A diversity of hydrogen bond motifs in the crystal structures of nickel(II) and copper(II) complexes with N-arylalkyliminodiacetamides

Abstract

The reactions of N-arylalkyl derivatives of iminodiacetamide (Bnimda, Peimda, Ppimda; Bn=benzyl, Pe=2-phenylethyl; Pp=3-phenylprop-1-yl) with nickel(II) and copper(II) salts in aqueous solutions were investigated. Four new nickel(II) complexes and three new copper(II) complexes [Ni(Bnimda)2](NO3)2·2H2O (1), [Ni(Peimda)2](NO3)2 (2), [Ni(Peimda)2]SO4·2H2O (3), [Ni(Ppimda)2](NO3)2·4H2O (4), [Cu(Bnimda)2](NO3)2·H2O (5), [Cu(Peimda)2](NO3)2·4H2O (6) and [Cu(Ppimda)2](NO3)2 (7) were prepared and characterized by infrared spectroscopy and thermal analysis (TG/DTA). The distorted octahedral coordination environments around the nickel(II) and copper(II) ions in complexes 1, 2, 3, 5 and 6 consist of two O,N,O′-tridentate N-arylalkyliminodiacetamide ligands, with imino N atoms in trans-position. Various hydrogen bond motifs were found in the crystal structures of these complexes – trimeric, tetrameric, pentameric and hexameric ring motifs. These motifs were formed by the amide moieties and by the oxoanions (nitrate or sulfate) and water molecules.