Search

Your search keyword '"Alary, Fabienne"' showing total 180 results
Start Over Author "Alary, Fabienne"
180 results on '"Alary, Fabienne"'

5. Synthesis and Characterization of New Thiazolidinones Containing Coumarin Moieties and Their Antibacterial and Antioxidant Activities

Author

Alary Fabienne, Ridha Ben Said, Abdullah Sulaiman Al-Ayed, and Naceur Hamdi

Subjects
coumarin, ethyl bromoacetate, thiazolidinones, DFT studies, antibacterial activities, Organic chemistry, QD241-441
Abstract

New coumarin derivatives, namely (2-(4-methyl-2-oxo-2H-chromen-7-yloxy)-N-(4-oxo-2-phenylthiazolidin-3-yl)acetamide, N-(2-(3-methoxyphenyl)-4-oxothiazolidin-3-yl)-2-(4-methyl-2-oxo-2H-chromen-7-yloxy)acetamide, 2-(4-methyl-2-oxo-2H-chromen-7-yloxy)-N-(4-oxo-2-(2,3,4trimethoxyphenyl)thiazolidin-3-yl)acetamide and N-(2-(4-bromophenyl)-4-oxothiazolidin-3-yl)-2-(4-methyl-2-oxo-2H-chromen-7-yloxy)acetamide) were synthesized starting from 4-methyl-7-hydroxycoumarin. The structures of the obtained compounds were confirmed by analytical IR and NMR spectra to elucidate the different positions of protons and carbons and as well as theoretical studies (DFT/B3LYP). The new compounds were screened for antibacterial activity. Most of them are more active against E. coli S. aureus and B. subtilis than standard references.

Published
2012
Full Text
View/download PDF

13. Phenyl-pyta-tricarbonylrhenium(i) complexes: combining a simplified structure and steric hindrance to modulate the photoluminescence properties

Author

Poirot, Alexandre, primary, Vanucci-Bacqué, Corinne, additional, Delavaux-Nicot, Béatrice, additional, Leygue, Nadine, additional, Saffon-Merceron, Nathalie, additional, Alary, Fabienne, additional, Bedos-Belval, Florence, additional, Benoist, Eric, additional, and Fery-Forgues, Suzanne, additional

Published
2021
Full Text
View/download PDF

14. Not All 3MC States Are the Same: The Role of 3MCcisStates in the Photochemical N∧N Ligand Release from [Ru(bpy)2(N∧N)]2+Complexes

Author

Eastham, Katie, Scattergood, Paul A., Chu, Danny, Boota, Rayhaan Z., Soupart, Adrien, Alary, Fabienne, Dixon, Isabelle M., Rice, Craig R., Hardman, Samantha J. O., and Elliott, Paul I. P.

Abstract

Ruthenium(II) complexes feature prominently in the development of agents for photoactivated chemotherapy; however, the excited-state mechanisms by which photochemical ligand release operates remain unclear. We report here a systematic experimental and computational study of a series of complexes [Ru(bpy)2(N∧N)]2+(bpy = 2,2′-bipyridyl; N∧N = bpy (1), 6-methyl-2,2′-bipyridyl (2), 6,6′-dimethyl-2,2′-bipyridyl (3), 1-benzyl-4-(pyrid-2-yl)-1,2,3-triazole (4), 1-benzyl-4-(6-methylpyrid-2-yl)-1,2,3-triazole (5), 1,1′-dibenzyl-4,4′-bi-1,2,3-triazolyl (6)), in which we probe the contribution to the promotion of photochemical N∧N ligand release of the introduction of sterically encumbering methyl substituents and the electronic effect of replacement of pyridine by 1,2,3-triazole donors in the N∧N ligand. Complexes 2to 6all release the ligand N∧N on irradiation in acetonitrile solution to yield cis-[Ru(bpy)2(NCMe)2]2+, with resultant photorelease quantum yields that at first seem counter-intuitive and span a broad range. The data show that incorporation of a single sterically encumbering methyl substituent on the N∧N ligand (2and 5) leads to a significantly enhanced rate of triplet metal-to-ligand charge-transfer (3MLCT) state deactivation but with little promotion of photoreactivity, whereas replacement of pyridine by triazole donors (4and 6) leads to a similar rate of 3MLCT deactivation but with much greater photochemical reactivity. The data reported here, discussed in conjunction with previously reported data on related complexes, suggest that monomethylation in 2and 5sterically inhibits the formation of a 3MCcisstate but promotes the population of 3MCtransstates which rapidly deactivate 3MLCT states and are prone to mediating ground-state recovery. On the other hand, increased photochemical reactivity in 4and 6seems to stem from the accessibility of 3MCcisstates. The data provide important insights into the excited-state mechanism of photochemical ligand release by Ru(II) tris-bidentate complexes.

Published
2022
Full Text
View/download PDF

15. Using effective group potential methodology for predicting organometallic complex properties

Author

Alary, Fabienne, Heully, Jean-Louis, Poteau, Romuald, Maron, Laurent, Trinquier, Georges, and Daudey, Jean-Pierre

Subjects
Cyclopentadiene -- Chemical properties, Coordination compounds -- Research, Organometallic compounds -- Chemical properties, Chemistry
Abstract

Optimal geometries, harmonic vibrational frequencies, and relative energies of different sets of metal complexes are calculated using the effective group potentials (EGP) method. All of the systems under consideration contain the cyclopentadienyl (Cp) ligand.

Published
2003

17. Modeling C (sub)5 H(sub)5 with atoms or effective group potential in lanthanide complexes: isolobality not the determining factor

Author

Maron, Laurent, Eisenstein, Odile, Alary, Fabienne, and Poteau, Romuald

Subjects
Chemistry, Physical and theoretical -- Research, Rare earth metals -- Physiological aspects, Coordination compounds -- Physiological aspects, Atoms -- Physiological aspects, Carbon -- Physiological aspects, Hydrogen -- Physiological aspects, Chemicals, plastics and rubber industries
Published
2002

20. Unravelling the Mechanism of Excited-State Interligand Energy Transfer and the Engineering of Dual Emission in [Ir(C∧N)2(N∧N)]+ Complexes

Author

Scattergood, Paul A., primary, Ranieri, Anna M., additional, Charalambou, Luke, additional, Comia, Adrian, additional, Ross, Daniel A. W., additional, Rice, Craig R., additional, Hardman, Samantha J. O., additional, Heully, Jean-Louis, additional, Dixon, Isabelle M., additional, Massi, Massimiliano, additional, Alary, Fabienne, additional, and Elliott, Paul I. P., additional

Published
2020
Full Text
View/download PDF

22. Application of [Pt(II)(Tetra-Tert-Butylsalophen)] Complex within Organic Devices: Deep Red Emission, Bistable Light-Emitting Diodes and Operational Stability

Author

Blondel, Benoît, Colin, Anaïs, Lopes, Manuel, Alary, Fabienne, Zissis, Georges, Sasaki, Isabelle, Renaud, Cédric, LAboratoire PLasma et Conversion d'Energie (LAPLACE), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Photochimie théorique et computationnelle (LCPQ) (PTC), Laboratoire de Chimie et Physique Quantiques (LCPQ), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Lumière et Matière (LAPLACE-LM), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), 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), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3)

Subjects
[SDV]Life Sciences [q-bio], [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, [CHIM]Chemical Sciences, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2018
Full Text
View/download PDF

23. Propriétés structurelles et photophysiques du 3- hexylthiophène (P3HT) : études expérimentale et théorique combinées

Author

FAROUIL, Léa, Alary, Fabienne, Bedel-Pereira, Eléna, Séguy, Isabelle, Heully, Jean-Louis, Photochimie théorique et computationnelle (LCPQ) (PTC), Laboratoire de Chimie et Physique Quantiques (LCPQ), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Équipe Matériaux et Procédés pour la Nanoélectronique (LAAS-MPN), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Équipe MICrosystèmes d'Analyse (LAAS-MICA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)

Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry
Abstract

National audience; L'objectif de ce travail est la mise au point d'une photodiode organique (OPD) intégrée dans un microsystème de détection basé sur les propriétés de luminescence d'une micro-algue. L'OPD est élaborée à partir d'un polymère à faible gap, le PTB7 (efficacité quantique extérieure élevée de 80% lorsqu'il est, associé au PC71BM) [1]. L'optimisation de l'OPD passe par la compréhension théorique des propriétés photophysiques des composés. Aussi, un protocole utilisant des calculs TD-DFT et DFT a été mis au point en s'appuyant sur le P3HT, composé très étudié dans la littérature. Les spectres Raman, infrarouge, d'absorption UV-visible résolu en vibrations (Figure 1) et de photoluminescence (PL) simulés présentent un très bon accord avec les spectres expérimentaux, validant la méthode utilisée. Par ailleurs, nous démontrons que la structure vibronique est due à un mode collectif dominé par l'élongation des liaisons CC inter-cycles et intra-cycles et couplée au mode de vibration des chaînes alkyle. En optimisant et en décrivant les états excités les plus bas de ces oligothiophènes (états singulet S1 et triplet T1), nous montrons également que S1 et T1 présentent une structure quinoïdale avec une distribution de spin localisée sur la partie centrale de la chaîne. Les énergies relatives des deux états excités les plus bas offrent la possibilité à ces systèmes d'être impliqués dans le processus de fission d'excitons de singulet. Ayant démontré que les méthodes ab-initio modernes sont capables de décrire avec de bonnes précisions les propriétés vibrationnelles et optoélectroniques des chaînes de polymères et, d'estimer l'impact de la longueur de chaîne des oligomères, nos efforts théoriques actuels sont axés sur l'étude des propriétés du polymère pour notre photodiode, le PTB7. Références : [1] C.

Published
2017

24. Revisiting the structural and photophysical properties of 3- hexylthiophene (P3HT): a combined experimental and theoretical study

Author

FAROUIL, Léa, Alary, Fabienne, Bedel-Pereira, Eléna, Séguy, Isabelle, Heully, Jean-Louis, Photochimie théorique et computationnelle (LCPQ) (PTC), Laboratoire de Chimie et Physique Quantiques (LCPQ), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Équipe Matériaux et Procédés pour la Nanoélectronique (LAAS-MPN), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Équipe MICrosystèmes d'Analyse (LAAS-MICA), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)

Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry
Abstract

International audience; The context of our work is to design a lab-on-chip based on the luminescence properties of a micro-algae: Chlamydomonas reinhardtii. The algae luminescence is collected thanks to an organic photodiode (OPD) based on a low band gap polymer, PTB7 (high external quantum efficiency of 80% when mixed with PC71BM) [1]. Before ab-initio calculations simulating those systems, we perform these calculations (TD-DFT and DFT) on the experimentally and theoretically extensively studied P3HT in order to identify the best-adapted simulation's methodology. We will demonstrate here how modern ab-initio methods are able to describe with good precisions vibrational and optoelectronical properties of those polymers chains and particularly to estimate the impact of the chain-length of oligomers (eight units to twenty units). Raman (figure 1), infrared, vibrationally resolved UV-visible absorption (figure 2) and photoluminescence (PL) spectra have been simulated. Their comparison with their respective experimental spectra shows a perfect agreement. We demonstrate that the vibronic structure is due to a collective mode, dominated by interring CC bond stretching, coupled to alkyl chains vibration mode. By optimizing and describing the lowest excited states of these oligothiophenes (singlet S1 and triplet states T1), we find that S1 and T1 present a quinoidal structure with a spin distribution localized on the central part of the chain. Relative energies of the two lowest excited states provide the possibility to these systems to be involved in singlet exciton fission process. As a result of this work, we have checked that our method is able to predicted P3HT photophysical properties. Further theoretical and experimental efforts are now focus on PTB7 studies, and we are confident on our calculation method for various polymers. [1] C.

Published
2017

29. Spin-orbit effects on the photophysical properties of Ru(bpy)32+.

Author

Heully, Jean-Louis, Alary, Fabienne, and Boggio-Pasqua, Martial

Subjects
*CHARGE transfer, *POTENTIAL energy surfaces, *ION exchange (Chemistry), *LIGANDS (Chemistry), *SPIN excitations
Abstract

We present in this article a detailed study of the photophysics of the Ru(bpy)32+ complex based on a formalism using density functional theory and an a posteriori treatment of the spin-orbit coupling. The absorption and emission spectra were computed and a very good agreement was obtained with the available experimental data. This work also reveals for the first time that the triplet metal-centered (MC) dd state cannot deactivate radiatively and corresponds to a transient structure for the nonradiative de-excitation of the triplet metal-to-ligand charge transfer (MLCT) state. Thus, a competition takes place between the luminescence of the MLCT state and nonradiative decay back to the ground state via population of the MC state. This radiationless return to the ground state occurs via a deactivation funnel which has been characterized for the first time by optimizing the minimum energy crossing point between the triplet MC and singlet ground state potential energy surfaces. Its low-lying energy position relative to the energy necessary to access the MC minimum suggests that this funnel will be readily accessible. [ABSTRACT FROM AUTHOR]

Published
2009
Full Text
View/download PDF

30. Spin-orbit effects on the photophysical properties of Ru(bpy)32+.

Author

Heully, Jean-Louis, Alary, Fabienne, and Boggio-Pasqua, Martial

Subjects
CHARGE transfer, POTENTIAL energy surfaces, ION exchange (Chemistry), LIGANDS (Chemistry), SPIN excitations
Abstract

We present in this article a detailed study of the photophysics of the Ru(bpy)32+ complex based on a formalism using density functional theory and an a posteriori treatment of the spin-orbit coupling. The absorption and emission spectra were computed and a very good agreement was obtained with the available experimental data. This work also reveals for the first time that the triplet metal-centered (MC) dd state cannot deactivate radiatively and corresponds to a transient structure for the nonradiative de-excitation of the triplet metal-to-ligand charge transfer (MLCT) state. Thus, a competition takes place between the luminescence of the MLCT state and nonradiative decay back to the ground state via population of the MC state. This radiationless return to the ground state occurs via a deactivation funnel which has been characterized for the first time by optimizing the minimum energy crossing point between the triplet MC and singlet ground state potential energy surfaces. Its low-lying energy position relative to the energy necessary to access the MC minimum suggests that this funnel will be readily accessible. [ABSTRACT FROM AUTHOR]

Published
2009
Full Text
View/download PDF

31. A study of the correlation effects upon the modelization of the double exchange phenomenon.

Author

Carissan, Yannick, Heully, Jean-Louis, Guihéry, Nathalie, and Alary, Fabienne

Subjects
TRANSITION metals, MOLECULAR rotation, FERROMAGNETISM, ELECTRIC conductivity, HAMILTONIAN systems, SPECTRUM analysis
Abstract

A previous work by the authors has shown that the usual spin Hamiltonian used to model the magnetic spectra of mixed valence compounds was not sufficient to reproduce the magnetic spectrum of the molecule [Fe2(OH)3(NH3)6]2+. In the present paper, the spin Hamiltonian is confronted to correlated ab initio calculations. The discrepancy between this Hamiltonian and the calculations is investigated and explained. It is pointed out that the multiconfigurational nature of the transition metal is responsible for this discrepancy. However, we show that this effect can easily be treated at the complete active space self-consistent field (CASSCF) level and that no further correlation treatment is needed. The spin Hamiltonian, which reproduces very well the minimal CASSCF results, could not be improved to recover the multireference effects. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2004
Full Text
View/download PDF

32. The effective group potential, a new method for the study of spectrum in large molecules: Tests and perspectives.

Author

Heully, Jean-Louis, Poteau, Romuald, Berasaluce, Sandra, and Alary, Fabienne

Subjects
MOLECULES, SPECTRUM analysis, PHASE transitions, CHEMICAL structure
Abstract

The new method, called effective group potential, which generalizes the concept of effective core potential by including in a potential the effects of many atoms ligand, is used to calculate transition energies. Three molecules containing a metal atom (Cu, Cr, Ni) surrounded by NH[sub 3] ligands have been studied. It is shown that by replacing the NH[sub 3] group by an effective group potential, the characteristic transitions energies are very well reproduced at various ab initio levels. The transitions studied are transitions between open shells on the metallic center but also ligand to metal transitions where, though unexpected, quite reliable results were also obtained. This method is thus very well suited for the study of the spectrum of a large molecule under the condition that a separation between an active part plus some spectator groups can be made, a condition satisfied in most organometallic molecules as well as in biological molecules. [ABSTRACT FROM AUTHOR]

Published
2002
Full Text
View/download PDF

33. Theoretical investigation on the photophysical properties of model ruthenium complexes with diazabutadiene ligands [[Ru[(bpy).sub.3-x][(dab).sub.x]].sup.2+] (x = 1-3)

Author

Guillon, Thomas, Boggio-Pasqua, Martial, Alary, Fabienne, Heully, Jean-Louis, Lebon, Emilie, Sutra, Pierre, and Igau, Alain

Subjects
Butadiene -- Chemical properties, Butadiene -- Optical properties, Charge transfer -- Analysis, Density functionals -- Usage, Organometallic compounds -- Structure, Organometallic compounds -- Chemical properties, Organometallic compounds -- Electric properties, Ruthenium -- Chemical properties, Ruthenium -- Optical properties, Chemistry
Published
2010

34. Theoretical characterization of the lowest triplet excited states of the tris-(1,4,5,8-tetraazaohenanthrene) ruthenium dication complex

Author

Alary, Fabienne, Boggio-Pasqua, Martial, Heully, Jean-Louis, Marsden, Colin J., and Vicendo, Patricia

Subjects
Charge transfer -- Analysis, Density functionals -- Usage, Excited state chemistry -- Research, Organometallic compounds -- Chemical properties, Organometallic compounds -- Atomic properties, Ruthenium -- Chemical properties, Chemistry
Abstract

The ground and the lowest triplet excited states of the tris-(1,4,5,8-tetraazaphenanthrene) ruthenium complex [[Ru[(tap).sub.3]].sup.2+] are studied. The electronic structures of the metal-to-ligand charge-transfer states (MLCT) and metal-centered (MC) triplet states are discussed by using density functional theory (DFT) and the MLCT-MC equilibrium is examined.

Published
2008

38. Calculation of the ground and excited stats of a mixed valence compound [Fe2(OH)3(NH3)6](super 2+): a class II or class III compound

Author

Carissan, Yannick, Heully, Jean-Louis, Alary, Fabienne, and Daudey, Jean-Pierre

Subjects
Chemical compounds -- Analysis, Iron compounds -- Analysis, Molecular structure -- Analysis, Chemistry
Abstract

The effective group potentials (EGP) approach is used for the computation of the ground and excited state energies of the mixed valence compound. It is the first time that for a system as big as the complex presented above, the ground and excited states are computed with their own orbitals and studied in such a detailed way.

Published
2004

39. Modeling a carbonyl group taking into account back-donation effects through the effective group potential method

Author

Bessac, Fabienne, Alary, Fabienne, Poteau, Romuald, Heully, Jean-Louis, and Daudey, Jean-Pierre

Subjects
Quantum chemistry -- Research, Carbonyl compounds -- Research, Chemicals, plastics and rubber industries
Abstract

Quantum chemical calculations are carried out at different levels of theory to verify the validity of an effective group pseudopotential (EGP) for carbonyl. Three pseudocarbonyl groups, extracted from different systems are discussed, and two are produced from the isolated carbonyl molecule and the other from BH3CO.

Published
2003

40. Effective group potentials. 2. Extraction and transferability for chemical groups involved in covalent or donor-acceptor bonds

Author

Poteau, Romuald, Alary, Fabienne, Makarim, Hassna Abou El, Heully, Jean-Louis, Barthelat, Jean-Claude, and Daudey, Jean-Pierre

Subjects
Chemical bonds -- Observations, Quantum theory -- Research, Chemicals, plastics and rubber industries
Abstract

The effective group potential (EGP) methodology allows one to reduce the number of electrons and nuclei explicitly implied in an ab initio calculation. EGP scheme could be integrated to QM/MM methods to resolve lack of static interactions and the problem of frontier bonds in hybrid methods.

Published
2001

41. Effective group potentials. 1. Method

Author

Poteau, Romuald, Ortega, Ivan, Alary, Fabienne, Solis, Alejandro Ramirez, Barthelat, Jean-Claude, and Daudey, Jean-Pierre

Subjects
Molecular dynamics -- Research, Valence -- Research, Ligands -- Research, Chemicals, plastics and rubber industries
Abstract

Effective group potentials (EGP) are aimed at simplifying molecular ab initio calculations for large systems involving bulky ligands, as long as these ligands are supposed to play the role of spectator groups. The most important step is the definition of modified valence pseudo-orbitals (MVPO), which plays the same role as valence pseudo-orbitals in the derivation of EGP.

Published
2001

48. Theoretical illumination of highly original photoreactive 3MC states and the mechanism of the photochemistry of Ru(ii) tris(bidentate) complexes.

Author

Dixon, Isabelle M., Heully, Jean-Louis, Alary, Fabienne, and Elliott, Paul I. P.

Abstract

We have identified highly novel photoreactive 3MC states of ruthenium(ii) 4,4′-bi-1,2,3-triazolyl (btz) complexes of the form [Ru(N^N)(btz)2]2+ and have elucidated the mechanism of the highly unusual experimental observations of photochemical ligand dechelation and concomitant ligand rearrangement reactivity to form unusual photoproducts trans-[Ru(N^N)(κ2-btz)(κ1-btz)(solvent)]2+. The triplet metal-to-ligand charge-transfer (3MLCT) states and classical Jahn–Teller type triplet metal-centred (3MC) states of the series of complexes [Ru(N^N)3−n(btz)n]2+ (btz = 4,4′-bi-1,2,3-triazolyl; N^N = 2,2′-bipyridyl (bpy), n = 0 (1), 1 (2), 2 (3), 3 (5); N^N = 4-(pyrid-2-yl)-1,2,3-triazole (pytz), n = 1 (4)) have been optimised by density functional theory (DFT) and characterised. There is a gradual and significant destabilisation of the 3MLCT states as the triazole content of the complexes increases, which occurs with a slight stabilisation of the 3MC states. Whilst consistent with the promotion of photochemical reactivity in the heteroleptic complexes of the series relative to 1, these classical 3MC states fail to account for the extraordinary ligand rearrangement processes that accompany ligand ejection. Thorough theoretical exploration of the lowest excited triplet potential energy surface (3PES) here reveals the existence of a new type of 3MC state and the role it plays in the photochemical reactivity of the complexes. This newly discovered state, called MC(F), displays a flattened geometry (indicated by the ‘F’ in the parentheses) which makes it clearly on the path to achieving the coplanarity of the bidentate ligands in the experimentally observed trans-photoproduct. Further novel ‘pentacoordinate’3MC states with coplanar bidentate ligands, called MC(P) (where the ‘P’ in the parentheses denotes the pentacoordinate character), were then identified and optimised. The energy barriers between the different triplet states were confirmed to be small which makes all triplet states accessible. Solvent trapping, which occurs on the singlet PES according to Wigner's rules, is finally achieved by a singlet pentacoordinate species to yield the monosolvento photoproduct. Thus, our calculations not only reveal highly novel 3MC states but more significantly demonstrate their crucial role in the formation of the experimentally observed photoproducts. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

49. A Theoretical Study of the N to O Linkage Photoisomerization Efficiency in a Series of Ruthenium Mononitrosyl Complexes.

Author

García, Juan Sanz, Talotta, Francesco, Alary, Fabienne, Dixon, Isabelle M., Heully, Jean-Louis, and Boggio-Pasqua, Martial

Subjects
RUTHENIUM compound synthesis, RUTHENIUM, PHOTOISOMERIZATION, ISOMERIZATION, DENSITY functional theory
Abstract

Ruthenium nitrosyl complexes are fascinating versatile photoactive molecules that can either undergo NO linkage photoisomerization or NO photorelease. The photochromic response of three ruthenium mononitrosyl complexes, trans-[RuCl(NO)(py)4]2+, trans-[RuBr(NO)(py)4]2+, and trans-(Cl,Cl)[RuCl2(NO)(tpy)]+, has been investigated using density functional theory and time-dependent density functional theory. The N to O photoisomerization pathways and absorption properties of the various stable and metastable species have been computed, providing a simple rationalization of the photoconversion trend in this series of complexes. The dramatic decrease of the N to O photoisomerization efficiency going from the first to the last complex is mainly attributed to an increase of the photoproduct absorption at the irradiation wavelength, rather than a change in the photoisomerization pathways. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results