Professor T.S. Lin is supported by a grant from the Experimental Physical Chemistry Program for the application of pulsed electron paramagnetic resonance spectroscopy. This technique will be used to study the mechanisms of spin polarization transfer from electron spins to nuclear spins (Dynamic Nuclear Polarization processes) which invoke the photo-excited triplet states of organic solids. Three aspects will be investigated: resonance polarization transfer via the integrated solid effect, coherent polarization transfer via the spin locking experiment, and electron-nuclear cross polarization dynamics at the level anticrossing region. The results of these studies are expected to provide the information which will allow formulation of a theory of the resonance polarization transfer and the cross polarization processes in general. %%% The enhancement of the proton nuclear magnetic resonance signal in some organic solids can be as high as a factor of 15,000 compared to the normal signal. Such a large improvement in the intensities of the proton signals could allow the studies of structures of guest molecules at low concentrations in these crystals.
