A bis-chelate o -vanillin-2-ethanolamine copper(II) complex bearing both imine and amine forms of the ligand

The molecular bis-chelate complex (2-{[(2-hydroxyethyl-κ O )amino-κ N ]methyl}-6-methoxyphenolato-κ O )(2-{[(2-hydroxyethyl)imino-κ N ]methyl}-6-methoxyphenolato-κ O )copper(II), [Cu(C 10 H 14 NO 3 )(C 10 H 12 NO 3 )] or [Cu(H L im )(H L am ); H L im = C 10 H 14 NO 3 ; H L am = C 10 H 12 NO 3 , represents the first compound containing a salicylidene-2-ethanolamine type ligand in both imino H L im (Schiff base) and amino H L am (reduced Schiff base) forms that has been structurally characterized on the basis of X-ray data. Two molecules of the monodeprotonated ligands coordinate the Cu II ion in an ( N , O phen )-bidentate and an ( N , O phen , O alc )-tridentate fashion in the case of the imino and amino forms, respectively. The shape of the CuN 2 O 3 coordination polyhedron is a distorted square-pyramid (geometry index τ 5 = 0.26). Intermolecular N—H...O and O—H...O hydrogen bonds, involving H atoms of the amino and hydroxyethyl groups, create a two-dimensional supramolecular array extending parallel to (010).