Vibrational lifetimes and absorption spectra of the asymmetric CO stretching mode (similar to 1990 cm(-1)) of W(CO)(6) in supercritical CO2 are reported as functions of solvent density and temperature. Close to the critical temperature, the observables are density independent over a twofold range of density. Possible explanations are discussed for this unique behavior. (C) 1996 American Institute of Physics.