Absolute rate constants for the reaction of CN with CH sub 4 , C sub 2 H sub 6 , and C sub 3 H sub 8 from 292 to 1,500 K using high-temperature photochemistry and diode laser absorption

Journal Article · Thu Oct 31 04:00:00 EST 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100175a051· OSTI ID:7130973

Balla, R J; Casleton, K H ^[1]; Adams, J S; Pasternack, L ^[2]

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1. Morgantown Energy Technology Center, WV (United States)
2. Naval Research Lab., Washington, DC (United States)

By combining the laser-induced fluorescence detection technique with high-temperature reactor technology, absolute rate constants for the reaction of CN with CH{sub 4}, C{sub 2}H{sub 6}, and C{sub 3}H{sub 8} have been measured as a function of temperature (292-1,500 K) and pressure (5-60 Torr). CN radicals were generated by 193-nm excimer laser photolysis of dilute C{sub 2}N{sub 2}/Ar mixtures. Radical decays were monitored by laser-induced fluorescence from the B{sup 2}{Sigma}{sup +} {l arrow} X{sup 2}{Sigma}{sup +} transition near 387 nm under pseudo-first-order conditions. Arrhenius plots of the rate constants show significant curvature. The temperature-dependent rate constants have been fit to modified Arrhenius expressions of the form k = AT{sup n} exp({minus}E/T). This study represents the widest continuous temperature range over which rate constants for these reactions have been measured directly. The reaction kinetics and products of these reactions were also studied at 295 K by diode laser absorption. Rate constants obtained from product growth are in good agreement with the laser-induced fluorescence data. For these reactions at 295 K, HCN was found to be the dominant observable product.

• OSTI ID: 7130973
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:22; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
400500 -- Photochemistry
400800* -- Combustion
Pyrolysis
& High-Temperature Chemistry
ALKANES
ARRHENIUS EQUATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISTRY
CYANIDES
DATA
DECOMPOSITION
ELECTROMAGNETIC RADIATION
EMISSION SPECTROSCOPY
EQUATIONS
ETHANE
EXPERIMENTAL DATA
FLUORESCENCE SPECTROSCOPY
HYDROCARBONS
INFORMATION
KINETICS
LASER RADIATION
METHANE
NUMERICAL DATA
ORGANIC COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOCHEMISTRY
PHOTOLYSIS
PROPANE
RADIATIONS
RADICALS
REACTION KINETICS
SPECTROSCOPY
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K
ULTRAVIOLET RADIATION