title: Vibrational relaxation of C-D stretching vibrations in CDCl3, CDBr3, and CDI3.
abstract: We present time-resolved transient grating measurements of the vibrational relaxation rates of the C-D stretching vibrations of deuterated haloforms in benzene and acetone. We compare our results with previous measurements of excited C-H stretches in the same solvents to obtain insight into the solvent effect on the vibrational relaxation. In deuterated molecules, there are more low-order-coupled states and the states are closer in energy to the C-D stretch than in the unlabeled isotopologs. Therefore, the relaxation is faster for the deuterated molecules. The relaxation also shows a significant solvent dependence. Bromoform and iodoform form charge-transfer complexes with both benzene and acetone which enhance the relaxation rate. For chloroform, hydrogen bonding to acetone is expected to be a more favorable interaction. Surprisingly, however, the vibrational relaxation of CDCl(3) is slower in acetone than in benzene.
authors.affiliation: Chemistry Department, The University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Kenan
authors.initials: K
authors.lastname: Gündoğdu
authors.forename: Michael W
authors.initials: MW
authors.lastname: Nydegger
authors.forename: Jigar N
authors.initials: JN
authors.lastname: Bandaria
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Hill
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Cheatum