In this project in the Physical Chemistry program of the Chemistry Division, Professor George W. Flynn of Columbia University will continue his investigations on the energy transfer and quenching in highly vibrationally excited molecules at the microscopic, quantum state-resolved level. Using diode laser techniques developed by him, Prof. Flynn will study collisional reactions on a time scale of the duration of a single collision, these involving the vibrational and rotational, as well as translational degrees of freedom. Among the specific problems to be attacked are the determination of the characteristics of the donor molecules that lead to supercollisions, i.e., collisions in which large amounts of vibrational energy are transferred; of the changes in angular momentum which occur in these processes; and how the mass and other properties of the acceptor molecules affect the energy transfer. Also to be investigated are the quenching of electronically excited molecules, hot atom collisions and chemical reaction processes. Among the outstanding problems in contemporary physical chemistry are the details of chemical reaction processes. To this end it is necessary to investigate how molecules excited to high vibrational and rotational energies behave when they undergo collisions with other molecules. Since reacting molecules usually follow one of several possible reactions paths that lead to different reaction products, a detailed understanding of the transfer of vibrational, rotational, and translational energies among the collision partners and the reaction products is desirable, and necessary, in order to develop theoretical models that can lead to the control of reactions so as to yield a desired product with maximum yield. Not only do such studies yield data which can be compared conveniently to theoretical calculations, they also provide rather definite evidence for the mechanism or forces which control reaction processes. In addition, much of the experimental data to be obtained will be of practical interest in the study and control of unimolecular and bimolecular chemical reactions and photochemistry. These processes are of importance in the development of advanced materials and processing techniques necessary for improved microelectronic devices, the development of new, more efficient laser devices, and in the development of an improved understanding of atmospheric chemical reactions and environmentally important chemistry.
