Thermodynamic properties of trans-tetrachlorodi-μ-carboxylate dirhenium(iii) complexes

Abstract

In order to obtain unknown thermodynamic properties, such as enthalpy of formation, of trans-tetrachlorodi-μ-carboxylate dirhenium(III) (trans-[Re₂Cl₄(RCOO)₂] (R = C₂H₅; C₃H₇; (CH₃)₂CH; (CH₃)₃C)) exothermic reactions of burning in oxygen were investigated. The products of burning were studied by chemical analysis. The experimental enthalpy changes of the burning reactions of the complexes were obtained from DTA curves. The standard enthalpies of formation for trans-[Re₂Cl₄(RCOO)₂] (R = C₂H₅; C₃H₇; (CH₃)₂CH; (CH₃)₃C) were found to be 36 966, 63 531, 48 701 and 66 350 kJ mol⁻¹ according to the second law of thermochemistry (Hess’s law). The enthalpies of formation for the trans-carboxylates of dirhenium(III) were calculated by a semiempirical method. A series of thermal stabilities for trans-tetrachlorodi-μ-carboxylate dirhenium(III) complexes was built by considering their thermodynamic properties.