Accession Number : ADA189432

Title :   Measurement of Rate Constants of Elementary Gas Reactions of Importance to Upper Atmosphere and Combustion Systems.

Descriptive Note : Final rept. 1 Mar 85-31 Aug 87,

Corporate Author : PITTSBURGH UNIV PA DEPT OF CHEMISTRY

Personal Author(s) : Golde, Michael F

PDF Url : ADA189432

Report Date : 31 Oct 1987

Pagination or Media Count : 22

Abstract : Important elementary gas phase reactions have been studied by the discharge flow technique, utilizing laser induced fluorescence to detect radical species and mass spectrometry to monitor stable reaction products. Both rate constants and reaction products have been determined. The H-abstraction reactions of F atoms and of OH radicals with CH3OH favor different reaction channels: the former yields predominantly methoxy radicals (CH30), whereas the latter strongly favors hydroxymethyl (CH2OH). The reaction of OH with CH30H shows a large kinetic isotope effect for this channel. The kinetics of CH30 with NO resemble those of CH30 with NO2 studied previously in this lab, namely a weak positive pressure dependence and a strong inverse temperature dependence and a strong inverse temperature dependence of the second order rate coefficient. Analysis of the rate data together with direct detection of reaction products have established that atom transfer to yield HNO + CH20 is the major channel at low pressures. A brief study of the reaction of NH2 with NO has shown that OH production is a minor channel, with a branching fraction of or = 0.04. Keywords: Chemical kinetics; Elementary reactions; Methoxy radicals; Laser induced fluorescence.

Descriptors :   *CHEMICAL RADICALS, *COMBUSTION, *REACTION KINETICS, *GLOW DISCHARGES, ATOMS, CHANNELS, COEFFICIENTS, CONSTANTS, DETECTION, FLOW, GASES, INVERSION, ISOTOPE EFFECT, LASER INDUCED FLUORESCENCE, LOW PRESSURE, MASS SPECTROMETRY, METHANE, OXYGEN, PRESSURE, PRODUCTION, RATES, REACTANTS(CHEMISTRY), STABILITY, TEMPERATURE, TRANSFER, UPPER ATMOSPHERE, VAPOR PHASES, NITROGEN OXIDES, HYDROXYL RADICALS, ATMOSPHERIC PHYSICS

Subject Categories : Physical Chemistry
      Atmospheric Physics
      Combustion and Ignition

Distribution Statement : APPROVED FOR PUBLIC RELEASE