This research, supported by the Experimental Physical Chemistry program, uses nuclear magnetic resonance techniques to obtain experimental information on the angle-dependent interaction between molecules by making measurements of nuclear spin relaxation times in dilute mixtures of gases. These measurements will provide directly the cross sections for transfer of rotational angular momentum. The molecules to be studied are important constituents in the atmosphere, the interstellar medium, flame systems and infrared lasers. In addition to the gas phase studies, changes in chemical shifts and the relaxation times due to collisions with paramagnetic species will be studied. Platinum atoms and paramagnetic transition metal complexes on solid supports will provide the paramagnetic centers. Nuclear magnetic resonance studies of mobile species on zeolites and other classes of molecular sieves will also be attempted.
