Sterically congested molecules. Part 2. Structure of N-(2,2,5,5-tetramethylcyclopentylidene)-4-amino-3,5-dimethylphenol: accommodation of front strain along the CN double bond

Abstract

A crystal of the title compound was found to be composed of two kinds of independent molecules, 1 and 1′, which are interconnected by a rare type OH ⋯ OH ⋯ N of hydrogen bonding. Despite their different role in such hydrogen bonding, both molecules have similar structural properties. Front strain along the CN double bonds, as characterized by intramolecular non-bonding distances, appears to be accommodated by moderate widening of mainly the CN–C angles together with a somewhat smaller opening of the C–CN angles but little deformation of the aromatic ring.