Solubility of I2(s) and equilibrium concentration of the (I2+C6H6) charge transfer complex in supercritical xenon with added C6H6

The solubility of I-2(s) in supercritical xenon with and without added C6H6 has been measured at the temperatures T = (300.79 +/- 0.04)K and (318.70 +/- 0.02)K over the pressure range from 5 MPa to 10 MPa. The u.v. absorbance due to the charge transfer interaction between I-2 (acceptor) and C6H6 (donor) was also measured when the fluid was saturated, and also when unsaturated, with I-2. The enhancement of the solubility of I-2(s) due to added C6H6 was moderate, supporting the view that the charge transfer process does not contribute significantly to the thermodynamic properties of donor and acceptor. The effect of density on the equilibrium concentration quotient for the formation of the donor-acceptor complex is discussed. (C) 1997 Academic Press Limited.