Addition reactions of heterocyclic compounds. Part XLIII. Rotational isomerism of 5-oxidovinylphenanthridiniums: an investigation by variable temperature nuclear magnetic resonance spectroscopy
Abstract
5-Oxidovinylphenanthridiniums with 6-aryl substituents exhibit cis–trans and rotational isomerism. The nature of the species involved has been elucidated by variable temperature n.m.r. spectroscopy and by observation of the properties of related compounds.