Direct observation of NF(X) using laser induced fluorescence - NF ground state vibrational kinetics and determination of the H + NF2 branching ratio
Abstract
The gas phase kinetics of the NF(X 3Sigma/-/) ground state radical have been investigated by direct observation for the first time. NF(X 3Sigma/-/) was produced from the KrF laser photolysis of NF2 and was directly monitored in the gas phase using laser induced fluorescence via the NF b1Sigma - X 3Sigma(-) transition. The extremely hot nascent NF(X 3Sigma/-/) vibrational distribution, T(vib) = 2350 K, was exploited to investigate vibrational relaxation with CO2 and SF6. While CO2 proved to be inefficient for NF(X) vibrational relaxation, SF6 is a rapid quencher. In order to study the branching ratio of the H + NF2 reaction, HBr was photolyzed using an ArF laser in the presence of NF2. Although NF a1-Delta was observed by its 872 nm emission, no NF(X) produced from this reaction was detected. This result leads to a lower limit for the NF(a) branching ratio of 0.99.
- Publication:
-
AIAA, Thermophysics, Plasmadynamics and Lasers Conference
- Pub Date:
- June 1988
- Bibcode:
- 1988tpl..confQ....H
- Keywords:
-
- Excimer Lasers;
- Ground State;
- Laser Induced Fluorescence;
- Molecular Oscillations;
- Molecular Relaxation;
- Nitrogen Fluorides;
- Carbon Dioxide;
- Krypton Fluoride Lasers;
- Photolysis;
- Photomultiplier Tubes;
- Radiative Lifetime;
- Atomic and Molecular Physics