Vibrational Frequencies and Ionization Energy of Bis(η6-Benzene)Chromium as Studied by Density Functional Theory

Abstract

The geometry of the bis(η6-benzene)chromium neutral molecule 1 and cation 1 + have been optimized at various DFT levels with use of LSDA, GGA and hybride functionals. An increase in the Cr–C distances and a decrease in the C–H distances on ionization is observed. The vibrational frequencies of 1, 1 + and their deuterated derivatives as well as the ionization potentials of the neutral molecules have been calculated and compared with the experimental data obtained for the gas-phase species. An excellent agreement with the experiment was achieved at the BPW91/TZVP level of theory for all the molecular parameters investigated including a negative shift of the ionization energy on deuteration.