ABSTRACT:The singlet potential energy surface of the [CFNO 2 ] system is investigated at the B3LYP and CCSD(T) (single-point) levels to explore the possible reaction mechanism of CF radical with NO 2 . The top attack of C-atom of CF radical at the N-atom of NO 2 molecule first forms the adduct isomer FCNO 2 1 followed by oxygen-shift to give trans-OC(F)NO 2 and then to cis-OC(F)NO 3. Subsequently, the most favorable channel is a direct dissociation of 2 and 3 to product P 1 FCO + NO. The second and third less favorable channels are direct dissociation of 3 to product P 2 FNO + CO and isomerization of 3 to a complex NOF. . .CO 4, which can easily dissociate to product P 3 FON + CO, respectively. The large exothermicity released in these processes further drives most of the three products P 1 , P 2 , and P 3 to take secondary dissociation to the final product P 12 F + CO + NO. Another energetically allowed channel is formation of product P 4 1 NF + CO 2 , yet it is much less competitive than P 1 , P 2 , P 3 , and P 12 . The present calculations can well interpret one recent experimental fact that the title reaction is quite fast yet still much slower than the analogous reaction CH + NO 2 . Also, the results presented in this article may be useful for future product distribution analysis of the title reaction as well as for the analogous CCl and CBr reactions.