Thermodynamics of dimer fullerene complex [(Me3Si)3C60]2 in the range from 0 ⩽ T/K ⩽ 480

In the present work, firstly the temperature dependence of heat capacity Cp,m∘=f(T) of the crystalline fullerene complex [(Me3Si)3C60]2 has been measured between T = (6 and 350) K and T = (330 and 480) K by precision adiabatic vacuum and dynamic calorimetry, respectively. The irreversible endothermic effect was detected in the temperature range from T = (400 to 466) K and its thermodynamic characteristics have been determined and analysed. This transformation was caused by the opening of a dimeric bond between fullerene fragments and the decomposition of the tested complex on heating. The experimental data were used for calculating the standard (p∘ = 0.1 MPa) thermodynamic functions Cp,m∘/R, Δ0THm∘/RT, Δ0TSm∘/R and Φm∘/R=Δ0TSm∘/R-Δ0THm∘/RT (where R is gas constant) in the range 0  ⩽ T/K ⩽ 400. The value of the standard entropy of formation of the complex from simple substances at T = 298.15 K has been estimated.