The excited state behaviour of medium/large size molecules in the condensed phase: insights from static and dynamical quantum mechanical approaches

Roberto Improta
Istituto IBB-CNR Via Mezzocannone 16, 80134 Napoli, Italy
E-mail: robimp@unina.it

Lundi, 7 novembre 2011,
11h00 Bibliothèque 4e étage,
tour 12 - 13, site Jussieu


The approach we have developed in the last years to study the excited state properties of molecules in solution is described.[1] Methods rooted in the Time-Dependent Density Functional theory (TD-DFT), when using suitable functionals, can provide an accurate description of the energy, structure and properties of the excited states. Bulk solvent effects are included by means of the Polarizable Continuum Model (PCM), resorting to mixed explicit/implicit solvation models to treat hydrogen-bonding solvents. In this framework, State-Specific implementation of PCM/TD-DFT can provide a very accurate description of static and dynamic solvation effect on optical spectra.[2-3] Finally, effective methods have been developed to compute vibrationally resolved absorption and emission spectra.[4,5] This approach is able to provide optical spectra that, without resorting to any empirical parameter, can be directly compared with experiments. [1-6] For what concerns the excited state dynamics, we have used two complementary approaches. We have tried to describe, at a fully Quantum Mechanical level, systems as close as possible to those studied by experimentalists and we have developed suitable Quantum Dynamical approaches, providing results directly comparable to Time Resolved experiments.[7-13] The results obtained in the study of the excited state dynamics in nucleobases and in oligonucleotides in solution are briefly described.
[1] V. Barone, R. Improta, N. Rega Acc. Chem. Res. 41, 605 (2008)
[2] R. Improta,V. Barone, G. Scalmani, V. Barone J. Chem. Phys. 125, 54103 (2006)
[3] R. Improta G. Scalmani, M.J. Frisch Michael, V. Barone J. Chem. Phys. 127, 74504 (2007)
[4] R. Improta, V. Barone, F. Santoro Angew. Chemie 46, 405 (2007)
[5] F. Santoro, R. Improta, A. Lami, J. Bloino, V. Barone, J. Chem. Phys. 126, 84509 (2007)
[6] F. Avila Ferrer, R. Improta F. Santoro, V. Barone, Phys. Chem. Chem. Phys. 13, 17007 (2011)
[7] T. Gustavsson R. Improta , D. Markovitsi J. Phys. Chem. Lett. 1, 2025 (2011)
[8] F. Santoro, V. Barone, R. Improta Proc. Natl. Acad. Sci. U. S. A. 104, 9931 (2007)
[9] R. Improta, V. Barone, Angew. Chemie (2011) in press
[10] F.Santoro, V.Barone, R. Improta J. Am. Chem. Soc. 131, 15232 (2009)
[11] V. Karunakaran, Kleinermanns, R. Improta, S.A. Kovalenko, J. Am. Chem. Soc. 131, 5839 (2009)
[12] R. Improta, F. Santoro, V. Barone, A. Lami J. Phys. Chem. A, 113, 15346 (2009)
[13] D. Picconi, V. Barone, A. Lami, F. Santoro, R. Improta ChemPhysChem 12, 1957 (2011).