Copper(II), zinc(II) and nickel(II) coordination polymers using bidentate hyroxyphenyl-tetrazolyl ligand

Herein, we report various metal complexes containing {5-(2-hydroxy)phenyl}tetrazolyl (H2hptz) which form various high-dimensional coordination polymers in a crystalline solid state. A reaction of metal perchlorates, 2,2′-bipyrimidine (bpym), KOH, and tetrazolyl ligand (H2hptz) in H2O or N,N-dimethylmethanamide (DMF) yield 2-D [Cu(hptz)(bpym)]n (1), [Zn(hptz)(bpym)]n (2) and 3-D [K(bpym)2Ni(hptz)(H2O)2.5(OH)]n (3) coordination complexes with a high synthetic yield. These compounds were characterized by elemental analysis, IR spectroscopy, and single crystal X-ray crystallography. Cu2+ and Zn2+ complexes showed 2-D infinite network systems, forming coordination polymers (caused by extra bonding between metal ions and tetrazolyl). The environment of the Cu and Zn metal centers are quite similar; however, Zn2+ complexes have significantly shorter Zn–O bond distances with the hydroxyl group of other [Zn(hptz)(bpym)] unit. The Ni2+ complex 3 showed a completely different composition from that of complexes 1–2. Complex 3 showed 3-D structure based on octahedral units, which were composed of two hptz2− and one bpym ligands around the Ni center. These units infinitely repeat with K ions and water molecules along the a-, b-, and c-axes of the unit cells. Their magnetic behaviors were also studied.

Three interesting coordination polymers containing the {5-(2-hydroxy)phenyl}tetrazolyl ligand (H2hptz) were synthesized from a simple one step reaction. The solid state structures were confirmed by X-ray crystallography. Depending on the used metal precursors, different dimensionalities were observed.Figure optionsDownload as PowerPoint slide