Description of cross peaks induced by intermolecular vibrational energy transfer in two-dimensional infrared spectroscopy

摘要

In the present work, the analytical description of an intermolecularvibrational energy transfer, analyzed by two dimensional infrared spectroscopy,is established. The energy transfer process takes place between the darkcombination states of low frequency modes pertaining to different molecules.The appearance of the cross peaks results from coherent transfer between thesecombination states and an optically active state of the acceptor molecule. Sucha process has recently been observed experimentally between the nitrile groupsof acetonitrile-d3 and benzonitrile molecules. This molecular system will beused as a model for the simulations of their two-dimensional infrared spectra.The dependence of the cross-peak growth, which is a signature of theintermolecular energy transfer, will be discussed in detail as a function ofthe molecular dynamical constants.