Synthesis and crystal structures of metal complexes with 4,5-imidazole-dicarboxylate chelates: self-assembled structures via NH⋯Odouble bond; length as m-dashC intermolecular hydrogen bonds

New metal complexes with two imidazole-carboxylate sets, [Zn(hmia)2(H2O)2] (hmia = 1-hydroxymethyl-4-imidazoleacetate) (1) and [M(Himdc)2(H2O)2] (imdc = 4,5-imidazoledicarboxylate) (M = Zn (2), Co (3), Cu (4)), were synthesized and structurally characterized. For all metal complexes, coordination of the two N–O sets of chelating ligands and two water molecules produces a distorted (1–3) and an elongated (4) octahedral coordination center, in which these monomeric units are connected by various intermolecular hydrogen bonds.