Synthesis, Characterization, and Thermodynamic Study of the Solid State Coordination Compound Cu(Nic)2•H2O(s)

A novel compound-monohydrated cupric nicotinate was synthesized by the method of room temperature solid phase reaction and a ball grinder. FTIR, chemical and elemental analyses and X-ray powder diffraction techniques were applied to characterize the structure and composition of the complex. Low-temperature heat capacities of the solid coordination compound have been measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 400 K. A melting process occurred in the temperature range of 326-346 K in the heat capacity curve, and the melting point, molar enthalpy and entropy of the fusion were determined to be T-fus= (341.290 +/- 0.873) K, Delta H-fus(m)=(13.582 +/- 0.012) kJ.mol(-1), Delta S-fus(m)=(39.797 +/- 0.067) J.K-1.mol(-1). The experimental values of the molar heat capacities in the temperature regions of 78-326 K and 346-400 K were respectively fitted to two polynomial equations. The polynomially fitted values of the molar heat capacities and fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were calculated and tabulated at an interval of 5 K.