Qiu, J
1997
Dynamic Nuclear Polarization of Nitrogen-15 Benzamide
Hu, J.Z.; Zhou, J.; Yang, B.; Li, L.; Qiu, J.; Ye, C.; Solum, M.S.; Wind, R.A.; Pugmire, R.J. and Grant, D.M.
SOLID STATE: Nuclear Magnetic Resonance, 8:129-37(1997). Funded by US Department of Energy/Basic Energy Services and ACERC.
A N-15 dynamic nuclear polarization (DNP) experiment is reported in which a N-15 DNP enhancement factor of approximately 2.6 x 10² is obtained on free radical doped samples of 99% N-15 labeled benazmide. The free radicals BDPA (1:1 complex of alpha, gamma-bisdiphenylene-beta-phenylallyl with benzene) and DDPH (2,2 -Di (4 - tert - octylphenyl) -1-picrylhydrazyl) are used as dopants and the spin relaxation effects of adding these dopants are studied by means of changes in proton and nitrogen T1 values of the samples. The combination is solids of a very low natural abundance, 0.37%, a small gyromagnetic ration, and a log spin - lattice relaxation time for N-15 nuclei create severe sensitivity problems that, in large part, are ameliorated by the signal enhancement observed in the N-15 DNP experiment on samples containing free electrons.
Qiu, J
1997
Dynamic Nuclear Polarization of Nitrogen-15 Benzamide
Hu, J.Z.; Zhou, J.; Yang, B.; Li, L.; Qiu, J.; Ye, C.; Solum, M.S.; Wind, R.A.; Pugmire, R.J. and Grant, D.M.
SOLID STATE: Nuclear Magnetic Resonance, 8:129-37(1997). Funded by US Department of Energy/Basic Energy Services and ACERC.
A N-15 dynamic nuclear polarization (DNP) experiment is reported in which a N-15 DNP enhancement factor of approximately 2.6 x 10² is obtained on free radical doped samples of 99% N-15 labeled benazmide. The free radicals BDPA (1:1 complex of alpha, gamma-bisdiphenylene-beta-phenylallyl with benzene) and DDPH (2,2 -Di (4 - tert - octylphenyl) -1-picrylhydrazyl) are used as dopants and the spin relaxation effects of adding these dopants are studied by means of changes in proton and nitrogen T1 values of the samples. The combination is solids of a very low natural abundance, 0.37%, a small gyromagnetic ration, and a log spin - lattice relaxation time for N-15 nuclei create severe sensitivity problems that, in large part, are ameliorated by the signal enhancement observed in the N-15 DNP experiment on samples containing free electrons.