H-1 CRAMPS NMR DERIVED HYDROGEN DISTRIBUTIONS IN VARIOUS COAL MACERALS

The distribution of protons bonded to sp2 and sp3 hybridized carbons i n a number of macerals including liptinites and inertinites, has been investigated by C-13 cross polarization magic angle spinning (CP/MAS) and H-1 combined rotation and multiple pulse nuclear magnetic resonanc e spectroscopy (CRAMPS). Some preliminary H-1-C-13 solid state heteroc orrelation spectra of coals and one maceral have also been obtained. C RAMPS was only successful in resolving acidic, aromatic/alkenic, carbo hydrate and aliphatic protons in the macerals. The semifusinites had v ariable (0.38-->0.58) proton aromaticities and (0.40-->0.84) carbon ar omaticities, and the liptinite macerals had a low (0.06) fraction of p rotons attached to sp2 hybridized carbon. Of the nine resinite samples examined, one (Hornerstown) was clearly identified to be a naturally occurring polymer of styrene. The CRAMPS spectra of the other seven we re useful, identifying them as carboxylic acids. Two dimensional H-1-C -13 heteronuclear solid state spectroscopy was successful in resolving two types of aliphatic hydrogen in the selected coals studied, with l onger range coupling able to be observed in the structurally simpler H ornerstown resinite by implementation of two WIM-24 cross-polarization cycles.