Vibrational Raman Shifts and Aromaticity: The Case of Oligothiophenes

Abstract

A general description of the use of the Raman spectra of polyconjugated molecules to infer their electronic and molecular properties and how these change in a number of situations is illustrated with several examples, with particular emphasis on oligothiophene molecules. The most noticeable features of the Raman spectra of these molecules and the main theoretical models developed for their understanding have been revised and explained in terms related to π-electron delocalization intimately connected with the aromatic and quinoidal characters.

Keywords: Raman spectroscopy; conjugation; oligomers; oligothiophenes; organic molecular materials.