Search results for "photophysic"
showing 9 items of 39 documents
Synthesis of oligomers and polymers doped with porphyrins for solar energy conversion
2017
The aim of this thesis was to elaborate new electron donor materials for organic solarcells. This emerging photovoltaic technology is rapidly expanding, and has yet already reached the limit for its large-scale commercialization. The low manufacturing cost of organic photovoltaic devices make then competitive face to well-established inorganic technologies. Their biggest advantage is their weight and their mechanical properties which make them flexible. They should play a key role in future as a complement to classic solar cells, with their use in specific applications. We developed polymers by using different chomophores, well-known for their interesting photophysical properties: the porph…
Excited State N−H Tautomer Selectivity in the Singlet Energy Transfer of a Zinc(II)-Porphyrin-Truxene-Corrole Assembly
2017
International audience; An original corrole-containing polyad for S-1 energy transfer, in which one zinc(II)-porphyrin donor is linked to two free-base corrole acceptors by a truxene linker, is reported. This polyad exhibits a rapid zinc(II)-porphyrin*free-base corrole transfer (4.83x10(10)s(-1); 298K), even faster than the tautomerization in the excited state processes taking advantage of the good electronic communication provided by the truxene bridge. Importantly, the energy transfer process shows approximately 3-fold selectivity for one corrole N-H tautomer over the other even at low temperature (77K). This selectivity is due to the difference in the J-integral being effective in both t…
Green-Light Activation of Push-Pull Ruthenium(II) Complexes.
2020
Abstract Synthesis, characterization, electrochemistry, and photophysics of homo‐ and heteroleptic ruthenium(II) complexes [Ru(cpmp)2]2+ (22+) and [Ru(cpmp)(ddpd)]2+ (32+) bearing the tridentate ligands 6,2’’‐carboxypyridyl‐2,2’‐methylamine‐pyridyl‐pyridine (cpmp) and N,N’‐dimethyl‐N,N’‐dipyridin‐2‐ylpyridine‐2,6‐diamine (ddpd) are reported. The complexes possess one (32+) or two (22+) electron‐deficient dipyridyl ketone fragments as electron‐accepting sites enabling intraligand charge transfer (ILCT), ligand‐to‐ligand charge transfer (LL'CT) and low‐energy metal‐to‐ligand charge transfer (MLCT) absorptions. The latter peak around 544 nm (green light). Complex 22+ shows 3MLCT phosphorescenc…
Origin of the large spectral shift in electroluminescence in a blue light emitting cationic iridium(III) complex
2007
A new, but archetypal compound [ Ir( ppy- F-2) (2)Me(4)phen] PF6, where ppy- F2 is 2-(2',4'- fluorophenyl) pyridine and Me(4)phen is 3,4,7,8- tetramethyl- 1,10- phenanthroline, was synthesized and used to prepare a solid-state light-emitting electrochemical cell (LEEC). This complex emits blue light with a maximum at 476 nm when photoexcited in a thin film, with a photoluminescence quantum yield of 52%. It yields an efficient single-component solid-state electroluminescence device with a current efficiency reaching 5.5 cd A(-1) and a maximum power efficiency of 5.8 Lm Watt(-1). However, the electroluminescence spectrum is shifted with respect to the photoluminescence spectrum by 80 nm resul…
A theoretical study of the intramolecular charge transfer in 4-(dimethylamino)benzethyne
2014
We have investigated the non-adiabatic relaxation processes occurring in the singlet manifold of 4-(dimethylamino)benzethyne (DMABE){,} a molecule isoelectronic with 4-(dimethylamino)benzonitrile (DMABN) but lacking its characteristic dual fluorescence{,} using multireference perturbation theory methods. The results obtained point out to the existence of a two-fold decay mechanism in which the population of the initially accessed La state bifurcates towards a locally excited (LE) and a [small pi][sigma]* state. Further relaxation to an emitting intramolecular charge transfer (ICT) state is impeded due to the presence of pronounced energy barriers along their associated potential energy surf…
Synthesis, structure and photophysical properties of a highly luminescent terpyridine-diphenylacetylene hybrid fluorophore and its metal complexes
2014
A new fluorescent terpyridyl-diphenylacetylene hybrid fluorophore 4'-[4-{(4-methoxyphenyl)ethynyl}phenyl]-2,2':6',2''-terpyridine, L, was synthesized via Sonogashira cross-coupling of 4'-(4-bromophenyl)-2,2':6',2''-terpyridine and 4-ethynylanisole in the presence of Pd(PPh3)4/CuI as a catalyst. The solid state structure of L shows a trans arrangement of pyridine nitrogen atoms along the interannular bond in the terpyridine domain. Five transition metal complexes of L, {[FeL2](CF3SO3)2 (1), [ZnL2](ClO4)2 (2), [CdL2](ClO4)2 (3), [RuL2](PF6)2 (4), and PtMe3IL (5)}, have also been synthesized and characterized by spectroscopic methods and single crystal X-ray analysis. The X-ray crystal structu…
Synthesis, structure and photophysical properties of a highly luminescent terpyridine-diphenylacetylene hybrid fluorophore and its metal complexes
2015
A new fluorescent terpyridyl-diphenylacetylene hybrid fluorophore 4′-[4-{(4-methoxyphenyl)ethynyl}phenyl]-2,2′:6′,2′′-terpyridine, L, was synthesized via Sonogashira cross-coupling of 4′-(4-bromophenyl)-2,2′:6′,2′′-terpyridine and 4-ethynylanisole in the presence of Pd(PPh3)4/CuI as a catalyst. The solid state structure of L shows a trans arrangement of pyridine nitrogen atoms along the interannular bond in the terpyridine domain. Five transition metal complexes of L, {[FeL2](CF3SO3)2 (1), [ZnL2](ClO4)2 (2), [CdL2](ClO4)2 (3), [RuL2](PF6)2 (4), and PtMe3IL (5)}, have also been synthesized and characterized by spectroscopic methods and single crystal X-ray analysis. The X-ray crystal structu…
Applications of Quantum Chemistry in Spectroscopy: Molecules, Complexes of Van der Waals, trapped Molecules
2009
I described in this memory my activities as a researcher at Tomsk well before 2003, in succession to the State University of Tomsk in the Faculty of Physics, Institute of Physics of Siberia, and the Institute of 'Atmospheric Optics, in France since then, mostly at the University of Bourgogne (ICB), but also at the University of Lille I (PhLAM) and the University of Marne-la-Vallée (LCT). Part of my work has been dedicated to the evaluation by calculating ab initio of rovibrational constants for quasi-spherical molecules. The centrifugal distortion constants and the dipole moment of the molecule SO2F2 were calculated to validate the tensor theory and interpreter the spectrum. I twas shown th…
The Impact of a 1,2,3-Triazole Motif on the Photophysical Behavior of Non-K Tetrasubstituted Pyrene with a Substitution Pattern Providing the Long Ax…
2022
1,3,6,8-Tetrasubstituted pyrene derivatives with two types of substituents (4-(2,2-dimethylpropyloxy)pyridine, 1-decyl-1,2,3-triazole, 1-benzyl-1,2,3-triazole, and pyrazole), substituted in such a way that provides the long axial symmetry, are prepared and characterized in the present study. To the best of our knowledge, the pyrene derivative containing the same heteroaryl motif (triazole) but substituted by two various alkyls, straight decyl and benzyl-based side chains (C), is reported for the first time. For comparison, compounds with one kind of triazole motif and substituted pyridine or pyrazole groups were prepared (A and B). The photophysical properties of all molecules were evaluate…