Inertinite aromaticities

The elemental composition of the three maceral groups varies. The vitrinite, which frequently is about 85% of the sample in the United States, is similar to the patent coal. The liptinites are richer in hydrogen, whereas the inertinites are relatively deficient in hydrogen and richer in carbon. The liptinites also contain more aliphatic materials the inertinites are richer in aromatics. The term inertinite refers to the relative chemical inertness of this material, making it especially undesirable for Hquefaction processes because it tends to accumulate in recycled feedstock streams. 

Inertinite radicals have very uniform g values, the magnitude of which suggests association with aromatic molecules. Radical densities can be extremely high (up to 25 x the levels seen in exinites). The linewidths are much narrower than in other maceral types ( l-2 Gauss vs 7 G for exinites and vitrinites), and both widths and shapes depend sensitively on the maceral "history", as reflected in atomic H/C ratios and the density. 

A g of 2.0029 for the inertinites reflects the aromatic character of the radicals and little, if any, heteroatom involvement. Exinites also are fairly tightly grouped, but g values of 2.0031 are more typical of molecules containing nitrogen. By... 

The rank dependence of the elemental composition of the maceral groups is shown in Fig. 9. The inertinites are the most aromatic, followed by the vitrinites and then the liptinites. Their oxygen contents decrease in the order vit-... 

---