Syntheses and structural characterization of three coordination polymers of Cd(II), Zn(II) and Pb(II) with the “V” shape ligand 4,4′-[isopropylidenebis(p-phenyleneoxy)]diacetic acid

Three new inorganic–organic coordination polymers based on a “V” shape linking unit 4,4′-[isopropylidenebis(p-phenyleneoxy)]diacetic acid (H2L) and CdII, ZnII and PbII ions, [Cd(L)(H2O)2]n (1), [Zn2(L)3(H2O)6·6H2O]n (2) and [Pb2Na2(L)3(DMF)4(H2O)2·2H2O]n (3), have been prepared and structurally characterized by single-crystal X-ray diffraction analysis. Complex 1 is a 1D zig-zag chain coordination polymer, which is connected by strong hydrogen-bond interactions to result in a 3D network. In complex 2, an infinite 2D (6, 3) network with large hexagonal cavities was created. The whole 2D structure is a noninterpenetrating framework stacked by hydrogen-bonding interactions. Complex 3 is a novel 3D heterometallic coordination polymer, which possesses three different types of isolated channels.