Sulphur‐33 nuclear magnetic resonance of oxidized petroleum asphaltene

Publisher Website
Google Scholar
Abstract
A 33S NMR spectrum has been obtained from an asphaltene sample for the first time. Asphaltene from the Athabasca tar sands bitumen, Alberta, Canada, was oxidized with RuVIII, which selectively converts sulphide sulphur into the corresponding sulphone. The 33S NMR spectrum of this sample at 30.7 MHz featured a broad signal centred at 320 ppm downfield from CS2. The width of this signal was too broad, owing to the quadrupole relaxation of the nuclei in the solution and/or the many types of sulphone molecules, to permit the assignment to any particular sulphone types. This situation was not improved by the use of proton broad band decoupling at elevated temperatures. Nevertheless, the mere presence of the aliphatic sulphones provides the first unambiguous evidence for the presence of aliphatic sulphides in a petroleum asphaltene. Similar results were obtained from sulphones prepared by peroxide oxidation of high molecular weight sulphides isolated from bitumen from the Wabasca, Alberta deposit.