A novel O-Zn bridging polymer complex of 2,6-bis[bis(carboxylatomethyl) aminomethyl]-4-methylphenolate

A new one-dimensional coordination polymer, catena-poly[[acetatohexa­aqua­{μ4-2,6-bis­[bis­(carboxyl­ato­meth­yl)am­ino­meth­yl]-4-methyl­phenolato}­trizinc(II)] octa­hydrate], [Zn3(C17H17N2O9)(C2H3O2)(H2O)6]·8H2O, is a trinuclear complex consisting of three zinc centers joined by a phenolate bridge and Zn(H2O)4 units. In each complex polymer unit, the three Zn atoms have different coordination modes. Of the two phenolate-bridged Zn ions, one adopts a distorted octa­hedral coordination composed of two carboxyl­ate ligands, one tertiary N atom, two water mol­ecules and the bridging phenolate ligand, while the other adopts a pyramidal geometry composed of two carboxyl­ate ligands, one tertiary N atom from another coordination arm, one acetate anion as the counter-anion and the bridging phenolate ligand. The third type of Zn centre is represented by two independent Zn atoms lying on inversion centres. They both have an octa­hedral coordination consisting of four O atoms from four water mol­ecules and two acetate carbonyl O atoms from the ligand. The latter Zn atoms join the above-mentioned binuclear complex units through O atoms of the carboxyl­ate groups into an infinite chain. Neighboring aromatic rings are distributed above and below the chain in an alternating manner. Between the coordination chains, the Zn⋯Zn separations are 5.750 (4) and 6.806 (4) A. The whole structure is stabilized by hydrogen bonds formed mainly by solvent water mol­ecules.