Wind R A, Zumbulyadis N, Young R H, Hung Y, Li L, Nuttall R H, Maciel G
Department of Chemistry, Colorado State University, Fort Collins 80523.
Solid State Nucl Magn Reson. 1992 Jun;1(2):55-65. doi: 10.1016/0926-2040(92)90017-4.
We have investigated the EPR and DNP behavior of a molecularly doped polymer modeling those used to transport electronic charge in electrophotography. The EPR spectra show no evidence of the superexchange reported for a closely related system based on tri-p-tolylamine. The difference may be due to larger charge-transfer matrix elements in the latter system. An unambiguous interpretation of the observed 1H DNP was rendered difficult by the unanticipated asymmetry of the EPR spectra. We report extensive data on the "three-spin" effect evident in the DNP-enhanced 13C NMR spectra, and comment on its potential for characterizing polymer interfaces.
