Hydrogen bonding in simple π-electron systems II. Pyridine–pyrrol

Previous work in this laboratory concerning the properties of hydrogen bonds in the base pairs of DNA [1–6] has led to considerable interest in the properties of hydrogen bonds in π-electron systems. The first paper in this series [7] has investigated the usefulness of the LCAO –MO –SCF method and the Pariser–Parr–Pople approximation as applied to this problem, by calculation on the ideal pyridine–pyridinium complex. In this paper, a relation with experiment will be established by comparison of the results obtained from this method of calculation with the properties of the experimentally observable pyridine–pyrrol system.