Thermodynamic properties of dicarbonyl rhodium o-semiquinonate complex whose crystals display photomechanical properties

In an adiabatic low-pressure calorimeter, the temperature dependence of the standard molar heat capacity of paramagnetic dicarbonyl rhodium complex with o-semiquinone (CO)2Rh(SQ) has been determined in the range from T = (6 to 355) K mainly with an accuracy of about 0.3%. Over the ranges from T = (205 to 234) K, T = (266 to 315) K and T = (316 to 345) K physical transformations have been revealed and their enthalpies and entropies have been estimated. The experimental data were used to calculate the thermodynamic functions Cp,m∘/R,Δ0THm∘/(R·K),Δ0TSm∘/R and Φm∘=Δ0TSm∘-Δ0THm∘/T (where R is the universal gas constant) between T = (0 and 355) K. The fractal dimension D in the heat capacity function of the fractal variant of Debye heat capacity theory has been evaluated.