Thermochemical studies on complex of [Sm(o-NBA)3phen]2

A ternary complex [Sm(o-NBA)3phen]2 (o-NBA: o-Nitrobenzoate; phen: 1,10-phenanthroline) was synthesized and characterized by elemental analysis, IR, molar conductance, and thermogravimetric analysis. The dissolution enthalpies of SmCl3·6H2O(s), o-HNBA(s) and phen·H2O(s) in mixed solvent (VHCl :VDMF:VDMSO=2:2:1) were determined by calorimetry at 298.15 K. The enthalpy change of the reaction was determined to be ΔrHθm=252.49±1.60 kJ/mol. Using the relevant data in the literature and a thermochemical recycle according to Hess's Law, the standard molar enthalpy of formation of [Sm(o-NBA)3 phen]2 (s) was estimated to ΔfHθm=−4109.2±7.3 kJ/mol.