WSOLIDS1: MAS: Quadrupolar nucleus [ Go Home ]

This squeezed picture shows an example for the succesful simulation of a MAS spectrum of a quadrupolar nucleus that shows the combined effect of quadrupolar interaction and spin-spin coupling to a spin-1/2 nucleus in a powder sample. It is the ⁹⁵Mo NMR MAS spectrum of pentacarbonyl-5-methyldibenzophosphole molybdenum(0), Mo(CO)₅(MeDBP), and the results have been published in:

K. Eichele, R. E. Wasylishen, J. H. Nelson:
Solid-State ⁹⁵Mo NMR Studies of Some Prototypal Molybdenum Compounds: Sodium Molybdate Dihydrate, Hexacarbonylmolybdenum, and Pentacarbonyl Phosphine Molybdenum (0) Complexes.
J. Phys. Chem. A 1997, 101, 5463-5468.

Click on the picture to have a better look.

Background

If the nuclear quadrupolar coupling for a quadrupolar nucleus is sufficiently large, MAS cannot remove its effect on the line shape of the central transition and causes second-order broadening with characteristic lineshapes as well as a second-order shift. In order to obtain correct chemical shifts for the quadrupolar nucleus, simulation of the spectra is required. Optionally, indirect coupling to a heteronucleus can be added (note: quadrupolar interaction, if any, is neglected for the coupled heteronucleus).

[ Go Home ] | last modified: 16.08.2001