Synthesis, structure and property of Ni(II) coordination polymers with mixed dicarboxylate and benzoimidazol-containing ligands

Abstract Four new Ni(II) complexes [Ni(L)(SO 4 )(H 2 O) 2 ]·H 2 O ( 1 ), [Ni 3 (L) 4 ( p -BDC) 3 (H 2 O) 6 ]·6H 2 O ( 2 ), [Ni(L)( m -BDC)(H 2 O) 2 ]·0.5H 2 O ( 3 ) and [Ni(L)(BPDC)(H 2 O) 2 ] ( 4 ) have been prepared by reactions of 3,5-di(1 H -benzimidazol-1-yl)pyridine (L) with nickel sulfate in the presence of auxiliary ligands of phthalic acid ( o -H 2 BDC), terephthalic acid ( p -H 2 BDC), isophthalic acid ( m -H 2 BDC) and biphenyl-4,4′-dicarboxylic acid (H 2 BPDC), respectively. Interestingly, phthalate ( o -BDC 2− ) did not take part in formation of 1 , instead SO 4 2 - was found in 1 . Complex 2 with p -BDC 2− shows different two-dimensional (2D) network from 1 while 3 has one-dimensional (1D) chain structure. Complex 4 is a three-dimensional (3D) framework with CdSO 4 topology. The thermal stability and adsorption property of the complexes were investigated. Furthermore, it was found that complexes 1 – 4 can catalyze acetalization reaction of aldehydes with methanol, and 1 gives the highest yield.