Reactions Forming Electronically-excited Free Radicals

Alternative Title

Part 1. Ground-state reactions involving NF2 and NF radicals

Abstract

Atomic resonance absorption in the far vacuum ultraviolet and atomic resonance fluorescence have been used to investigate the kinetics of primary and secondary processes in the overall reaction of H 2S atoms with NF2 radicals from 298 to 550 K. Rate constants for the following elementary reactions have been determined directly [k298/cm 3 molecule-1 s-1 (1 σ)]: H + NF 2 →k1 HF + NF; k1 = (1.5 ± 0.2) × 10-11; O + NF2 →k5 NF + FO; k 5 = (1.8 ± 0.9) × 10-12; N + NF2 →k8 NF + NF; k8 = (3.0 ± 1.2) × 10 -12. The overall H + NF2 reactive system, containing H2, is characterised as a self-propagating chain reaction, in which the chain carriers are H, NF and F. Ground-state N 4S atoms are formed by the reaction H + NF, although these atoms play only a minor role in propagating the overall H + NF2 chain reaction. Computer modelling of the H and N atom profiles was used to obtain values for k4 and k2: H + NF →k4 HF + N; k4 = (2.5 ± 0.5) × 10-13; NF + NF →k2 N2 + 2F; k2 = (7.0 ± 3.5) × 10-11. Thus, the predominant decay channel for NF radicals is through rapid bimolecular disproportionation to give N2 + 2F.

Department(s)

Chemistry

International Standard Serial Number (ISSN)

0300-9238

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1980 Royal Society of Chemistry, All rights reserved.

Publication Date

01 Jan 1980

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