Insights into the structure of cyclohexane from femtosecond degenerate four-wave mixing spectroscopy and ab initio calculations

Christoph Riehn; Victor V Matylitsky; Włodzimierz Jarzeba; Bernd Brutschy; P Tarakeshwar; Kwang S Kim

doi:10.1021/ja036615o

Insights into the structure of cyclohexane from femtosecond degenerate four-wave mixing spectroscopy and ab initio calculations

J Am Chem Soc. 2003 Dec 31;125(52):16455-62. doi: 10.1021/ja036615o.

Authors

Christoph Riehn¹, Victor V Matylitsky, Włodzimierz Jarzeba, Bernd Brutschy, P Tarakeshwar, Kwang S Kim

Affiliation

¹ Wolfgang Goethe-Universität Frankfurt/M., Institut für Physikalische und Theoretische Chemie, Marie-Curie-Str. 11, D-60439 Frankfurt/M., Germany. riehn@chemie.uni-frankfurt.de

PMID: 14692789
DOI: 10.1021/ja036615o

Abstract

In this paper, we report the use of femtosecond time-resolved degenerate four-wave mixing rotationally resolved spectroscopy to obtain very accurate structural information on the symmetric top cyclohexane. Apart from highlighting the versatility of this method in determining accurate structures of large and complex molecules without dipole moment, the present study also details the comparison of the experimentally determined rotational constant B(0) with that obtained from high-level ab initio calculations. The theoretical calculations, which were carried out at both the second-order Møller-Plesset (MP2) and coupled-cluster with single, double, and perturbative triple substitutions [CCSD(T)] levels of theory, also take into account vibrational averaging effects. A detailed investigation of the vibrational averaging effects reveals that the corrections emerge from only the six highly symmetric A(1g) modes, a justification of which is provided by an analysis of these modes.