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

The title Schiff base compound, C21H26N2O4, exhibits two crystallographically independent molecules 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) angstrom. The dihedral angles between the benzene rings in the two molecules are 53.64 (17) and 51.93 (17)degrees. Strong intramolecular O-H N hydrogen bonds generate S( 6) ring motifs. The N atoms are also in close proximity to the H atoms of the dimethylpropane groups, with H center dot center dot center dot N distances between 2.54 and 2.75 angstrom. The crystal structure is further stabilized by weak intermolecular C-H center dot center dot center dot O hydrogen bonds, weak intermolecular C- H center dot center dot center dot pi interactions and pi-pi contacts involving the imine C atom and two C atoms from the adjacent benzene rings.