Derivatographic Studies on Transition Metal Complexes. I. Deaquation-Anation Reaction of Aquopentaamminechromium(III) Complexes

Abstract

By using a Derivatograph, the simultaneous analyses in TGA, DTA and DTG on the several aquopentaamminechromium(III) complexes were attempted. The enthalpy changes, ΔH, in the deaquation-anation processes of aquopentaamminechromium(III) nitrate, chloride, bromide, iodide, sulfate and sulfite were calculated as 11.9, 6.1, 9.0, 10.8, 13.8 and 12.8 kcal/mol, respectively, the activation energies, E^\eweq, in the corresponding processes of the nitrate, chloride, bromide, sulfate and sulfite were obtained by the DTG curve analysis as 18, 28, 38, 36 and 33 kcal/mol, and those in the nitrate, chloride, bromide, iodide, sulfate and sulfite were obtained by the DTA curve analysis as 14, 25, 36, 19, 39 and 32 kcal/mol, respectively.