The electronic structure of heteroaromatic molecules. Part 2. Five-membered rings
Abstract
Spin-coupled theory is applied to the π electrons of the heteroaromatic molecules furan, pyrrole, thiophene, and thiazole. As is the case for the six-membered rings considered in the companion paper, the electronic structure is described well in terms of localized but non-orthogonal orbitals. The characteristic stability of aromatic molecules results from the mode of spin coupling rather than from delocalized orbitals. The photoelectron spectra of these molecules are also considered briefly.