On the magnetic circular dichroism of benzene. A density-functional study

0475312 - ÚOCHB 2018 RIV US eng J - Článek v odborném periodiku
Kaminský, Jakub - Kříž, Jan - Bouř, Petr
On the magnetic circular dichroism of benzene. A density-functional study.
Journal of Chemical Physics. Roč. 146, č. 14 (2017), č. článku 144301. ISSN 0021-9606. E-ISSN 1089-7690
Grant CEP: GA ČR GA13-03978S; GA ČR(CZ) GA16-05935S
Institucionální podpora: RVO:61388963
Klíčová slova: magnetic circular dichroism * benzene * DFT
Obor OECD: Physical chemistry
Impakt faktor: 2.843, rok: 2017

Spectroscopy of magnetic circular dichroism (MCD) provides enhanced information on molecular structure and a more reliable assignment of spectral bands than absorption alone. Theoretical modeling can significantly enhance the information obtained from experimental spectra. In the present study, the time dependent density functional theory is employed to model the lowest-energy benzene transitions, in particular to investigate the role of the Rydberg states and vibrational interference in spectral intensities. The effect of solvent is explored on model benzene-methane clusters. For the lowest-energy excitation, the vibrational sub-structure of absorption and MCD spectra is modeled within the harmonic approximation, providing a very good agreement with the experiment. The simulations demonstrate that the Rydberg states have a much stronger effect on the MCD intensities than on the absorption, and a very diffuse basis set must be used to obtain reliable results. The modeling also indicates that the Rydberg-like states and associated transitions may persist in solutions. Continuum-like solvent models are thus not suitable for their modeling, solvent-solute clusters appear to be more appropriate, providing they are large enough.
Trvalý link: http://hdl.handle.net/11104/0272147