Phase equilibria in the C-60-sulphur system

A study of the C-60-S system in the 220-773 K range revealed the existence of only one molecular compound, monoclinic C-60. 2S(8), that melts peritect ically at 543 K (Delta(pi)H = + 54 J g(-1)). Although C-60. 2S(8) forms wit h a negative excess volume, the enthalpy associated with its desulphuration is close to that of the sublimation of pure sulphur. The molar fractions o f the peritectic and eutectic liquids were found to be x(Ss) = 0.988 (543 K ) and 0.992 (385 K), respectively. (C) 1999 Elsevier Science B.V. All right s reserved.