Direct Observation of NF(X) Using Laser Induced Fluorescence: Determination of H + NF(2) Branching Ratio

For the first time, the branching ratio for the H + NF2 has been measured using direct detection of the excited NF a(1) delta and the ground NF(X3 delta -) states. NF a(1) delta was observed by its emission at 874 nm from both the 249 nm photolysis of NF2 and from the reaction of H atoms (produced from HBr photolysis at 193 nm) with NF2. While NF X3 delta - was easily detected by laser induced fluorescence on the NF b(1) delta - X3 delta - transition following 249 nm NF2 photolysis, it was no observed following the H + NF2 reaction. This result leads to a lower limit for the NF(a) branching ratio, NF(a)/NF sub tot 0.90 + or - 0.03, in accord with previous results. The measured NF a(1) delta quantum yield from KrF photolysis of NF2, (Theta)NF(a) 0.04 + or - 0.02 also agrees with prior work. The NF2 photolysis quantum yield is observed to be unity, based on results from an HC1 titration of the F atoms from the 249 nm photolysis of NF2.