A temperature dependence of 13C CPMAS NMR was measured for revealing the local electron spin structure in [Rh2(acam) 4Cl]n (Hacam=acetamide), Observed two sharp peaks were assigned to carbons of crystallographycally nonequivalent CH3 groups and a broad one to C in the C=O group. A large high-field shift of -125 ppm was observed in C (C=O), indicating a negative spin polarization on this carbon. From the temperature dependence of Fermi contact shifts, the hyperfine coupling constant of each carbon was determined. By considering hyperfine coupling constants, it is found that a marked amount of electron spins are distributed on C (C=O) with the negative polarization, and a small positive spin exists even on the terminal carbons in methyl groups. 1H MAS NMR spectra can be explained by the superposition of different shift lines, implying that spin polarization is also generated on hydrogen atoms.
|Number of pages||6|
|Journal||Molecular Crystals and Liquid Crystals Science and Technology Section A: Molecular Crystals and Liquid Crystals|
|Publication status||Published - 2002|
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics