Heat capacities of thiane sulfones and thiane sulfoxide -: Refining of Cp group values for organosulfur compounds and their oxides

A thermophysical study of thiane sulfone, 1; 1,3-dithiane sulfone, 2; and 1,3-dithiane sulfoxide, 3 in the temperature intervals between T = 268 K and their respective melting temperatures has been carried out. The experimental values for the mole fraction, temperature, enthalpy and entropy of fusion and the associated standard deviation as determined by differential scanning calorimetry (DSC) are x = (0.9996 +/- 0.0001), T-fus = (370.8 +/- 0.1) K, Delta(fus)H(m) = (18.4+/-0.2) kJ mol(-1), Delta(fus)S(m) = (49.6 +/- 0.5) J mol(-1) K-1 for thiane sulfone, 1; x = (0.9994 +/- 0.0001), T-fus, = (414.0 +/- 0.2) K, Delta(fus)H(m) = (22.0 +/- 0.2) kJ mol(-1) Delta(fus)S(m) = (53.1 +/- 0.4) J mol-1 K-1 for 1,3-dithiane sulfone, 2; and x = (0.9977 +/- 0.0001), T-fus = (361.9 +/- 0.1) K, Delta(fus)H(m) = (22.6 +/- 0.2) kJ mol(-1), Delta(fus)S(m) = (62.4 +/- 0.5) J mol(-1) K-1 for 1,3-dithiane sulfoxide, 3. Heat capacities in those temperature intervals and in condensed state were measured and no additional solid-solid phase transitions were observed. The heat capacities at T = 298.15 K were used to refine group values for organosulfur compounds and their oxides. (C) 2003 Elsevier Science B.V. All rights reserved.