Liquid crystal nuclear magnetic resonance investigation on the structure of a molecule formed by two fused six-membered rings: 2, 7-naphthyridine

The n.m.r. spectrum of the 2,7-naphthyridine partially oriented in the nematic phase of a liquid crystalline solvent has been obtained and interpreted in terms of chemical shifts, spin–spin coupling constants, and direct dipolar couplings. The ratio of the interprotonic distances has been deduced and the molecular shape obtained. Comparison of the experimental molecular shape with that of pyridine shows that negligible molecular deformations occur when fusing two six-membered rings.