Reactions of NH radicals. 6. Reactions of NH(a/sup 1/. delta. ) with C/sub 2/H/sub 2/ and unimolecular decompositions of C/sub 2/H/sub 3/N*
Photolysis of HN/sub 3/ vapor in the presence of C/sub 2/H/sub 2/ was studied at 313 nm and 303 K. The products were N/sub 2/, H/sub 2/, CH/sub 4/, C/sub 2/H/sub 4/, C/sub 2/H/sub 6/, NH/sub 4/N/sub 3/, C/sub 4/H/sub 5/N/times/HN/sub 3/ (salt of C/sub 4/H/sub 5/N with HN/sub 3/), HCN, CH/sub 3/CN, and polymers. From the quantum yields of these products, measured as a function of the pressure of C/sub 2/H/sub 2/ or HN/sub 3/, the following mechanism for the main reactions was inferred: HN/sub 3/ + hv(313 nM) ..-->.. NH(a/sup 1/..delta..) + N/sub 2/; NH(a/sup 1/..delta..) + HN/sub 3/ ..-->.. 2N/sub 2/ + 2H (2a); NH(a/sup 1/..delta..) + HN/sub 3/ ..-->.. NH/sub 2/ + N/sub 3/ (2b); NH(a/sup 1/..delta..) + HN/sub 3/ ..-->.. N/sub 2/ + N/sub 2/H/sub 2/* (2c); NH(a/sup 1/..delta..) + C/sub 2/H/sub 2/ ..-->.. C/sub 2/H/sub 3/N* (CH/double bond/CH-NH (res) and CH/identical to/C-NH/sub 2/) (3); C/sub 2/H/sub 3/N* ..-->.. CH/sub 3/ + CN (4); C/sub 2/H/sub 3/N* ..-->.. H + C/sub 2/H/sub 2/N (5); C/sub 2/H/sub 3/N* ..-->.. C/sub 2/H + NH/sub 2/ (6). The rate constant ratios at 303 K are k/sub 3//k/sub 2/ = 1.2/sub 0/, k/sub 5//k/sub 4/ = 15/sub 7/, and k/sub 6//k/sub 4/ = 0.82. The efficiency of the insertion to give CH/identical to/C-NH/sub 2/ in reaction 3 was about 0.05 of that of the addition to form CH/double bond/CH-NH (res). The spin relaxation of NH(a/sup 1/..delta..) to NH(..xi../sup 3/..sigma../sup -/) by C/sub 2/H/sub 2/ and the collisional deactivation of C/sub 2/H/sub 3/N* were not found. The rearrangement from CH/double bond/CH-NH (res) to CH/sub 3/NH or CH/sub 3/CN and the unimolecular decomposition rates by the RRKM theory for reactions 4 and 6 were discussed. The relative and absolute rate constants were compared for the reactions of NH(a/sup 1/..delta..) with various reactants.
- Research Organization:
- Univ. of Osaka Prefecture (Japan)
- OSTI ID:
- 5992758
- Journal Information:
- J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 92:17; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400500* -- Photochemistry
ALKENES
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
DATA
DECOMPOSITION
ENTHALPY
ETHYLENE
EXPERIMENTAL DATA
HYDROCARBONS
INFORMATION
INFRARED SPECTRA
KINETICS
MATHEMATICAL MODELS
MEDIUM TEMPERATURE
NITROGEN COMPOUNDS
NUMERICAL DATA
ORGANIC COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PHYSICAL PROPERTIES
RADICALS
REACTION KINETICS
SPECTRA
THERMODYNAMIC PROPERTIES
YIELDS