Disentanglement of triplet and singlet states of azobenzene: direct EELS detection and QMC modeling

Dubecký, M.; Derian, R.; Horváthová, L.; Allan, Michael; Štich, I.

doi:10.1039/C1CP22520K

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Journal article

Disentanglement of triplet and singlet states of azobenzene: direct EELS detection and QMC modeling

Dubecký, M. Institute of Physics, Center for Computational Materials Science, Slovak Academy of Sciences, Bratislava, Slovakia
Derian, R. Institute of Physics, Center for Computational Materials Science, Slovak Academy of Sciences, Bratislava, Slovakia
Horváthová, L. Institute of Physics, Center for Computational Materials Science, Slovak Academy of Sciences, Bratislava, Slovakia
Allan, Michael Department of Chemistry, University of Fribourg, Switzerland
Štich, I. Institute of Physics, Center for Computational Materials Science, Slovak Academy of Sciences, Bratislava, Slovakia

17.10.2011

Published in:

Physical Chemistry Chemical Physics. - 2011, vol. 13, p. 20939-20945

English Singlet and triplet excited states of trans-azobenzene have been measured in the gas phase by electron energy loss spectroscopy (EELS). In order to interpret the strongly overlapping singlet and triplet bands in the spectra a set of large-scale correlated quantum Monte-Carlo (QMC) simulations was performed. The EELS/QMC combination of methods yields an excellent agreement between theory and experiment and for the two low-lying excited singlet and two low-lying triplet states permitted their unambiguous assignment. In addition, EELS revealed two overlapping electronic states in the band commonly assigned as S2, the lower one with a pronounced vibrational structure, the upper one structureless. Finally, the agreement between theory and experiment was shown to further increase by taking computationally into account the finite temperature effects.

Faculty

Faculté des sciences et de médecine

Department

Département de Chimie

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