Femtochemistry at high pressures. The dynamics of an elemantary reaction in the gas—liquid transition region
An extension of femtochemistry to the gas—liquid transition region is reported for an elemantary reaction, the dissociation and recombination of iodine in supercritical argon reaching a density of 30.5 mol ℓ^(−1). Three phenomena are systematically studied in the range 0 to 2000 bar of argon: the change of the coherent nuclear motion with solvent density, the rate of predissociation, and the caging by the solvent. The approach offers a unique way for examining the dynamics in real time from the gas to the liquid density limit.