CONNECTING QUANTUM STATE-RESOLVED SCATTERING DATA DIRECTLY TO CHEMICAL-KINETICS - ENERGY-TRANSFER DISTRIBUTION-FUNCTIONS FOR THE COLLISIONAL RELAXATION OF HIGHLY VIBRATIONALLY EXCITED MOLECULES FROM STATE-RESOLVED PROBES OF THE BATH

An energy transfer probability distribution function, P(E,E'), for the collisional relaxation of a highly vibrationally excited donor molecu le (C6F6, pyrazine) is constructed for the first time from experimenta l data on the bath (CO2) energy gain. A prescription for mapping bath quantum state resolved data onto P(E,E') is described in detail. Analy sis of earlier experimental data allows a calculation of the high Delt a E = E-E' region (-7000 cm(-1) < E-E' < -1500 cm(-1)) of P(E,E') for the above systems. Comparison of the P(E,E') functions reveals that C6 F6 is a more efficient donor molecule than pyrazine, in agreement with previous experiments and trajectory calculations. In addition, resona nce like structures in the P(E,E') functions arising from long range f orce mediated, V-V excitation of the carbon dioxide nu(3) mode are dis cussed. These results indicate that accurate P(E,E') functions can be determined from experiments involving probes of the bath energy gain. This technique can be expected to provide stringent tests of current e nergy transfer theory and can, in principle, be used in conjunction wi th measurements of thermal kinetics to obtain energy dependent unimole cular rate constants, k(E). (C) 1997 American Institute of Physics.