Journal of Physical Chemistry A, Vol.105, No.43, 9901-9911, 2001
Theoretical study on the mechanism of the (CHF)-C-1+NO reaction
The complex doublet potential energy surface of the CHFNO system is investigated at the QCISD(T)/6-311G(dfp)//B3LYP/6-311G(d,p) level in order to explore the possible reaction mechanism of (CHF)-C-1 radical with NO. Twenty-six minimum isomers and fifty-nine transition states are located. Various possible reaction pathways are probed. It is shown that five dissociation products P-1 HF + NCO, P-2 F + HNCO, P-4 OH + FCN, P-5 F + HOCN, and P-7 (NH)-N-3 + FCO are both thermodynamically and kinetically accessible. Among the five dissociation products, P-2 and P-4 may be the most abundant products with comparable quantities, whereas P-1 is much less competitive followed by the almost negligible P-5 and P-7. Our results are in marked difference from previous experimental observation that only two dissociation products P-1 and P-2 are identified with the branching ratio being 6:4. However, and despite some energetic differences, our calculated potential energy surface features are quite in parallel to those of the analogous reaction (CH2)-C-3 + NO that has been extensively studied. Therefore, future experimental reinvestigations are desirable to clarify the mechanism of the title reaction. The present study may be useful for understanding the CHF chemistry.