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Phosphorescent platinum(ii) complexes were introduced site-specifically into DNA oligonucleotides. The resulting bioconjugates may be applied as bio-compatible oxygen sensors.

Fluoride is a natural contaminant of water – that endangers many people worldwide when present in concentrations higher than 2 ppm. Here, fluoride removal by four different nanostructured colloidal particles (SiO2@ZrO2nc, SiO2@ZrO2c, @ZrO2nc, and @ZrO2c) was measured in batch systems within a period of 24 h. Surprisingly, these materials removed fluoride from the water solutions and reached equilibrium in less than 10 min. The combination of high specific surface and fast fluoride removal placed these materials among the top materials currently known in fluoride removal. Also, the impact of element leaching was measured and quantified. The influence of time, pH, and fluoride concentration on leaching of Zr and Si was evaluated with a response surface methodology. Leaching of Zr and Si continued for several hours and depended on first-order, quadratic and cross-product coefficients. Previous studies of fluoride removal with zirconium oxide often assumed that a decrease in fluoride concentration in the solution indicated that fluoride was bound to the surface of the oxide. Zirconium oxide's solubility in water is low, but not zero. Hence, Zr might have formed soluble fluorocomplexes. This is the first report of fluoride removal with zirconium oxide that studied the leaching of the solid to exclude the formation of soluble fluorocomplexes.

A full understanding concerning the photophysical properties of a fluorescent label is crucial for a reliable and predictable performance in biolabelling applications. This holds true not only for the choice of a fluorophore in general, but also for the correct interpretation of data, considering the complexity of biological environments. In the frame of a case study involving inflammation imaging, we report the photophysical characterization of four fluorescent S100A9-targeting compounds in terms of UV–vis absorption and photoluminescence spectroscopy, fluorescence quantum yields (ΦF) and excited state lifetimes (τ) as well as the evaluation of the radiative and non-radiative rate constants (kr and knr, respectively). The probes were synthesized based on a 2-amino benzimidazole-based lead structure in combination with commercially available dyes, covering a broad color range from green (6-FAM) over orange (BODIPY-TMR) to red (BODIPY-TR) and near-infrared (Cy5.5) emission. The effect of conjugation with the targeting structure was addressed by comparison of the probes with their corresponding dye-azide precursors. Additionally, the 6-FAM and Cy5.5 probes were measured in the presence of murine S100A9 to determine whether protein binding influences their photophysical properties. An interesting rise in ΦF upon binding of 6-FAM-SST177 to murine S100A9 enabled the determination of its dissociation equilibrium constant, reaching up to KD = 324 nM. This result gives an outlook for potential applications of our compounds in S100A9 inflammation imaging and fluorescence assay developments. With respect to the other dyes, this study demonstrates how diverse microenvironmental factors can severely impair their performance while rendering them poor performers in biological media, showing that a preliminary photophysical screening is key to assess the suitability of a particular luminophore.

A family of Pt(II) complexes bearing monoanionic C^N^N ligands as luminophoric units as well as a set of monodentate ligands derived from allenylidene and carbene species were synthesized and characterized in terms of structure and photophysical properties. In addition, we present the extraordinary molecular structure of a phosphorescent complex carrying an allenylidene ligand. Depending on the co-ligand, an effect can be observed in the photoluminescence lifetimes and quantum yields as well as in the radiative and radiation less deactivation rate constants. Their correlation with the substitution pattern was analyzed by comparing the photoluminescence in fluid solution at room temperature and in frozen glassy matrices at 77 K. Moreover, in order to gain a deeper understanding of the electronic states responsible for the optical properties, density functional theory calculations were performed. Finally, the cytotoxicity of the complexes was evaluated

A series of Pd(ii) and Pt(ii) complexes bearing tetradentate ligands as dianionic luminophores were synthesized and their room-temperature photoluminescence in PMMA films as well as in mechanochromic crystalline phases was correlated with molecular structure.

A selective synthesis of relevant fluorescent compounds, indolizino[3,4,5-ab]isoindoles (INIs), through a Mn(i)-catalyzed C–H activation on readily available 2-phenylpyridines is described.

Two isoleptic complexes involving Pd(II) and Pt(II) centres with a tetradentate luminophoric ligand were adsorbed onto Laponite (LAP), yielding H2O-dispersible nanohybrids with remarkable photoexcited state properties. The adsorption promoted rigidification of the coordination compounds and suppression of roto-vibrational deactivation pathways, thus enhancing the performance of the molecular species. Interestingly, room temperature phosphorescence was achieved in the case of the Pd(II)-containing nanohybrid along with a marked 3O2 sensitivity, whereas the photoluminescence of the Pt(II)-based material showed only a mild dependence on the presence of 3O2 while reaching up to 37% quantum yield.

In this contribution, we report on a class of emitters based on bridged oxo‐ and/or thioethers revealing striking photoluminescence properties in fluid solution and in the solid state. In total, nine compounds were investigated concerning their photophysical properties, which were interpreted by quantum chemical calculations. To our delight, we discovered compounds possessing nearly identical photoluminescence quantum yields (Φ F) in solution and in the solid state, which has been rarely reported so far. Besides these efforts, we shed light on the influence of polymorphism and solvent polarity on the emission properties. In addition, an in‐depth X‐ray diffractometric analysis was conducted to correlate molecular packing in the crystal with differences in the photophysical properties., A highly emissive system based on bridged aromatic oxo‐ and/or thioethers is implemented. These compounds reveal striking emission properties in the solid state as well as in fluid solutions. Furthermore, solvatochromism as well as polymorphism were observed and the structure‐property relationship within a library of nine different compounds was assessed.

The C-C bond formation reaction represents a fundamental and important transformation in synthetic chemistry, and exploring new types of C-C bond formation reactions is recognized as appealing, yet challenging. Herein, we disclose the first example of rhodium-catalyzed dealkenylative arylation of alkenes with arylboronic compounds, thereby providing an unconventional access to bi(hetero)aryls with excellent chemo-selectivity. In this method, C(aryl)-C(alkenyl) and C(alkenyl)-C(alkenyl) bonds in various alkenes and 1,3-dienes can be cleaved via a hydrometalation and followed by beta-carbon elimination pathway for Suzuki-Miyaura reaction. Furthermore, a series of novel organic fluorescent molecules with excellent photophysical properties has been efficiently constructed with this protocol.

Efficient shielding of phosphorescent transition metal complexes against diffusion-controlled collisional quenching by triplet molecular dioxygen as well as reduction of microenvironment-related ra...

Herein, we exploit coordination geometry as a new tool to regulate the non-covalent interactions, photophysical properties and energy landscape of supramolecular polymers. To this end, we have designed two self-assembled Pt(II) complexes 1 and 2 that feature an identical aromatic surface, but differ in the coordination and molecular geometry as a result of judicious ligand choice. Even though both complexes form cooperative supramolecular polymers in methylcyclohexane, their supramolecular and photophysical behaviour differ significantly: while the high preorganization of the bipyridine-based complex 1 enables an H-type 1D stacking with short Pt/Pt contacts via a two-step consecutive process, the existence of increased steric effects for the pyridyl-based derivative 2 hinders the formation of metal–metal contacts and induces a single aggregation process into large bundles of fibers. Ultimately, this fine control of Pt/Pt distances leads to tuneable luminescence—red for 1 vs. blue for 2, which highlights the relevance of coordination geometry., In diesem Beitrag nutzen wir die Koordinationsgeometrie als neues Instrument zur Regulierung der nicht-kovalenten Wechselwirkungen, der photophysikalischen Eigenschaften und der Energielandschaft von supramolekularen Polymeren. Zu diesem Zweck haben wir zwei selbstorganisierte Pt(II)-Komplexe 1 und 2 entwickelt, die eine identische aromatische Oberfläche aufweisen, sich aber durch die Wahl des Liganden in ihrer Koordinations- und Molekülgeometrie unterscheiden. Obwohl beide Komplexe kooperative supramolekulare Polymere in Methylcyclohexan bilden, unterscheiden sie sich in ihrem Verhalten deutlich: Während die hohe Vororganisation des auf Bipyridin basierenden Komplexes 1 eine 1D-Stapelung vom H-Typ mit kurzen Pt/Pt-Kontakten über einen zweistufigen, konsekutiven Prozess ermöglicht, verhindert das Vorhandensein von verstärkten sterischen Effekten beim auf Pyridyl basierenden Derivat 2 die Bildung von Metall-Metall-Kontakten und induziert einen einzigen Aggregationsprozess zu großen Faserbündeln. Letztlich führt diese Feinsteuerung der Pt/Pt-Abstände zu einer einstellbaren Lumineszenz - rot für 1 und blau für 2 -, was die Bedeutung der Koordinationsgeometrie unterstreicht.

The synthesis, photophysical characterization, and quantum chemical calculations of a series of benzotriazinyl radicals and their styryl radical trapping products are presented. The benzotriazinyl radicals are non-luminescent but surprisingly the corresponding styryl radical trapping products exhibit high fluorescence quantum yields (up to 60% in some cases), making them highly valuable probes or labels. Additionally, the influence of the substitution pattern on the optical properties of the radical trapping products was observed experimentally and interpreted by means of quantum chemical calculations. Specific substitution patterns showed a bathochromic shift compared to the unsubstituted compound. Computationally, it was shown that this substitution pattern leads to a stronger energetic stabilization of the lowest unoccupied molecular orbital than the highest occupied molecular orbital. Analysis of the influence of the substitution pattern on the optical properties showed a bathochromic shift in several examples, which was interpreted by means of quantum chemical calculations.

In this work, a series of γ-substituted diphenylnaphthalonitriles were synthesized and characterized. They show efficient emission in solution and in the aggregated state and their environment responsiveness is based on having variable substituents at the para-position of the two phenyl moieties. The excited state properties were fully investigated in tetrahydrofuran (THF) solutions and in THF/H2O mixtures. The size of the aggregates in aqueous media were measured by dynamic light scattering (DLS). The steady-state and time-resolved photoluminescence spectroscopy studies revealed that all the molecules show intense fluorescence both in solution and in the aggregated state. In THF solutions, a blue emission was observed for the unsubstituted (H), methyl- (Me) and tert-butyl- (t-Bu) substituted γ-diphenylnaphthalonitriles, which can be attributed to a weak π-donor capability of these groups. On the other hand, the methoxy- (OMe), methylsulfanyl- (SMe) and dimethylamino- (NMe2) substituted compounds exhibit a progressive red-shift in emission compared to H, Me and t-Bu due to a growing π-electron donating capability. Interestingly, upon aggregation in water-containing media, H, Me and t-Bu show a slight red-shift of the emission and a blue-shift is observed for OMe, SMe and NMe2. The crystal structure of Me allowed a detailed discussion of the structure–property relationship. Clearly, N-containing substituents such as NMe2 possess more electron-donating ability than the S-based moieties such as SMe. Moreover, it was found that NMe2 showed higher luminescence quantum yields (ΦF) in comparison to SMe, indicating that N-substituted groups could enhance the fluorescence intensity. Therefore, the π-donor nature of the substituents on the phenyl ring constitutes the main parameter that influences the photophysical properties, such as excited state lifetimes and photoluminescence quantum yields. Hence, a series of highly luminescent materials from deep blue to red emission depending on substitution and environment is reported with potential applications in sensing, bioimaging and optoelectronics.

In this work, we explored coordination compounds featuring caffeine-based carbene co-ligands and tridentate dianionic pincer luminophores derived from 2,6-bis(1H-1,2,4-triazol-5-yl)pyridine (N), as well as from 2-phenyl-6-(1H-1,2,4-triazol-5-yl)pyridine (C), bearing either Ad (adamantyl) or tBu (tertiary butyl) substituents. The new 2-phenyl-6-(1H-1,2,4-triazol-5-yl)pyridine-based ligand precursors along with four Pt(II) complexes, namely Pt(C-tBu), Pt(C-Ad), Pt(N-tBu) and Pt(N-Ad) were characterized. Further on, the influence of the different substituents at the chelating luminophores and of the caffeine-based NHC-co-ligand on the photophysical properties (including photoluminescence quantum yields (Φ

In this work, we synthesized two tailored phosphorescent Pt(II) complexes bearing a cyclometalating tridentate thiazole-based C^N*N pincer luminophore (L) and exchangeable chlorido ([PtCl(L)]) or c...

Small‐molecule probes for the in vitro imaging of KCa3.1 channel‐expressing cells were developed. Senicapoc, showing high affinity and selectivity for the KCa3.1 channels, was chosen as the targeting component. BODIPY dyes 15–20 were synthesized and connected by a CuI‐catalyzed azide–alkyne [3+2]cycloaddition with propargyl ether senicapoc derivative 8, yielding fluorescently labeled ligands 21–26. The dimethylpyrrole‐based imaging probes 25 and 26 allow staining of KCa3.1 channels in NSCLC cells. The specificity was shown by removing the punctate staining pattern by pre‐incubation with senicapoc. The density of KCa3.1 channels detected with 25 and by immunostaining was identical. The punctate structure of the labeled channels could also be observed in living cells. Molecular modeling showed binding of the senicapoc‐targeting component towards the binding site within the ion channel and orientation of the linker with the dye along the inner surface of the ion channel., Imaging channels: Small‐molecule probes for the in vitro imaging of KCa3.1 channel‐expressing cells were designed and developed. Using senicapoc as the targeting component, the BODIPY‐labeled probes could selectively stain the channels in living cells and the channel punctate structure could be observed.

Tuning the room-temperature photoluminescence over the whole visible spectrum towards white light emission based on purely organic dual emitters has not been reported yet. In this contribution, we mapped the entire visible range of the electromagnetic spectrum (from violet to red) and even achieved white light emission (CIE: 0.31, 0.34) by combining the intrinsic ns-fluorescence with ultralong ms-phosphorescence from purely organic dual emitters. Hence, we realized small molecular materials showing high photoluminescence quantum yields in the solid state at room temperature, which was achieved by active exploration of the regioisomeric substitution space. Chromophore stacking-supported stabilization of triplet excitons with assistance from enhanced intersystem crossing channels in the neat crystalline state was found to play the primary role for the ultra-long phosphorescence. The present study includes two main advancements: firstly, it provides an easy strategy to cover the entire visible spectrum, based on organic phosphorescent emitters with versatile regioisomeric substitution patterns. Secondly, this study provides a single molecular source of white light with a strikingly long lifetime (up to 163.5 ms) for the phosphorescent component, as well as remarkably high overall photoluminescence quantum yields reaching up to Φ L = 20%. Such features have been rarely reported for purely organic compounds and provide a crucial platform to design the next generation of sustainable luminophores with advanced applications spanning from multimodal bioimaging and sensing to advanced optoelectronics, without the need for scarce elements such as Ru, Os, Rh, Ir, Pd or Pt.

In this work, we describe the synthesis, structural and photophysical characterization of four novel Pd(ii) and Pt(ii) complexes bearing tetradentate luminophoric ligands with high photoluminescence quantum yields (ΦL) and long excited state lifetimes (τ) at room temperature, where the results were interpreted by means of DFT calculations. Incorporation of fluorine atoms into the tetradentate ligand favors aggregation and thereby, a shortened average distance between the metal centers, which provides accessibility to metal–metal-to-ligand charge-transfer (3MMLCT) excimers acting as red-shifted energy traps if compared with the monomeric entities. This supramolecular approach provides an elegant way to enable room-temperature phosphorescence from Pd(ii) complexes, which are otherwise quenched by a thermal population of dissociative states due to a lower ligand field splitting. Encapsulation of these complexes in 100 nm-sized aminated polystyrene nanoparticles enables concentration-controlled aggregation-enhanced dual emission. This phenomenon facilitates the tunability of the absorption and emission colors while providing a rigidified environment supporting an enhanced ΦL up to about 80% and extended τ exceeding 100 μs. Additionally, these nanoarrays constitute rare examples for self-referenced oxygen reporters, since the phosphorescence of the aggregates is insensitive to external influences, whereas the monomeric species drop in luminescence lifetime and intensity with increasing triplet molecular dioxygen concentrations (diffusion-controlled quenching)., Pt(ii) and Pd(ii) complexes with unprecedented photophysical properties were developed. Encapsulation in nanoparticles boosted their performance while rendering them as self-referenced oxygen sensors.

In this work, for the first time, the comparative use of P-, As-, and Sb-based ligands in phosphorescent coordination compounds is reported toward new coordination chemical concepts in the design and realization of tailored triplet emitters with nonconventional elements. By means of spectroscopic, X-ray diffractometric, and quantum-chemical methods, we reconstructed the nature of the chemical bonds as well as the influence of the increasingly heavy elements on the photoexcited state properties, which were correlated with the hybridization and polarizability of the pnictogen atoms (Pn). In particular, we elucidated the structural and photophysical properties of a series of homologous Pt(II) complexes with monodentate ancillary ligands based on group 15 elements, namely P, As, and Sb. Six coordination compounds bearing tridentate dianionic 2,6-bis(1H-1,2,4-triazol-5-yl)pyridine luminophoric pincer ligands bearing either CF3 or tBu moieties on the triazole rings along with triphenylpnictogens (PnPh3) as monodentate ancillary ligands ([CF3/Pn] or [tBu/Pn], respectively) have been investigated. The electron donating or withdrawing effect of the peripheral substituent (tBu vs. CF3, respectively) and its influence on the bonding, crystal packing as well as the excited state energies and lifetimes was assessed in fluid solutions, frozen glassy matrices, amorphous solids, and crystalline phases. A progressively red-shifted phosphorescence was observed with increasing atomic number along with a growing compensation of hybridization defects upon coordination of the Pn atom to the Pt(II) center. The change of molecular geometry of the PnPh3 unit upon complexation was extrapolated to predict the structural and excited state characteristics of the Bi-based analogues, which according to DFT calculations should be stable species and are the subject of ongoing synthetic efforts. In general, we envisage the use of these ligands for the relativistic enhancement of radiative deactivation rate processes, especially if Bi-based s-orbitals participate on the bond with the metal center, paving the road toward novel coordination compounds using abundant elements with high spin-orbit coupling for sustainable electroluminescent devices.

The adsorption of a Re(CO)3(phen)-poly(4-vinylpyridine) polymer, RePVP, on multiwall carbon nanotubes surfaces is studied by transmission electron microscopy and absorption spectroscopy in combination with chemometric techniques in MeOH/H2O solvent mixture. Nanohybrid structures like a shish-kebab (NHSK) are observed by TEM when RePVP is wrapped around carbon nanotubes (CNTs) surfaces. The association between RePVP and CNTs studied by absorption spectroscopy suggests the coexistence of CNTs with a high or low content of adsorbed RePVP on their surface. In the absence of CNTs, the photophysical properties of RePVP (i.e., luminescence quantum yield, ΦL, and amplitude-weighted average lifetimes, ⟨τ⟩) are strongly dependent on the morphology of the polymer as witnessed by the dependence of ΦL on the concentration of RePVP (CRePVP) and the fact that in CH3CN ΦL and ⟨τ⟩ are sensitive to O2 while in a MeOH/H2O solvent mixture they are not. In the NHSK, an energy-transfer process between excited −[Re(CO)3(phen)]+* pendent chromophores and the CNTs surface, with static and dynamic components, is responsible for the quenching of the RePVP luminescence by CNTs. Fil: Maisuls, Iván. Westfälische Wilhelms Universität; Alemania Fil: Ostendorp, Stefan. Westfälische Wilhelms Universität; Alemania Fil: Wilde, Gerhard. Westfälische Wilhelms Universität; Alemania Fil: Parola, A. Jorge. Universidade Nova de Lisboa; Portugal Fil: Strassert, Cristian A.. Westfälische Wilhelms Universität; Alemania Fil: Wolcan, Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina

The development of organic materials with high solid‐state luminescence efficiency is highly desirable because of their fundamental importance and applicability in optoelectronics. Herein, a rapid construction of novel BF2 complexes with N,O‐bidentate ligands by using Cu(BF4)2•6H2O as a catalyst and BF2 source is disclosed, which avoids the need for pre‐composing the N,O‐bidentate ligands and features a broad substrate scope and a high tolerance level for sensitive functional groups. Moreover, molecular oxygen is employed as the terminal oxidant in this transformation. A library of 36 compounds as a new class of BF2 complexes with remarkable photophysical properties is delivered in good to excellent yields, showing a substituent‐dependency on the photophysical properties, derived from the π–π* character of the photoexcited state. In addition, aggregation‐induced emission (AIE) is observed and quantified for the brightest exemplars. The excited state properties are fully investigated in solids and in THF/H2O mixtures. Hence, a new series of photofunctional materials with variable photophysical properties is reported, with potential applications for sensing, bioimaging, and optoelectronics., A novel strategy is developed for the rapid construction of aggregation‐induced emission (AIE) active BF2 complexes with N,O‐bidentate ligands through a copper‐catalyzed cascade C—H activation/acyloxylation and difluoroboronation, which avoids the need for pre‐composing the N,O‐bidentate ligands. A library of 36 compounds as a new class of AIE‐active BF2 complexes with remarkable photophysical properties is delivered in good to excellent yields.

Aggregation-induced emission (AIE) is a rapidly evolving field particularly suited for bioapplications including imaging and sensing. We introduce a water-soluble block copolymer/AIE micelle system, in which we incorporate an aromatic thioether-based fluorophore with AIE properties into an amphiphilic diblock terpolymer via covalent post-modification. For that, we synthesized a series of poly(ethylene oxide)-block-poly(styrene-co-hydroxyethyl methacrylate) (PEO-b-P(S-co-HEMA)) diblock terpolymers by atom transfer radical polymerization featuring a hydrophilic PEO block, and a hydrophobic block of PS statistically segmented with HEMA for covalent fluorophore attachment. Synthetic steps were monitored with NMR and IR spectroscopy, mass spectrometry, and gel permeation chromatography (GPC). Self-assembly of the fluorophore-modified block copolymers in water resulted in micelles with fluorescent properties attributed to the immobilized AIEgen within the micelle core. The micelle morphology was analyzed with transmission electron microscopy (TEM) and dynamic light scattering (DLS), while photophysical properties of polymers and micelles were comprehensively investigated with fluorescence spectroscopy. In perspective, the presented diblock terpolymer can be modified with a range of compatible fluorophores, which allows the direct comparison of fluorophore performance in identical assemblies.

Re(I)--polypyridyl complexes have interesting and distinctive photochemical and photosensitizing properties. This work describes the capability to induce (or photoinduce) DNA damage of three Re(I)-complexes with a naturally occurring alkaloid called norharmane (nHo) as ligand: [Re(CO)₃ (nHo)(L)]CF₃ SO₃ where L=2,2'-bipyridine (ReBpy), phenanthroline (RePhen) or dipyrido[3,2-a:2',3'-c]phenazine (ReDppz). The interaction of the complexes with DNA was investigated by steady-state and time-resolved spectroscopy. Data show that the mode and strength of interaction depend on the chemical structure of the bidentate ligand. The complexes show a major static contribution to the overall interaction, giving rise to the formation of noncovalent adducts with DNA, and the particular trend observed was RePhen>ReDppz>ReBpy. Photo-oxidation at the purine bases represents the major DNA damaging mechanism. RePhen also induces single-strand breaks in a yield similar to that of base damage, suggesting an additional photosensitizing pathway. We also performed the Ames test to evaluate the cytotoxic and mutagenic properties of both non-irradiated and photoexcited complexes. RePhen, but not the other complexes, turned out to be both toxic and phototoxic for the bacteria., Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas, Centro de Investigaciones Ópticas

The photochemical and photophysical properties of [(nHo)Re(CO)3(L)]+ complexes, where nHo = 9H-pyrido[3,4-b]indole and L = 2,2′ bipyridine (bpy), 1,10 phenantroline (phen) or dipyridil[3,2-a:2′3′-c]phenazine (dppz) were investigated by Laser Flash Photolysis (LFF) and Pulse Radiolysis (PR) techniques. While complexes with L = bpy or phen show absorption transients compatible with MLCTRe→L excited states, [(nHo)Re(CO)3(dppz)]+ showed an excited state assignable to a dppz-centered, 3ππ*dppz. In aqueous solutions, the last complex does not generate any absorption transient. However, when Calf thymus DNA was added, the same absorption spectrum was obtained. These results suggest that this complex can intercalate into DNA. The species generated in either reductive or oxidative conditions in LFF experiments were compared with those obtained in PR. Also, the quenching rate constants (kq) of the excited states with MV2+ were calculated. The intercalation of the [(nHo)Re(CO)3(dppz)]+ into DNA, increases kq ∼100 times. This result is rationalized in terms of the conditions created by the intercalation using the biopolymer as a well-organized matrix., Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas

A new polymer, P4VP-Re(dppz), based on the poly-4-vinylpyridine structure containing Re(CO)3(dppz)⁺ pendants was synthesized. Multiple morphologies of P4VP-Re(dppz), such as vesicles, spherical nanoaggregates, large vesicle compounds, rings and pyramidal structures were observed by AFM and TEM in cast films of P4VP-Re(dppz) in solvents of different polarity and solvent/acid mixtures. Several conformations of a model monomer of P4VP-Re(dppz) were studied by TD-DFT to ascertain the effect of protonation over the molecular structure as well as over the absorption spectroscopy of P4VP-Re(dppz). P4VP-Re(dppz) excited states and their redox reactivity towards the sacrificial reductant TEOA were studied by flash photolysis experiments either in DMF and in DMF/HClO4. Those experiments were compared to the ones derived from thermal reactions of P4VP-Re(dppz) with solvated electrons in pulse radiolysis experiments. All the photophysical and photochemical properties studied were rationalized in terms of an interplay between 3IL(ππ*), 3MLCT(phz) and the 3MLCT(phen) states., Facultad de Ciencias Exactas, Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas, Facultad de Ingeniería

Two β-carboline rhenium(I) complexes, fac-[Re(CO)3(dppz)(nHo)]O3SCF3 and fac-[Re(CO)3(nHo)2Cl] where dppz=dipyrido[3, 2-a:2′,3′-c] phenazine and nHo=9H-pyrido[3, 4-b]indole (norharmane), have been synthesized. These complexes were fully characterized by structural X-ray diffraction, 1H and 13C NMR, UV-vis absorption and FT-IR spectroscopy and mass spectrometry. Ground state geometry optimization was carried out in vacuo with the PBE0 hybrid functional using the LanL2DZ basis set. The characterization was complemented with TD-DFT calculations using several hybrid functionals. Cellular uptake and cytotoxic effect of both complexes against human lung carcinoma (A549) cells were evaluated. For comparative purpose, two related fac-[Re(CO)3(L)(nHo)]+ complexes (L=bpy and phen) were included in the biological studies. The anti-proliferative effect of the compounds was rationalized in terms of the different extension of the ligands π-system. Fil: Maisuls, Iván. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina Fil: Wolcan, Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina Fil: Piro, Oscar Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina Fil: Castellano, Eduardo E.. Instituto de Física de São Carlos; Brasil Fil: Petroselli, Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; Argentina Fil: Erra Balsells, Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; Argentina Fil: Cabrerizo, Franco Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina Fil: Ruiz, Gustavo Teodosio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina

Two novel Re(I) complexes with the general formula fac-[Re(CO)3(L)(nHo)]CF33SO3, where L = 2,2’-bipyridine (bpy) or 1,10 phenanthroline (phen) and nHo (9H-pyrido[3,4-b]indole; norharmane) have been synthesized. The Re(I)–nHo complexes were characterized by structural X-ray diffraction, 1H and 13C NMR, UV-vis absorption and FT-IR spectroscopy, and by a combination of two mass spectrometry techniques, namely ESI-MS and UV-MALDI-MS. All characterizations showed that nHo is coordinated to the metal atom by the pyridine nitrogen of the molecule. X-ray structural analysis revealed that the crystal lattices for both complexes are further stabilized by a strong >N–H⋯O bond between the pyrrole NH group of the pyridoindole ligand and one oxygen atom of the trifluoromethanesulfonate counter-ion. Ground state geometry optimization by DFT calculations showed that in fluid solution the nHo ligand may rotate freely. The nature of the electronic transitions of Re(CO)3(bpy)(nHo)⁺ were established by TD-DFT calculations. The set of the most important electronic transitions present in this complex are comprised of π → π* electronic transitions centered on bpy and nHo moieties, LLCTnHo→COs, MLLCTRe(CO)3→bpy and LLCTnHo→bpy transitions. Additionally, TD-DFT calculations predict the existence of another two intense MLLCTRe(CO)3→nHo electronic transitions. Calculated UV-vis absorption spectra are in good agreement with the corresponding experimental data for the bpy-containing complex., Facultad de Ciencias Exactas, Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas, Instituto de Física La Plata

Spherical particles with an amorphous core of silica and a crystalline shell of titanium oxide (SiO2@TiO2) formed in a three-step procedure, being the last step a mild chemical treatment. SiO2@TiO2 had a shell with pores (micro and mesopores) permeating between TiO2 nanocrystals (anatase) and a solid core of amorphous silica. The spheres had an outstanding specific surface area (300m2g-1). A cyto- and genotoxic study of SiO2@TiO2 and titanium oxide nanoparticles (TiO2-NP) on UMR106 cells with 24h exposure showed that SiO2@TiO2 colloidal particles were less toxic than TiO2-NP. Fil: Di Virgilio, Ana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina Fil: Maisuls, Iván. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina Fil: Kleitz, Freddy. Laval University; Canadá Fil: Arnal, Pablo Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; Argentina