Vibrational relaxation of HOD by collisions with Ar atoms.

Vibrational relaxation of HOD(v12, v3) molecules by collisions with Ar was studied at 298 K (v12 denotes coupled bending, v2, and OD stretching, v1, vibrational modes and v3 denotes OH stretching mode). The vibrationally excited HOD molecules were generated by exothermic abstraction reactions of OD radicals with 13 different RH reactants and observed by infrared emission from a fast-flow reactor as a function of Ar pressure and reaction time. State-specific relaxation rate constants were obtained by comparison of the time evolution of the experimental vibrational distributions with numerical kinetic calculations for vibrational populations.

Vibrational relaxation of high levels of HO by collisions with Ar as studied by infrared chemiluminescence.

Vibrational relaxation of HO(v,v) molecules by collisions with Ar was studied at 298 K (v denotes the bending vibrational mode and v denotes the sum of the symmetric, v, and asymmetric, v, vibrational modes). The HO molecules from 14 different exothermic reactions of H-atom abstraction by OH radicals were observed by infrared emission from a fast flow reactor as a function of Ar pressure and reaction time. Numerical kinetic calculations were used to obtain rate constants for stretch-to-bend energy conversion, (v,v) → (v + 2,v - 1), and pure bend relaxation, (v,v) → (v - 1,v).

Infrared Chemiluminescence Study of the Reaction of Hydroxyl Radical with Formamide and the Secondary Unimolecular Reaction of Chemically Activated Carbamic Acid.

Reactions of OH and OD radicals with NHCHO and NDCHO were studied by Fourier transform infrared emission spectroscopy of the product molecules from a fast-flow reactor at 298 K. Vibrational distributions of the HOD and HO molecules from the primary reactions with the C-H bond were obtained by computer simulation of the emission spectra. The vibrational distributions resemble those for other direct H atom abstraction reactions, such as with acetaldehyde.

Branching Ratios and Vibrational Distributions in Water-Forming Reactions of OH and OD Radicals with Methylamines.

Reactions of OH and OD radicals with (CH3)3N, (CH3)2NH, and CH3NH2 were studied by Fourier transform infrared emission spectroscopy (FTIR) of the water product molecules from a fast-flow reactor at 298 K. The rate constants (4.4 ± 0.

Pressure dependence of butyl nitrate formation in the reaction of butylperoxy radicals with nitrogen oxide.

The yield of 1- and 2-butyl nitrates in the gas-phase reactions of NO with n-C4H9O2 and sec-C4H9O2, obtained from the reaction of F atoms with n-butane in the presence of O2, was determined over the pressure range of 100-600 Torr at 298 K using a high-pressure turbulent flow reactor coupled with a chemical ionization quadrupole mass spectrometer. The yield of butyl nitrates was found to increase linearly with pressure from about 3% at 100 Torr to about 8% at 600 Torr. The results obtained are compared with the available data concerning nitrate formation from NO reaction with other small alkylperoxy radicals.