Radical Pathways of Coal Dissolution in Donor Media During Reactions of Coals and Specifically Deuterated Tetralin

摘要

Recent studies utilizing deuterium labelling to trace the pathways of hydrogen transport between donor solvent, coal, and model compounds provided a detailed understanding of mechanistic pathways operating at the molecular level during coal dissolution in donor media. Deuterium scrambling in donor solvents constitutes a sensitive probe of the structural features of coal and mineral matter. In previous papers we presented detailed information concerning the time dependence of the structural distribution of deuterium transferred to a subbituminous coal at 427 exp 0 C in tetralin-1,1-d sub 2 . In a preliminary report of our recent studies of high temperature reactions of specific radicals in the tetralin and alkylindan systems we presented evidence that 2-tetralyl as well as 1-tetralyl radical is formed during the oxidation of tetralin to naphthalene. The evidence for the intermediacy of 2-tetralyl was the observation of scrambling of deuterium from the 1- to the 2-position of tetralin during reaction with coal. In this paper we present a study of the scrambling and depletion of deuterium in reactions of a bituminous and a subbituminous coal with tetralin-1,1-d sub 2 . Radical and ionic pathways responsible for major differences in scrambling rates for the two coals are discussed.