Thermodynamic properties of 3D copper(II)-MOFs assembled by 1H-tetrazole

Three-dimensional MOFs, {[Cu-3(tz)(4)Cl-2] 2CH(3)OH}(n) (Htz = 1H-1,2,3,4-tetrazole), have been synthesized in methanol. It was characterized by chemical analysis, element analysis, IR spectroscopy, single-crystal X-ray diffraction and thermal analysis. Thermogravimetric analysis demonstrated that the MOFs after removing methanol molecules possessed good thermostability with decomposition temperature up to 533 K. The enthalpy change of liquid-phase formation reaction was determined by a RD496-2000 microcalorimeter at 298.15 K with the value of (-46.63 +/- 0.26) kJ mol(-1). The enthalpy change of solid-phase formation reaction was calculated as (-573.89 +/- 0.89) kJ mol(-1) on the basis of a designed thermochemical cycle. The thermodynamics of formation reaction of the MOFs was investigated by changing the temperature of liquid-phase reaction. Based on the experimental results, fundamental kinetic and thermodynamic parameters k, n, E, , and were obtained. The specific heat capacity at 298.15 K was determined to be (1.87 +/- 0.08) J K-1 g(-1) by a RD496-2000 calorimeter. In addition, the constant volume combustion energy of title MOFs was determined by a RBC-II rotating-bomb calorimeter at 298.15 K. The standard molar enthalpy of combustion and standard molar enthalpy of formation were calculated to be (-4736.43 +/- 4.03) kJ mol(-1) and (293.42 +/- 4.11) kJ mol(-1), respectively.