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The rate coefficients of the F+H2 and F+D2 reactions must be accurately known over a wide temperature range if the HF and DF chemical lasers are to be properly modeled. Although the pulsed and cw chemical lasers operate at elevated temperatures (500 to 2000 K), no absolute rate data exist for T≳400 K. Extension of the infrared multiphoton dissociation–infrared fluorescence technique permitted the following Arrhenius equations to be determined between 295 and 765 K: kF+H2=(1.3±0.25)×1014 exp[−(1182±100)/RT]; kF+D2=(6.4±2.2)×1013 exp [−(1200±142)/RT]; kF+H2/kF+D2=(2.1±0.8) exp[(18±250)/RT].

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The reaction of hydrogen atoms with NF2 was studied in a flow tube using pulsed KrF laser initiation of H2/NF2/Ar mixtures at 440 K. The quantum yield for NF(a) production from the 249 nm photolysis of NF2 was determined to be 0.10±0.05. Several important reactions in this system were investigated, and rate coefficients were determined at 440 K. A value of (1.03±0.20)×10−30 cm6/molecule2 s was obtained for the three-body recombination of F atoms with NF2 and Ar. Rate constants for the relaxation of HF(v=2) and HF(v=3) by NF2 are (9.7±1.0)×10−14 and (2.5±0.5)×10−13 cm3/molecule s, respectively. Study of the quenching of NF(a) by NF2 yields a rate coefficient of (2.7±1.0)×10−16 cm3/molecule s. Evidence is presented that indicates the disproportionation of NF(a) is three orders of magnitude slower than that of ground state NF. Modeling results are presented which agree well with experimental data.

The electronic-energy pooling reactions forming O2(1Σ) are of critical importance to the overall mechanism of the O2(1Δ)–I atom transfer laser. In this study, we report temperature-dependent rate coefficient data for O2(1Δ)+O2(1Δ)→k2O2(1Σ)+O2(3Σ) and O2(1Δ)+I(2P1/2)→k3O2(1Σ)+I. These data were obtained using a temperature-controlled kinetic flow tube equipped with computer-controlled spectroscopic diagnostics. The fundamental data reported are k2(T)/k2(295) = (3.5±1.5)exp(−780/RT) and k3(T)/k2(T) = (5.5±1.0)×103. Both rate-coefficient ratios are reported for the temperature range T = 259 to 353 K. The results are compared with earlier measurements of these processes.