Electron spin density distribution in the polymer phase of CsC60: assignment of the NMR spectrum.

We present high resolution 133Cs-13C double resonance NMR data and 13C-13C NMR correlation spectra of 13C enriched samples of the polymeric phase of CsC60. These data lead to a partial assignment of the lines in the 13C NMR spectrum of CsC60 to the carbon positions on the C60 molecule. A plausible completion of the assignment can be made on the basis of an ab initio calculation. The data support the view that the conduction electron density is concentrated at the C60 "equator," away from the interfullerene bonds.

Isotropic mixing, sign discrimination, and sensitivity in solid-state wideline heteronuclear correlation experiments.

A variant of the solid-state wideline heteronuclear NMR correlation experiment is described which overcomes some of the drawbacks associated with the routine experiment. The modified experiment results in spectra which are sign-discriminated in the omega(1) dimension, but without the loss in sensitivity expected for a standard hypercomplex implementation. In favorable cases sensitivity enhancements over comparable routine experiments are obtained. As well as these advantages, the method retains the selectivity of modified WISE experiments proposed previously which give spectra containing correlations between directly bonded nuclei only.