Laboratoire Of Chimie Organique Et Spectroscopies Avancees Lcosa

Strasbourg, France

Laboratoire Of Chimie Organique Et Spectroscopies Avancees Lcosa

Strasbourg, France

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Dubuisson E.,CNRS Neel Institute | Dubuisson E.,Ecole Polytechnique - Palaiseau | Badre S.,Ecole Normale Superieure de Cachan | Gautier Luneau I.,CNRS Neel Institute | And 4 more authors.
Dyes and Pigments | Year: 2013

We present the synthesis of 2,6-diethyl-4,4-difluoro-8-(-4-iodophenyl)-1,3, 5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene labeled as iodophenyl-BODIPY (IP-BDPY) and the growth of microcrystals or spherulitic crystal plates in typical free solutions. Their crystal structures, the absorption and fluorescence spectroscopies were investigated. Relations between crystal structure and absorption, dichroism and fluorescence properties were established. The first results obtained for the preparation of IP-BDPY nanocrystals grown in sol-gel thin films were also introduced. Their absorption and fluorescence spectra were compared with the spectra of the corresponding bulk crystal and diaplectic amorphous solid obtained by a drastic crushing. Unexpected results were obtained: amorphization of molecular nanocrystals just after their growth by capillary forces generated during the drying of sol-gel thin films. © 2012 Elsevier Ltd. All rights reserved.


Bura T.,Laboratoire Of Chimie Organique Et Spectroscopies Avancees Lcosa | Ziessel R.,Laboratoire Of Chimie Organique Et Spectroscopies Avancees Lcosa
Tetrahedron Letters | Year: 2010

Several new fluorophores have been prepared by grafting boradiazaindacene (red absorbing) and/or styrylboradiazaindacene (blue absorbing) units as terminal energy acceptors onto a fluorene-derived platform. In one case, an amino-bis(bipyridine) pocket has been attached to enable strong binding of transition metal ions. The stepwise syntheses were largely based on Pd-catalysed cross-coupling reactions. The electrochemistry of the dyes has been analysed by reference to the properties of the various synthetic intermediates, protonation of the tertiary amine site present in the bis(bipyridine) species enabling processes involving this centre to be distinguished from those associated with the boradiazaindacene (Bodipy) unit. © 2010 Elsevier Ltd. All rights reserved.


Bura T.,Laboratoire Of Chimie Organique Et Spectroscopies Avancees Lcosa | Nastasi F.,Messina University | Puntoriero F.,Messina University | Campagna S.,Messina University | Ziessel R.,Laboratoire Of Chimie Organique Et Spectroscopies Avancees Lcosa
Chemistry - A European Journal | Year: 2013

A series of new compounds in which various Bodipy dyes are grafted logically on triptycene rigid structures are synthesized and characterized, and their absorption spectra and photophysical properties are studied, also by pump-probe transient absorption spectroscopy. The studied compounds are: the mono-Bodipy species TA, TB, and TC (where A, B, and C identify different Bodipy subunits absorbing and emitting at different wavelengths), the multichromophore species TA3, which bears three identical A subunits, and the three multichromophoric species TAB, TBC, and TABC, all of them containing at least two different types of Bodipy subunits. The triptycene moiety plays the role of a rigid scaffold, keeping the various dyes at predetermined distances and allowing for a three-dimensional structural arrangement of the multichromophoric species. The absorption spectra of the multichromophoric Bodipy species are essentially additive, indicating that negligible inter-chromophoric interaction takes place at the ground state. Luminescence properties and transient absorption spectroscopy indicate that a very fast (on the picosecond time scale) and efficient photoinduced energy transfer occurs in all the multi-Bodipy species, with the lower-energy Bodipy subunits of each multi-Bodipy compounds playing the role of an electronic energy collector. In TAB, an energy transfer from the A-type Bodipy subunit to the B-type one takes place with a rate constant of 1.6×1010 s-1, whereas in TBC an energy transfer from the B-type Bodipy subunit to the C-type subunit is bi-exponential, exhibiting rate constants of 1.7×1011 and 1.9×10 10 s-1; the possible presence of different conformers with different donor-acceptor distances in this bichromophoric species is proposed to cause the bi-exponential energy-transfer process. Interpretation of the intricate energy-transfer pathways occurring in TABC is made with the help of the processes identified in the bichromophoric compounds. In all cases, the measured energy-transfer rate constants agree with a Förster mechanism for the energy-transfer processes. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Bura T.,Laboratoire Of Chimie Organique Et Spectroscopies Avancees Lcosa | Hablot D.,Laboratoire Of Chimie Organique Et Spectroscopies Avancees Lcosa | Ziessel R.,Laboratoire Of Chimie Organique Et Spectroscopies Avancees Lcosa
Tetrahedron Letters | Year: 2011

Several new extended fluorescent dyes have been prepared by stepwise functionalisation of the methyl groups located in the 1, 3, 5, and 7 substitution positions of Bodipy dyes. In one case, a ferrocene residue has been connected, giving rise to severe fluorescence quenching and a rich redox behavior. The stepwise syntheses were largely based on Knoevenagel reactions allowing the attachment of three different modules in a tetravinyl configuration. Most of these dyes exhibit reversible formation of radical cations and radical anions, as well as an irreversible formation of dications and dianions. Spectroscopic examination of the dyes under various conditions including the presence of acid leads to the conclusion that the delocalization is more effective in the 3,5-substitution positions than in the 1,7-positions. These novel dyes have absorption and emission wavelengths spanning the ranges of 573-718 nm and 585-778 nm, respectively. © 2011 Elsevier Ltd. All rights reserved.


Niu S.,Laboratoire Of Chimie Organique Et Spectroscopies Avancees Lcosa | Ulrich G.,Laboratoire Of Chimie Organique Et Spectroscopies Avancees Lcosa | Retailleau P.,French National Center for Scientific Research | Ziessel R.,Laboratoire Of Chimie Organique Et Spectroscopies Avancees Lcosa
Tetrahedron Letters | Year: 2011

A series of BODIPY bridged push-pull chromophores were prepared by a sequence of reactions involving: i) cross-coupling reactions promoted by palladium complexes; ii) Knoevenagel condensation leading to dicyano derivatives; iii) [2+2] cycloaddition. The last reaction is regioselective, providing mono-derivatives with anisole substituents. With dimethylaminophenyl donor groups, double addition is feasible, providing highly colored dyes displaying remarkable electrochemical properties. © 2011 Elsevier Ltd. All rights reserved.

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