Kinetics and mechanism of the reaction of hydroxyl radicals with acetonitrile under atmospheric conditions

Journal Article · Thu Feb 07 04:00:00 EST 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100156a037· OSTI ID:5231028

Hynes, A J; Wine, P H ^[1]

---

1. Georgia Inst. of Tech., Atlanta (USA)

The pulsed laser photolysis-pulsed laser induced fluorescence technique has been employed to determine absolute rate coefficients for the reaction OH + CH{sub 3}CN (1) and its isotopic variants, OH + CD{sub 3}CN (2), OD + CH{sub 3}CN (3), and OD + CD{sub 3}CN (4). Reactions 1 and 2 were studied as a function of pressure and temperature in N{sub 2}, N{sub 2}/O{sub 2}, and He buffer gases. In the absence of O{sub 2} all four reactions displayed well-behaved kinetics with exponential OH decays and pseudo-firt-order rate constants which were proportional to substrate concentration. Data obtained in N{sub 2} over the range 50-700 Torr at 298 K are consistent with k{sub 1} showing a small pressure dependence. The Arrhenius expression obtained by averaging data at all pressures is k{sub 1}(T) = (1.1{sub {minus}0.3}{sup +0.5}) {times} 10{sup {minus}12} exp(({minus}1,130 {plus minus} 90)/T) cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}. The kinetics of reaction 2 are found to be pressure dependent with k{sub 2} (298 K) increasing from (1.21 {plus minus} 0.12) {times} 10{sup {minus}14} to (2.16 {plus minus} 0.11) {times} 10{sup {minus}14} cm{sup 3} molecule{sup {minus}1}s{sup {minus}1} over the pressure range 50-700 Torr of N{sub 2} at 298 K. Data at pressures >600 Torr give k{sub 2}(T) = (9.4{sub {minus}5.0}{sup +13.4}) {times} 10{sup {minus}13} exp(({minus}1,180 {plus minus} 250)/T) cm{sup 3} molecule{sup {minus}1}s{sup {minus}1}.

• OSTI ID: 5231028
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:3; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500 -- Photochemistry
54 ENVIRONMENTAL SCIENCES
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
ACETONITRILE
ARRHENIUS EQUATION
ATMOSPHERIC CHEMISTRY
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISTRY
DATA
DECOMPOSITION
EQUATIONS
EXPERIMENTAL DATA
FLUORESCENCE
HYDROXYL RADICALS
INFORMATION
KINETICS
LASERS
LUMINESCENCE
NITRILES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PRESSURE DEPENDENCE
RADICALS
REACTION KINETICS
TEMPERATURE DEPENDENCE