Low-temperature molar heat capacities, thermodynamic properties and crystal structure of Cu(C3N2H4)4(ClO4)2

A complex of copper perchlorate coordinated with imidazole Cu(C3N2H4)(4)(ClO4)(2) was synthesized and characterized by X-ray single-crystal diffraction. The complex is centrosymmetric in the monoclinic P2(1)/c space group. The low-temperature molar heat capacities and thermodynamic properties of the complex were studied with adiabatic calorimetry (AC). The thermodynamic functions [H-T-H-298.15] and [S-T-S-298.15] were derived in the temperature range from 80 to 370 K with temperature interval of 5 K. Thermal decomposition behavior of the complex in nitrogen atmosphere was studied by thermogravimetric (TG) analysis and differential scanning calorimetry (DSC). The mechanism of the decomposition was deduced to be the breaking up the two Cl-O bonds of the Cl-O-Cu and the Cu-N bonds of the imidazole rings in succession.