Thermal studies of chromium, molybdenum and ruthenium complexes of chloranilic acid

Chromium, molybdenum and ruthenium complexes of chloranilic acid (H2CA) were investigated by the thermogravimetric (TG) technique. The TG plot of Cr(H2CA)3 showed three decompositions in the temperature range 336–802°K. On the other hand, the TG plot of MoO3(HCA) complex displayed successive weight losses in four steps covering the temperature range 350–1278°K. The thermal decomposition of the cluster compound Ru3(CO)10(μ-H)(HCA) occurred in three steps within the decomposition temperature range 302–764°K. Calculation of the reaction order of decompositions of the three complexes revealed that they follow first-order kinetics. The thermodynamic parameters for the different decomposition steps of the complexes were also determined from their DTG plots.