Heat Capacity and Standard Thermodynamic Functions of Bis(η6-mesitylene)vanadium Fulleride [(η6-sim-Me3H3C6)2V]•+[C60]•- over the Range from T = (0 to 345) K

Low-temperature heat capacities of the crystalline bis(eta(6)-mesitylene)vanadium fulleride [(eta(6)-sim-Me3H3C6)(2)V](center dot+)[C-60](center dot-) have been measured by a precision adiabatic vacuum calorimeter over the temperature range from T = (7 and 345) K for the first time. The experimental results have been used to calculate the standard (P degrees = 0.1 MPa) thermodynamic functions: molar heat capacities C degrees(p,m), enthalpy H degrees (T) - H degrees (0), entropy S degrees (T), and Gibbs energy G degrees(T) - H degrees(0) of [(eta(6)-sim-Me3H3C6)(2)V](center dot+)[C-60](center dot-) over the range from T = (0 to 345) K The low-temperature (T < 50K) dependence of the heat capacity was analyzed on the basis of Debye's heat capacity theory of solids and its fractal variant. Following that, the characteristic temperatures as well as the fractal dimension were determined, and some conclusions about the structure topology were made. The standard entropy of formation at T = 298.15 K of [(eta(6)-sim-Me3H3C6)(2)V](center dot+)[C-60](center dot-) (cr) was calculated. The standard thermodynamic properties of tested fiffleride and previously studied C-60 fullerite were compared.