Abstract
In order to understand the nature and mechanisms of deposit formation in Induction System Deposit (ISD), reactions between benzothiophene oxides and benzothiophenes were carried out under reflux conditions, using carbon tetrachloride as solvent. Samples of the reaction mixture were taken at different intervals during two weeks, and identification was made by pyrolisis/ gas chromatography/ mass spectrometry (P/GC/MS). In the first sample taken after 12 hr of testing, the formation of high molecular weight sulfur compounds was observed. These compounds were identified as naphthobenzothiophenes, methyl and dimethyl naphthobenzothiophenes, phenylbenzothiophen and dinaphthobenzothiophenes. Mechanisms of formation are proposed and the new intermediate compound is identified