Theoretical Study of Reaction Mechanisms for NCX (X = O, S) + C 2H2

Hsin Tsung Chen, Jia Jen Ho*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)


The reaction mechanisms for NCX (X = O, S) with C2H2 was studied theoretically. The possible reaction mechanisms of NCO + C 2H2 investigated in this study were categorized into five different pathways leading to the five possible final products: HCCO + HCN, HCCO + HNC, HNCO + C2H, HONC + C2H, and HC2NCO + H, labeled in order from P1 to P5, respectively. Similar calculations were also carried out for the NCS counterpart, and the energy barriers as well as the products were compared. Direct hydrogen abstraction is favored in the formation of HNCO instead of HOCN. In contrast, it is much easier to form HSCN rather than HNCS. There are two different paths for the oxazole/thiazole formation as an intermediate, and the order of energy barriers of these two paths is opposite in NCO and NCS. The product channel of HNCO/ HSCN + C 2H may be kinetically favored at higher temperature. Other product channels are consistent with the experimental prediction of the formation of initial short-lifetime NCO/NCS-C2H2 adducts which then undergo rapid transformation into the products.

Original languageEnglish
Pages (from-to)7004-7012
Number of pages9
JournalJournal of Physical Chemistry A
Issue number36
Publication statusPublished - 2003 Sept 11

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry


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