title: Photoexcitation and relaxation kinetics of molecular systems in solution: towards a complete in silico model.
abstract: In this study, we have modelled, through a theoretical-computational approach based on classical molecular dynamics simulations and quantum-chemical calculations, the complete relaxation process of a photo-excited ionic stilbene-like compound termed as DASPMI in solution. Starting from the absorption spectrum we have reconstructed the entire process of the excited-state relaxation involving the intramolecular charge-transfer and eventually leading to the charge-recombination regenerating the ground state. The results obtained, well reproducing the experimental time-resolved emission spectra and kinetic observables, show that the relaxation process is essentially driven by the internal conformational transitions of the chromophore with the solvent almost instantaneously relaxed for each chromophore conformation. This study represents the first attempt, carried out using our theoretical-computational approach, of modelling a complete experiment involving the overposition of relaxation kinetics ranging from hundreds of femtoseconds to nanoseconds on the time scale.
authors.affiliation: Dipartimento di Scienze Fisiche e Chimiche, University of l'Aquila, Italy. massimiliano.aschi@univaq.it.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Aschi
authors.affiliation: Scuola Normale Superiore, Pisa, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Barone
authors.affiliation: Department of Chemistry, Biology and Biotechnology and Centro di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN), University of Perugia, via Elce di Sotto 8, 06123 Perugia, Italy.
authors.forename: Benedetta
authors.initials: B
authors.lastname: Carlotti
authors.affiliation: Dipartimento di Scienze Fisiche e Chimiche, University of l'Aquila, Italy. massimiliano.aschi@univaq.it.
authors.forename: Isabella
authors.initials: I
authors.lastname: Daidone
authors.affiliation: Department of Chemistry, Biology and Biotechnology and Centro di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN), University of Perugia, via Elce di Sotto 8, 06123 Perugia, Italy.
authors.forename: Fausto
authors.initials: F
authors.lastname: Elisei
authors.affiliation: Dipartimento di Scienze e Tecnologie Chimiche, Universiy of Roma Tor Vergata, Via della Ricerca Scientifica, 00100 Roma, Italy. andrea.amadei@uniroma2.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Amadei