Proton-Transfer Mechanism in 2-Thioxoimidazolidin-4-one: A Competition between Keto/Enol and Thione/Thiol Tautomerism Reactions

• Setodeh Bagheri

  Department of Chemistry, Faculty of Science, University of Sistan and Baluchestan

• Hossein Roohi

  Department of Chemistry, Faculty of Science, University of Sistan and Baluchestan

抄録

The proton transfer in 2-thioxoimidazolidin-4-one (1,3-IM) via two keto/enol and thione/thiol intramolecular mechanisms was investigated by using DFT (B3LYP) and ab initio (MP2) methods in the gas phase. A conspicuous consistency was found between results of B3LYP and MP2 calculations. The change in structural parameters for direct keto/enol tautomerization is greater than thione/thiol transformation on going from ground state to transition state. At both level of calculations, the computed energy barrier for direct and water-assisted keto/enol tautomerization is higher than the corresponding thione/thiol. The energy barriers for direct proton-transfer tautomerization reactions are significantly greater than H2O-assisted tautomerization. The NBO results show that the change of electronic charge of hydrogens involved in migration in direct proton transfer is much greater than in the water-assisted mechanism.

収録刊行物

• Bulletin of the Chemical Society of Japan

  Bulletin of the Chemical Society of Japan 82 (4), 446-452, 2009-03

  Oxford University Press (OUP)

キーワード

• General Chemistry

詳細情報

• CRID: 1360002219105313920
• NII論文ID: 130004152586
• DOI: 10.1246/bcsj.82.446
• ISSN: 13480634
• ISSN: 00092673
• Web Site: https://academic.oup.com/bcsj/article-pdf/82/4/446/56270267/bcsj.82.446.pdf
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