Temperature and density dependent solute vibrational relaxation in supercritical fluoroform

Temperature- and density-dependent vibrational relaxation data for the upsi lon (6) asymmetric stretch of W(CO)(6) in supercritical fluoroform (trifluo romethane, CHF3) are presented and compared to a recent theory of solute vi brational relaxation. The theory, which uses thermodynamic and hydrodynamic conditions of the solvent as input parameters, shows very good agreement i n reproducing the temperature- and density-dependent trends of the experime ntal data with a minimum of adjustable parameters. Once a small number of p arameters are fixed by fitting the functional form of the density dependenc e, there are no adjustable parameters in the calculations of the temperatur e dependence. (C) 2001 American Institute of Physics.