Theoretical study on reaction mechanism of the CF radical with nitrogen dioxide

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 NOFCO 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. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1907–1919, 2001