))(2).(TPyP), does not lead to a quantitative sensitization of the luminescence of the free-base porphyrin acceptor, even though there is an effective energy transfer. Time resolution of the luminescence evidences a quenching of TPyP upon sensitization by the peripheral ZnP(2). The time evolution of the TPyP fluorescence in the complex can be described by a bi-exponential fitting with a major component of 180 ps and a minor one of 5 ns, compared to an isolated TPyP lifetime of 9.4 ns. The two quenched lifetimes are shown to be correlated to the presence of 2:1 and 1:1 complexes, respectively. No quenching of TPyP fluorescence occurs in (ZnP(2))(2).(TPyP) at 77 K in a rigid solvent for which only an energy-transfer process (tau=150+/-10 ps) from peripheral ZnP(2) to the central TPyP is observed. An unusual HOMO-HOMO electron-transfer reaction from ZnP(2) to the excited TPyP units, responsible for the observed phenomena, is detected. The resulting charge-separated state, (ZnP(2))(+)(2).(TPyP)(-) is found to recombine to the ground state with a lifetime of 11 ns.

Published
2010
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38. Efficient dye-sensitized solar cells using red turnip and purple wild sicilian prickly pear fruits.

Author

Calogero G, Di Marco G, Cazzanti S, Caramori S, Argazzi R, Di Carlo A, and Bignozzi CA

Subjects
Molecular Structure, Photochemical Processes, Plant Extracts chemistry, Thermodynamics, Brassica napus chemistry, Coloring Agents chemistry, Fruit chemistry, Pyrus chemistry, Solar Energy
Abstract

Dye-sensitized solar cells (DSSCs) were assembled by using the bougainvillea flowers, red turnip and the purple wild Sicilian prickly pear fruit juice extracts as natural sensitizers of TiO(2) films. The yellow orange indicaxanthin and the red purple betacyanins are the main components in the cocktail of natural dyes obtained from these natural products. The best overall solar energy conversion efficiency of 1.7% was obtained, under AM 1.5 irradiation, with the red turnip extract, that showed a remarkable current density (Jsc = 9.5 mA/cm(2)) and a high IPCE value (65% at lambda = 470 nm). Also the purple extract of the wild Sicilian prickly pear fruit showed interesting performances, with a Jsc of 9.4 mA/cm(2), corresponding to a solar to electrical power conversion of 1.26%.

Published
2010
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39. Photoactive corrole-based arrays.

Author

Flamigni L and Gryko DT

Abstract

The collection and conversion of light energy into chemical energy is based on the use of molecular structures of various complexity, where the absorbed light energy is first converted into an excited state able to undergo energy or electron transfer processes and finally it is stored in a charge separated state as chemical (electrochemical) potential. A bio-mimetic approach has seen tetrapyrroles number among the most common components of these arrays. This tutorial review reports on the use of relatively new tetrapyrroles, corroles, in this field. A brief presentation of the electrochemical and photophysical properties of the corrole units relevant to the application is presented together with a discussion on the photo- and thermal stability issues, followed by an overview of the activity and improvements in the preparation of photo-active molecular arrays containing corroles.

Published
2009
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40. Energy transfer processes in electronically coupled porphyrin hetero-dyads connected at the beta position.

Author

Ventura B, Barigelletti F, Lodato F, Officer DL, and Flamigni L

Abstract

Energy transfer in a series of hetero-dyads of zinc porphyrin and free-base porphyrin connected at the beta position by pi conjugated bridges has been determined. The dyads have been characterized and compared with the homo dyads, excellent models for the donor and the acceptor porphyrins in the electronically conjugated system. The homo dyads provide reliable parameters for the determination of the energy transfer rate calculated according to the Förster theory. This model was inadequate to account for the experimental findings and an electron exchange mechanism was shown to contribute. A favorable coplanar arrangement of the bridge and the tetrapyrroles facilitates the energy transfer process, which displays a very low distance dependence and an efficiency >98%.

Published
2009
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41. Self-organization, optical, and electrical properties of alpha-quinquethiophene-dinucleotide conjugates.

Author

Alesi S, Brancolini G, Viola I, Capobianco ML, Venturini A, Camaioni N, Gigli G, Melucci M, and Barbarella G

Subjects
Circular Dichroism, Electrochemistry methods, Luminescence, Microscopy, Confocal, Molecular Conformation, Molecular Structure, Oligonucleotides chemistry, Photochemistry methods, Thiophenes chemical synthesis, Models, Molecular, Oligonucleotides chemical synthesis, Thiophenes chemistry
Abstract

The synthesis and properties of (5')TA(3')-t5 (8a) and (5')CG(3')-t5 (8b) conjugates, in which the self-complementary dinucleotides TA and CG are covalently bound to the central ring of alpha-quinquethiophene (t5), are described. According to molecular mechanics calculations, the preferred conformation of both 8a and 8b is that with the dinucleotide folded over the planar t5 backbone, with the nucleobases facing t5 at stacking distance. The calculations show that the aggregation process of 8a and 8b is driven by a mix of nucleobase-thiophene interactions, hydrogen bonding between nucleobases (non Watson-Crick (W&C) in TA, and W&C in CG), van der Waals, and electrostatic interactions. While 8b is scarcely soluble in any solvents, 8a is soluble in water, indicating that the aggregates of the former are more stable than those of the latter. Microfluidic-induced self-assembly studies of 8a showed the formation of lamellar, spherulitic, and dendritic supramolecular structures, depending on the concentration and solvent evaporation time. The self-assembled structures displayed micrometer dimensions in the xy plane of the substrate and nanometer dimensions in the z direction. Spatially resolved confocal microscopy and spectroscopy showed that the aggregates were characterized by intense fluorescence emission. Cast films of 8a from water solutions showed chirality transfer from the dinucleotide to t5. The hole mobility of the cast films of 8a was estimated using a two-electrode device under high vacuum and found to be up to two orders of magnitude greater than those previously measured for dinucleotide-quarterthiophene conjugates under the same experimental conditions.

Published
2009
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42. Revealing phenylium, phenonium, vinylenephenonium, and benzenium ions in solution.

Author

Manet I, Monti S, Grabner G, Protti S, Dondi D, Dichiarante V, Fagnoni M, and Albini A

Subjects
Benzene Derivatives radiation effects, Ions chemistry, Ions radiation effects, Models, Chemical, Molecular Structure, Photochemistry, Solutions chemistry, Solutions radiation effects, Stereoisomerism, Time Factors, Ultraviolet Rays, Benzene Derivatives chemistry
Abstract

The 4-methoxyphenylium ion has been generated in the triplet state ((3)An(+)) by photolysis of 4-chloroanisole in polar media and detected by flash photolysis (lambda(max)=400 nm). This is the first detection of a phenylium ion in solution by flash photolysis and the assignment is supported by time-dependent density functional theory (TD-DFT) calculations. In neat solvents, the cation was reduced to anisole, a process initiated by electron transfer from the starting compound ((3)An(+)+AnCl-->An(*)+AnCl(*+), with the radical cation detected at 470 nm, then An(*)-->AnH). Addition of pi nucleophiles to the (3)An(+) cation offers a novel access to a number of other cationic intermediates under mild, nonacidic conditions. Two intermediates are successively formed with alkenes, a diradical cation and the phenonium ion, which are detected at 440 and 320 nm, respectively, by flash photolysis and are in accordance with calculations. Allylanisoles or beta-alkoxyalkylanisoles are the end products, with a small amount of alpha-alkoxyalkylanisoles that arises from a Wagner-Meerwein rearrangement to form benzyl cations. Further intermediates that have been predicted and detected are the phenylvinylium ion, possibly in equilibrium with the vinylenephenonium ion, with 1-hexyne (lambda(max)=340 nm) and the benzenium ion with benzene (lambda(max)=380 nm). The final products were anisylhexyne and methoxybiphenyl (an analogous product and intermediate were detected with thiophene).

Published
2008
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43. Binding and photochemistry of enantiomeric 2-(3-benzoylphenyl)propionic acid (ketoprofen) in the human serum albumin environment.

Author

Monti S, Manet I, Manoli F, and Sortino S

Subjects
Binding Sites, Circular Dichroism methods, Humans, Ketoprofen radiation effects, Lasers, Photochemistry, Photolysis, Quantum Theory, Serum Albumin radiation effects, Spectrometry, Fluorescence methods, Stereoisomerism, Ketoprofen chemistry, Serum Albumin chemistry
Abstract

Global analysis of circular dichroism multiwavelength data and time resolved fluorescence was applied to investigate the interaction of R(-)- and S(+)-ketoprofen (KP) with human serum albumin (HSA) in buffer solution at neutral pH. The most stable drug:protein adducts of 1 : 1 and 2 : 1 stoichiometry were characterized as regards the stability constants and the absolute circular dichroism spectra. The spectra of the diastereomeric 1 : 1 conjugates are negative with minima at ca. 350 nm for R(-)-KP and 330 nm for S(+)-KP, those of the 2 : 1 complexes are both negative with minimum at 340 nm and quite similar in shape to each other, thereby showing that the protein loses chiral recognition capability upon multiple binding. HSA intrinsic time resolved fluorescence data obtained exciting at 295 nm point to Trp 214 being located in the secondary binding site for both KP enantiomers. The photodegradation of the S(+)- and R(-)-KP:HSA complexes was studied by steady state photolysis using lambda(irr) > 320 nm. No decrease of the photodegradation quantum yields was observed in 1 : 1 complexes. An induction time for the photodegradation course in 2 : 1 complexes was observed. Transient absorption spectroscopy at lambda(exc) = 355 nm showed that triplet KP species were formed with stereo-differentiated lifetimes and high quantum yields (0.7-0.9). Secondary transients were consistent with the occurrence of photodecarboxylation and/or photoreduction within the protein matrix.

Published
2007
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44. Diastereoselectivity and site dependency in the photochemistry of ketoprofen in the bovine serum albumin matrix.

Author

Monti S, Manet I, Manoli F, Morrone R, Nicolosi G, and Sortino S

Subjects
Anti-Inflammatory Agents, Non-Steroidal chemistry, Anti-Inflammatory Agents, Non-Steroidal radiation effects, Photolysis, Ketoprofen chemistry, Ketoprofen radiation effects, Serum Albumin, Bovine chemistry
Abstract

The photodegradation of the S(+)- and R(-)-ketoprofen (KP) enantiomers in the bovine serum albumin matrix was studied by steady-state photolysis with the use of lambda(irr) > 320 nm and transient absorption spectroscopy with lambda(exc) = 355 nm, at 1/1 and 2/1 KP/BSA molar ratios. R(-)-KP was found to be more labile than S(+). Triplet ketoprofen species were evidenced with lifetimes of 400 ns for S(+) and 600 ns for R(-)-KP. Further longer-lived transients with lifetimes of 2.6 and 6.0 mus for S(+) and R(-), respectively, were detected. On the basis of the binding constants of the drug enantiomers to the two main binding sites of the protein, obtained from circular dichroism experiments, the individual disappearance quantum yields of the 1:1 and 2:1 diastereomeric KP:BSA complexes could be estimated. The photoreactivity in the BSA matrix was rationalized on the basis of diastereoselective photodecarboxylation in the two main protein sites.

Published
2006
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45. Binding of a chiral drug to a protein: an investigation of the 2-(3-benzoylphenyl)propionic acid/bovine serum albumin system by circular dichroism and fluorescence.

Author

Monti S, Manoli F, Sortino S, Morrone R, and Nicolosi G

Subjects
Animals, Binding Sites, Cattle, Chemistry, Pharmaceutical methods, Hydrogen-Ion Concentration, Models, Statistical, Molecular Conformation, Protein Binding, Spectrophotometry methods, Stereoisomerism, Time Factors, Anti-Inflammatory Agents, Non-Steroidal chemistry, Circular Dichroism methods, Ketoprofen chemistry, Serum Albumin, Bovine chemistry, Spectrometry, Fluorescence methods
Abstract

A combined approach using global analysis of circular dichroism multiwavelength data and time resolved fluorescence was applied to investigate the interaction of R-(-)- and S-(+)-ketoprofen with bovine serum albumin in buffer solution at neutral pH. A characterization of the most stable drug : protein adducts of 1 : 1 and 2 : 1 stoichiometry, as individual chemical species, was obtained. The stability constants and the absolute circular dichroism spectra of the diastereomeric complexes were determined. The spectra of the 1 : 1 conjugates are opposite in sign, those of the 2 : 1 complexes are both negative, but different in shape from each other (peaks at 358 and 342 nm for S-(+)- and R-(-)-ketoprofen, respectively). A tryptophan residue was shown to be involved in the binding of the drug, in the primary site for the R-(-) and in the secondary site for the S-(+) enantiomer, thereby showing that chiral recognition by the protein causes the site of highest affinity being not the same for both optical antipodes.

Published
2005
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46. Sensitization of nanocrystalline TiO2 with black absorbers based on Os and Ru polypyridine complexes.

Author

Altobello S, Argazzi R, Caramori S, Contado C, Da Fré S, Rubino P, Choné C, Larramona G, and Bignozzi CA

Abstract

New metal complexes of the type [M(H3tcterpy)LY]+ (where M = Os(II) or Ru(II), L = substituted or unsubstituted bipyridine or pyridylquinoline, and Y = Cl-, I-, or SCN-) have been designed, synthesized, and characterized in view of their application for dye-sensitized solar cells (DSSCs). The Os dyes show a very broad absorption, and correspondingly, the DSSCs show an unprecedented spectral response in the NIR, with an onset at 1100 nm, reaching values of about 50% at 900 nm. The integrated photocurrent of some of such Os dyes is similar to that of the well-known [Ru(Htcterpy)(NCS)3](TBA) and superior to that of the [Ru(Hdcbpy)2(NCS)2](TBA)2 sensitizer. The Ru dyes show absorption and DSSC spectral response between those of the red and black dyes. Their advantage is their potential superior stability due to the reversible oxidative electrochemistry.

Published
2005
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47. The electron transfer rate of large TPA based compounds: a joint theoretical and electrochemical approach.

Author

Degli Esposti A, Fattori V, Sabatini C, Casalbore-Miceli G, and Marconi G

Subjects
Aniline Compounds analysis, Computer Simulation, Electric Impedance, Electron Transport, Light, Aniline Compounds chemistry, Aniline Compounds radiation effects, Electrochemistry methods, Models, Chemical, Models, Molecular, Photochemistry methods
Abstract

A series of triphenylamine (TPA) based compounds is investigated by means of density functional theory and cyclic voltammetry. Using the Nicholson's formalism, the measured deltaE(p) are correlated with B3LYP/6-31G* calculated reorganisation energies (lambda), elucidating the trend followed by the electron transfer rate of these compounds. Besides the direct dependency upon the dimension of the cationic fragment contributing to the hole stabilisation, the lambdas are tuned by the symmetry local to the TPA units, as evidenced by the structural relaxation of the cations. MDTAB shows the interesting combination of low ionisation potential (IP) and low lambda. This can make this compound interesting for practical applications in organic light emitting diode (OLEDs) devices, due to the direct correlation of the IP and lambda with the hole transfer efficiency to the anode, along with the hole mobility.

Published
2005
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48. Antitumor agents 4. Characterization of free radicals produced during reduction of the antitumor drug 5H-pyridophenoxazin-5-one: an EPR study.

Author

Alberti A, Bolognese A, Guerra M, Lavecchia A, Macciantelli D, Marcaccio M, Novellino E, and Paolucci F

Subjects
Antineoplastic Agents blood, Cell Survival drug effects, Comet Assay, DNA Damage, Electrochemistry, Electron Spin Resonance Spectroscopy methods, Free Radicals blood, Growth Inhibitors blood, Growth Inhibitors chemistry, Growth Inhibitors metabolism, Humans, Intercalating Agents chemistry, Intercalating Agents metabolism, Intercalating Agents pharmacology, Lymphocytes chemistry, Lymphocytes cytology, Lymphocytes metabolism, Male, Oxazines blood, Oxidation-Reduction, Antineoplastic Agents chemistry, Antineoplastic Agents metabolism, Free Radicals chemistry, Free Radicals metabolism, Oxazines chemistry, Oxazines metabolism
Abstract

5H-Pyridophenoxazin-5-one (PPH), a new anticancer iminoquinone, is able to inhibit a large number of lymphoblastoid and solid tumor-derived cells at submicromolar concentrations. Molecular modeling calculations indicated that this compound might intercalate into the DNA double strand. This was also supported by nuclear magnetic resonance studies. Since free radicals arising from anticancer quinonic drugs have been proposed to be key species responsible for DNA cleavage, we have aimed to intercept and identify free radicals from PPH generated under bioreductive conditions. The first and second monoelectronic reduction potentials of PPH were measured by means of cyclic voltammetry: the reduction potential of PPH is compatible with its reduction by compounds such as NADH, and suggested that reduction of PPH may play a role in its cytotoxicity. The radical anion PPH(*)(-) was detected by means of electron paramagnetic resonance spectroscopy, and its identification was supported by DFT calculations. EPR experiments in the presence of spin traps 5,5-dimethylpyrroline N-oxide and 5-(diethoxyphosphoryl)-5-methylpyrroline N-oxide suggested the occurrence of an electron transfer between the radical anion of the drug and oxygen resulting in the formation of the superoxide anion (O(2)(*)(-)). The enthalpy of the reaction of PPH(*)(-) with O(2) was determined both in the gas phase and in solution at the B3LYP/6-31+G level using the isodensity PCM method, and the overall process in dimethyl sulfoxide was predicted to be slightly exothermic. We propose that the monoelectronic reduction of PPH in the proximity of DNA may eventually lead to radicals that could cause considerable damage to DNA, thus accounting for the high cytotoxic activity of the drug. Indeed, a comet assay (alkaline single-cell electrophoresis) showed that PPH causes free radical-induced DNA damage.

Published
2003
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49. A new facile synthesis of tertiary dithioesters.

Author

Alberti A, Benaglia M, Laus M, and Sparnacci K

Abstract

Thermal decomposition of tertiary azo compounds in the presence of a triphenylmethyl dithioester results in the formation of the corresponding tertiary dithioesters. This procedure is especially useful for the synthesis of tertiary phosphoryldithioformates, but also represents an easy synthetic methodology of general applicability.

Published
2002
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