On the Biradicaloid Nature of Long Quinoidal Oligothiophenes: Experimental Evidence Guided by Theoretical Studies

Abstract

Raman spectroscopy in conjunction with quantum chemistry allows efficient inspection of the electronic and structural properties of biradicals. Investigations on a series of quinoidal oligothiophenes uncover a thermal equilibrium between singlet and triplet biradical states (see picture) for the longest of the investigated systems.