Laser-induced reactions of hexafluorobenzene and selected hydride compounds

Infrared-laser-induced reactions between C6F6 and general hydrides R-H (R = H, D, CH3, HC triple bond C, H2C double bond CH, and Cl) were studied by irradiating C6F6 at 1027 cm-1 in C6F6/R-H mixtures. In general, two competitive pathways involving C-F bond cleavage in C6F6 were observed as follows: (1) C6F6 + R-H → C6F5H + R-F and (2) C6F6 + %-H → C6F5R + HF. C6F6 decomposition also took place to a minor extent depending on the mole fraction of C6F6 and gave rise to C2F4 and C2H2. When D2 was used C6F5D was the major product. C6F5H was the major product in the reactions involving H2 and C2H2. Besides C6F5H, other monosubstituted products derived from C6F6 were also formed, generally within 20-100 pulses. Thus, C6F5CH3, C6F5CH double bond CH2, CH2, C6F5C triple bond CH, and C6F5Cl were produced, respectively in the reaction of C6F6 with CH4, C2H4, C2H2, and HCl. In the first and last cases these products were the major ones observed. The results are discussed mechanistically in terms of the initial formation of the C6F5 radical and synthetically in terms of the utility of obtaining selective laser-induced reduction of C6F6