Hydrothermal synthesis of novel cobalt–organic framework, involving in-situ ligand transformation, DFT calculation, spectroscopic and thermal studies

Abstract

The novel 1-D polymeric compound, namely {[(H2O)3(2,2′-bpy)Co(μ2-oxo-bpdc)Co(H2O)3](NO3)2·2H2O}n, where bpdc is 2,2′-bipyridine-3,3′-dicarboxylate, bpy is bipyridine ligand has been hydrothermally synthesized. X-ray single crystal structural analysis revealed that in-situ transformation of 1,10-phenanthroline-5,6-dione (phendione) into bpdc2− occurs under hydrothermal treatment. This coordination polymer exhibited one-dimensional chains with side branches. Thermal stability of coordination polymer was investigated by thermo gravimetric analysis (TGA). A feasible mechanism for in-situ generation of bpdc2− ligand will also be provided. Density functional theory (DFT) calculations were also performed to understand the electronic structure of the compound from theoretical point of view. The electronic spectrum of title compound was analyzed and the absorption bands were assigned through the DFT/TDDFT procedures.