Theoretical study on the mechanism of the (CHF)-C-1+NO reaction

The complex doublet potential energy surface of the CHFNO system is investi gated at the QCISD(T)/6-311G(dfp)//B3LYP/6-311G(d,p) level in order to expl ore the possible reaction mechanism of (CHF)-C-1 radical with NO. Twenty-si x minimum isomers and fifty-nine transition states are located. Various pos sible reaction pathways are probed. It is shown that five dissociation prod ucts 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 f ive dissociation products, P-2 and P-4 may be the most abundant products wi th 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 fro m previous experimental observation that only two dissociation products P-1 and P-2 are identified with the branching ratio being 6:4. However, and de spite some energetic differences, our calculated potential energy surface f eatures are quite in parallel to those of the analogous reaction (CH2)-C-3 + NO that has been extensively studied. Therefore, future experimental rein vestigations are desirable to clarify the mechanism of the title reaction. The present study may be useful for understanding the CHF chemistry.