OXYCYCLICS: UNDERSTANDING CATALYZED OXIDATION MECHANISMS IN BITUMEN AND OTHER PETROLEUM PRODUCTS

Abstract

Oxidation of organic molecules at low temperature covers a broad spectrum of chemical reactions ranging from the formation of simple alcohols to complex stereospecific rearrangements characteristic of some biological enzyme catalyzed events. The combination of mechanisms used to explain these many reactions is equally diverse, and sometimes difficult to justify. This paper attempts to pull these many ideas together into one simple, unified theory, not by looking at each individual mechanistic step, but rather by viewing the net chemical oxidation reaction as a series of two or more cyclic steps which follow reasonable pathways based upon our current knowledge of chemistry. Individual steps in this pathway may be heterolytic, homolytic, or perhaps even combinations of the two. It still may be appropriate to speak of electron transfer, free-radicals, electron pairs, back-bonding, and a myriad of other individual mechanistic events. However the concept of an oxycyclic reaction places certain restrictions on these individual interactions which seem to be supported by a broad spectrum of experimental evidence. For example, oxycyclica can consistently predict unexpected events such as epoxide ring formation, hydride and other anionic shifts, intermolecular oxygen transfer, stereospecific oxidations, anhydride formation, metal oxidation and reduction, and even the destruction of carbon-carbon sigma bonds--all events that would normally be considered quite unusual for ambient temperature reactions of any kind, Numerous oxidation reactions in asphalt such as sulfoxide, ketone and anhydride formation and metal catalyzed oxidations will be analyzed.