Two (E)-2-({[4-(dialkyl-amino)-phenyl]imino}-meth-yl)-4-nitro-phenols

Abstract

The slow evaporation of analytical NMR samples resulted in the formation of crystals of (E)-2-({[4-(dimethyl-amino)-phenyl]-imino}-methyl)-4-nitro-phenol, C15H15N3O3, (I), and (E)-2-({[4-(diethyl-amino)-phenyl]-imino}-methyl)-4-nitrophenol, C 17H19N3O3, (II). Despite the small structural difference between these two N-salicylidene-aniline derivatives, they show different space groups and diverse mol-ecular packing. The mol-ecules of both compounds are close to being planar due to an intra-molecular O - H⋯N hydrogen bond. The 4-alkyl-amino-substituted benzene ring is inclined at an angle of 13.44 (19)° in (I) and 2.57 (8)° in (II) with respect to the 4-nitro-substituted phenol ring. Only very weak inter-molecular π-π stacking and C - H⋯O inter-actions were found in these structures. © 2012 International Union of Crystallography.