Selective oxidation of PAH with RuO4 as a preliminary step in the characterization of polymerized pitches

Components of polymerized pitches are of large molecular size and consequen tly difficult to characterize. Moreover, pitches with similar degrees of po lymerization obtained by different treatments have similar properties brit different molecular structures. Selective oxidation with RuO4 has proven to be a suitable method for the elucidation of structural details in other co mplex carbonaceous substances such as coals, asphaltenes, or kerogens. In t his paper the behavior of some model compounds was studied in order to achi eve a better understanding of how this specific oxidation affects several p ossible pitch structures. To improve the efficiency of the reaction, an ult rasonic bath was used. Highly condensed compounds such as coronene and trip henylene were the most reactive, as they were the most oxidized of all the compounds tested. On the other hand, it was found that aryl-aryl bonds are very stable. The ability of RuO4 to distinguish between different molecular structures could be used as a new tool in the chemical characterization of polymerized pitches.