Effect of Local Structure on Rotational Contributions in the Ultrafast Optical Kerr Effect in Pure Liquid Acetonitrile and Dimethyl Sulfoxide

Abstract

The relationship between the structures of liquid acetonitrile (AN) and dimethyl sulfoxide (DMSO) and rotational contributions in the ultrafast optical Kerr effect is considered. It is shown that the structure of associates in the form of chains impedes the emergence of induced orientational anisotropy of molecules in liquid DMSO. In liquid AN, antiparallel dimers are capable of reorientation under the action of a pump laser field; both dimers and monomers contribute to the libration response.