Nematic-phase nuclear magnetic resonance investigation of rotational isomerism. Part 7. An investigation into the structure of 2,2′-bipyridyl using the proton and deuterium spectra of liquid crystalline solutions

Abstract

A 220 MHz proton n.m.r. spectrum of 2,2′-bipyridyl in a nematic phase solution has been analysed to yield a set of dipolar coupling constants, D_ij. The couplings D_ij are not in complete agreement with a description of the molecule as a single conformation. The trans-form alone occurs in solid, 2,2′-bipyridyl, but although this is probably the predominant form in the liquid state, there does appear to be a difference between the molecular structure in the two phases.