Journal of Chemical and Engineering Data, Vol.55, No.2, 871-875, 2010
Heat Capacity and Standard Thermodynamic Functions of a Fullerene Complex, ((CH(3))(3)Si)(12)C(60), over the Range from T -> 0 K to T=350 K
Low-temperature heat capacities of the crystalline fullerene complex ((CH(3))(3)Si)(12)C(60) have been measured by a precision adiabatic calorimeter over the temperature range from T = (6.5 to 350) 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(p,m)(0), enthalpy, H degrees(T) - H degrees(0), entropy, S degrees(T), and Gibbs energy, G degrees(T) - H degrees(0), of ((CH(3))(3)Si)(12)C(60)(cr) over the range from T --> 0 K to T = 350 K. The low-temperature (T < 50 K) dependence of the heat capacity was analyzed on the basis of Debye's heat capacity theory of solids and its fractal variant. Following that analysis, the characteristic temperatures as well as the fractal dimension were determined, and some conclusions about the structure topology were made. The standard entropy of format,ion at T = 298.15 K of ((CH(3))(3)Si)(12)C(60)(cr) was calculated. The standard thermodynamic properties of tested fullerene complex and previously Studied C(60) fullerite/fullerene complex (t-Bu)(12)C(60) were compared.