KiNEEt: Aplicación para el aprendizaje y rehabilitación en educación especial

International audienc

DFT study of chemiluminescence and fluorescence of coumaranone derivatives

International audienc

Multiscale modelling of the light emitter system in firefly bioluminescence

International audienc

QM/MM Study of Bioluminescent Systems

International audienc

Systèmes bioluminescents: ce qu’apportent les études théoriques

National audienc

Mechanistic insights into chemiluminescent decomposition of firefly dioxetanone

The decomposition mechanism and pathway of the firefly dioxetanone have never been explored at a reliable theoretical level before. The difficulty is that the decomposition process includes biradical, charge-transfer (CT) and several nearly degen- erated states, which is in need of multireference method for considering several states simultaneously with an active space available to the whole reaction process. We have investigated the thermolysis of firefly dioxetanone in both neutral (FDOH) and anionic (FDOÀ) forms in gas phase and solvents by the mul- tistate second-order multiconfigurational perturbation (CASPT2) theories in coordination with the ground-state intrinsic reac- exchange-correlation (CAM-B3LYP). The size of selected active spaces have been validated adequate large for handing the whole reaction processes of the decompositions of FDOH and FDOÀ, together with the assistance of state-average (SA) tech- nique. The decomposition processes of FDOH and FDO- were explored in details. The activation energy of FDOÀ is 5.9 kcal/mol smaller than that of FDOH by the CASPT2 cal- culations, which once again indicates the necessary of depro- present calculations, the chemically initiated electron exchange luminescence (CIEEL) and charge-transfer initiated luminescence (CTIL) mechanisms were extremely discussed

Blue-Green-Red bioluminescence: theoretical insights

invited seminar by Hidefumi Akiyama, University of Tokyo, The Institute for solid state physic

QM/MM study of firefly bioluminescence

International audienceThe emitting light in fireflies arises from the electronic relaxation of oxyluciferin, an organic compound resulting from the oxidation of the D-luciferin substrate inside an enzyme called luciferase. In order to theoretically study such systems, the use of quantum mechanical/molecular mechanical (QM/MM) methods is required. Accurate QM level is needed for dealing with electronic transition and charge transfer phenomena. Taking into account the surrounding protein at the MM level is essential in order to understand the colour modulation and influence of the enzyme.The present lecture will discuss some of the results obtained on this system with calculations done with the coupling of the programs MOLCAS (CASPT2/CASSCF) or G09 (DFT) and TINKER (AMBER force field) and how the complementary of experimental data and theoretical results can give understanding of such phenomenon.The transition energy corresponding to a fluorescence experiment for the wild type emitter and a modified emitter will be presented.Calculations give insights to decipher the emitter conformation even with a lack of experimental crystallographic structure. And insights to explain the color modulation due to the surrounding environment

Spectroscopie de chromophores issus de la bioluminescence dans un solvant ou une protéine

International audienc