6,6′-Dimethoxy-2,2′-[2,2-dimethylpropane-1,3- diylbis(nitrilomethylidyne)]diphenol

Abstract

The title Schiff base compound, C21H26N2O4, exhibits two crystallographically independent mol-ecules in the asymmetric unit with similar conformations. The imino groups are coplanar with the benzene rings; the maximum deviations of the N atoms from the planes comprising the benzene rings and the imino groups are -0.037 (4), 0.013 (4), -0.021 (5), and 0.008 (5) Å. The dihedral angles between the benzene rings in the two mol-ecules are 53.64 (17) and 51.93 (17)°. Strong intra-molecular O - H⋯N hydrogen bonds generate S(6) ring motifs. The N atoms are also in close proximity to the H atoms of the dimethyl-propane groups, with H⋯N distances between 2.54 and 2.75 Å. The crystal structure is further stabilized by weak inter-molecular C - H⋯O hydrogen bonds, weak inter-molecular C - H⋯π inter-actions and π-π contacts involving the imine C atom and two C atoms from the adjacent benzene rings.