CHANGES OF MOLAR VOLUME FROM SOLID TO LIQUID AND SOLUTION - THE PARTICULAR CASE OF C-60

摘要

Partial molar volumes of solid C-60 at infinite dilution have been determined from high precision density measurements in 12 organic solvents characterized by different physicochemical properties and solubilizing capacity. Results appear unusual with respect to almost all organic solid substances in that not only are the values far smaller than the estimated molar volume of liquid C-60 but they even remain lower than the molar volume of the pure solid C-60. The results which range from 350 to 440 cm(3) mol(-1) reveal the non-uniform behavior of this remarkable rigid molecule in solution. Although no readily obvious relationship between the partial molar volumes of C-60 in a particular solvent and properties of the solvent has been found, the observed rough dependence on the molar volume of the solvent might be interpreted in terms of the arrangement of the molecules differing in size and shape, and how they fit together in solution.