Kinetic studies of the reaction of the hydroxymethyl radical with NO and NO sub 2

Journal Article · Thu Jun 29 00:00:00 EDT 1989 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100350a027· OSTI ID:7157129

Nesbitt, F L ^[1]; Payne, W A; Stief, L J ^[2]

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1. Catholic Univ. of America, Washington, DC (USA)
2. NASA, Goddard Space Flight Center, Greenbelt, MD (USA)

The absolute rate constant for the reaction CD{sub 2}OH + NO has been measured from 230 to 373 K in a discharge-flow system. The decay of the CD{sub 2}OH radical was monitored in excess NO by collision-free sampling mass spectrometry. At 298 K, k{sub 1} = (2.2 {plus minus} 0.4) {times} 10{sup {minus}12} cm{sup 3}s{sup {minus}1} (2{sigma}) independent of pressure from 0.5 to 1.5 Torr. For the 230-298 K interval, an activation energy of 1.2 kcal/mol is obtained, but k{sub 1} does not appear to change within experimental error on going from 298 to 373 K. The absolute rate constant at 298 K has also been measured for the reaction CH{sub 2}OH + NO{sub 2} by the same technique. The result is k{sub 2} = (8.3 {plus minus} 4.1) {times} 10{sup {minus}12} cm{sup 3} s{sup {minus}1} (2{sigma}). Qualitative detection was made of D{sub 2}CO and H{sub 2}CO as products of these reactions, but no evidence was obtained for the expected accompanying products HNO and HNO{sub 2} nor for the CD{sub 2}OHNO and CH{sub 2}OHNO{sub 2} adducts. It is suggested, partially by analogy with the CH{sub 2}OH + O{sub 2} reaction, that the reaction mechanism in both cases involves initial formation of a vibrationally excited complex that, depending on reaction conditions, can dissociate back to reactants or, after isomerization, dissociate to products. Collisional stabilization of the addition complex may be feasible, but they have no evidence for this under the low-pressure condition of their experiments. The rate constants for reaction of CH{sub 2}OH with O{sub 2}, NO, and NO{sub 2} are briefly compared.

• OSTI ID: 7157129
• Journal Information: Journal of Physical Chemistry; (USA), Vol. 93:13; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
54 ENVIRONMENTAL SCIENCES
HYDROXYL RADICALS
CHEMICAL REACTION KINETICS
METHYL RADICALS
ATMOSPHERIC CHEMISTRY
COMBUSTION PRODUCTS
DATA ANALYSIS
EXPERIMENTAL DATA
MEASURING INSTRUMENTS
MEASURING METHODS
NITROGEN OXIDES
ALKYL RADICALS
CHALCOGENIDES
CHEMISTRY
DATA
INFORMATION
KINETICS
NITROGEN COMPOUNDS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
RADICALS
REACTION KINETICS
400000* - Chemistry
400201 - Chemical & Physicochemical Properties
400202 - Isotope Effects
Isotope Exchange
& Isotope Separation
540110