Standard Thermodynamic Functions from Experimental Heat Capacity Measurements of Two Polycyclic Aromatic Hydrocarbons, Indeno[1,2,3-cd]pyrene and Benzo[ghi]perylene

Temperature dependencies of heat capacity of two polycyclic aromatic hydrocarbons, indeno[1,2,3-cd]pyrene and benzo[ghi]perylene, in a crystalline state were investigated using adiabatic calorimetry at T = 6.1 to 325.2 K and at T = 5.7 to 329.1 K, respectively. Smoothed molar heat capacity, C-p, m(o) (T), values at T = 0 to 320 K are presented along with values for the standard thermodynamic functions: molar third-law entropy, S-m degrees, Gibbs energy, [G(m)degrees(T) - G(m)degrees(0)], and enthalpy, [H-m degrees(T) - H-m degrees(0)]. Using the Cp, mo (T) data, the standard molar third-law entropies at T = 298.15 K, Smo, are calculated as 273.3 +/- 1.9 .K-1 mol(-1) for indeno[1,2,3-cd]pyrene and 278.6 +/- 1.7 J_K-1 mol(-1) for benzo[ghi]perylene. It was shown that the relative expanded uncertainties for thermodynamic functions in this work are lower compared to previously published data.