Raman excitation profiles and excited state molecular configurations of three isomeric phenyl pyridines

Contributions of different electronic states to Raman scattering have been studied by critical analyses of Raman excitation profiles (REPs) of several normal modes of vibration of three isomeric phenyl pyridines. In this cont ext, possible structures and other interesting properties of the three mole cules in the excited electronic states have been discussed. Normal mode cha racteristics are also described. Most likely a singlet state, lying in the vacuum ultraviolet region with respect to the ground state, is found to be playing a very significant role in the scattering phenomena. (C) 2000 Elsev ier Science B.V. All rights reserved.