On the value of the depolarization ratio of fundamentals of sandwich compounds with an electronically degenerate ground state

Abstract

The selection rules are derived for the Raman activity of fundamental modes in electronically degenerate groundstates of sandwich compounds. Emphasis is placed on the occurrence of asymmetric tensors, which can result in values of the depolarization ratio of Raman bands larger than t. Journal of Raman Spectroscopy 4 (1976) 305-311. All Rights Reserved Copyright 0 1976 by D. Reidel Publishing Company, Dordrecht-Holland

Origin of asymmetric scattering tensors of normal modes in electronically degenerate states

“…IoC lalctAB + as%l(A ) + a3~ol(B)I s (3) where al, a s and a a are mixing coefficients. ~AB stands for the electronic Raman integral S ~bA*~ dr and %1(A) and ~01(B) are vibrational Raman processes for transitions v= 1 ~v=0 in the electronic states eA and eB.…”

“…Recently one of us proposed a theory to find the form of the Raman tensor for normal modes in an electronically degenerate state of molecules having Dab symmetry [2]. This theory was also applied to the chromocene molecule [3] and in both cases an analysis was made of the form of the scattering tensor of normal modes in the Raman spectra. In the present paper we extend our previous findings to all modes in degenerate electronic states of molecules belonging to point groups having three, four, five and six-fold rotational axis.…”