Thermochemistry on crystalline compounds bis-(n-dodecylammonium) tetrachlorometallates (n-C12H25NH3)2MCl4(s) (MÂ =Â Cu and Cd)

Crystalline (n-C12H25NH3)2CuCl4(s) and (n-C12H25NH3)2CdCl4(s) were synthesized. Chemical analysis, elemental analysis, and X-ray crystallography were applied to characterise the compositions and crystal structures of the two complexes. In accordance with Hess law, two thermochemical cycles were designed, and the enthalpy changes of the reactions of n-dodecylammonium hydrochloride with CuCl2·2H2O(s) and CdCl2·2.5H2O(s) were determined by an isoperibol solution-reaction calorimeter. Eventually, the standard molar enthalpies of formation of the title compounds were derived.