Synthesis, structural characterization and thermochemistry of copper pyridine 2,6-dicarboxylate trihydrate

Abstract

Copper pyridine 2,6-dicarboxylate trihydrate (Cu(H2DPC)(DPC)·3H2O) was synthesized. X-ray crystallography, chemical analysis, and elemental analysis were applied to characterize the structure and composition of the complex. Low-temperature heat capacities of the complex were measured with a small sample automated adiabatic calorimeter. The smoothed molar heat capacities and thermodynamic functions of the complex relative to the standard reference temperature 298.15K were calculated based on the fitted polynomial equation. A reasonable thermochemical cycle was designed, and the standard molar enthalpies of dissolution for the reactants and products of the synthesis reaction in a selected solvent were measured by an isoperibol solution-reaction calorimeter. Eventually, the standard molar enthalpy of formation of the title complex was calculated as −(2389.92±2.53)kJmol−1 by the Hess thermochemical cycle. In addition, the reliability of the designed thermochemical cycle was verified by UV–vis spectroscopy.