title: Theoretical study on the unimolecular decomposition of thiophenol.
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.
authors.affiliation: Department of Chemical Engineering, Al-Hussein Bin Talal University, Ma'an-Jordan.
authors.forename: Ala'a H
authors.initials: AH
authors.lastname: Al-Muhtaseb
authors.forename: Mohammednoor
authors.initials: M
authors.lastname: Altarawneh
authors.forename: Mansour H
authors.initials: MH
authors.lastname: Almatarneh
authors.forename: Raymond A
authors.initials: RA
authors.lastname: Poirier
authors.forename: Niveen W
authors.initials: NW
authors.lastname: Assaf
mesh_terms: D017554:Carbon Compounds, Inorganic / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D008962:Models, Theoretical; D010636:Phenols / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry*; D013696:Temperature; D013816:Thermodynamics
chemical_list: D017554:Carbon Compounds, Inorganic; D010636:Phenols; D013438:Sulfhydryl Compounds; D013440:Sulfides; C092035:carbon sulfide; C042983:thiophenol