Determination of the spin density distribution in the organic conductor DMTM(TCNQ)_2 with ~13C magic angle spinning NMR

摘要

~13C magic angle spinning (MAS) NMR experiments on the organic conductor N,N-dimethyl- thiomorpholinium bis-tetracyanoquino-dimetrhane [DMTM(TCNQ)_2] isotopically enriched at the position of the C-2 carbons of TCNQ are reported. Two isotropic resonances are resolved above the structural phase transition at 272 K, both exhibiting large positive isotropic and anisotropic Knight shifts. Sideband analysis of the MAS SPECTRA HAS YIELDED THE COMPLETE Knight shift tensors above T_c, in the insulating state.