Theoretical study on the unimolecular decomposition of thiophenol

✍ Scribed by Ala'a H. Al-Muhtaseb; Mohammednoor Altarawneh; Mansour H. Almatarneh; Raymond A. Poirier; Niveen W. Assaf

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 567 KB
• Volume: 32
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/jcc.21852

✦ Synopsis

Abstract

The potential energy surface for the unimolecular decomposition of thiophenol (C~6~H~5~SH) is mapped out at two theoretical levels; BB1K/GTlarge and QCISD(T)/6‐311+G(2d,p)//MP2/6‐31G(d,p). Calculated reaction rate constants at the high pressure limit indicate that the major initial channel is the formation of C~6~H~6~S at all temperatures. Above 1000 K, the contribution from direct fission of the SH bond becomes important. Other decomposition channels, including expulsion of H~2~ and H~2~S are of negligible importance. The formation of C~6~H~6~S is predicted to be strong‐pressure dependent above 900 K. Further decomposition of C~6~H~6~S produces CS and C~5~H~6~. Overall, despite the significant difference in bond dissociation, i.e., 8‐9 kcal/mol between the SH bond in thiophenol and the OH bond in phenol, H migration at the ortho position in the two molecules represents the most accessible initial channel. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011