ONE-DIMENSIONAL AND 2-DIMENSIONAL AL-27 MAS-NMR STUDY OF BASIC ALUMINUM SULFATE

The quadrupole coupling constants (QCC) and asymmetry parameters (eta) of the fourfold and sixfold coordinated Al sites in basic aluminum su lfate have been determined by using the field dependent second order q uadrupole shift, 2-dimensional nutation nuclear magnetic resonance and computer simulation. The quadrupole data from these three methods are consistent. The fourfold coordinated Al site has a QCC of 1.6 MHz and 0 less than or equal to eta less than or equal to 0.22, while the 12 sixfold coordinated Al sites have an average QCC of 5.5 MHz and an 0 l ess than or equal to eta less than or equal to 0.2.