Two Ni(II) Coordination Polymers Constructed with a Bent Connector: Crystal Structures and Magnetic Properties

Abstract

The hydrothermal reactions of a bent ligand, 1H-3,5-bis(4-pyridyl)-1,2,4-triazole (bpt), with Ni(II) ions as well as two carboxylate co-ligands yielded two new Ni(II) coordination polymers, {[Ni2(bptc)(bpt)2(H2O)2]·9H2O}n and [Ni(hb)2(bpt)2(H2O)]n (H4bptc = 3,3’,4,4′-benzophenone-tetracarboxylate acid, Hhb = p-Hydroxybenzoate acid). In the first complex, bptc acts as a μ4-bridge to link metal centres, forming a two-dimensional (2-D) layer architecture. The 2-D layer is further connected by bpt pillars to generate a 3-D non-interpenetrating open framework with a 4-connected 64.82 topology. A magnetic study revealed the occurrence of a weak ferromagnetic interaction within the Ni(II) centres. In the second complex, adjacent metal centres are connected by water molecules to furnish a metal–water chain, in which hb and bpt are both terminal ligands.