Structural correlations among aromatic azine derivatives

This paper is a sequel to the ARKIVOC publication [2002 (iii) 103-111] describing the spontaneous conversion of the methochloride (A) of salicylaldazine to the azine (B), which is considered to take place via the oxidation of an N-alkylhydrazone.X-Ray crystallographic aspects of (A), (B) and three related compounds are presented, and a survey given of the conformations of a number of derivatives of the parent compound benzaldazine.Three categories of structure are discerned, one essentially planar, another twisted as a consequence of steric interactions in the neighborhood of the azine system, and a third group having further distinctive features including extreme deviations from planarity.