Kinetics Studies of Two Free Radicals, Amidogen Radical and Allyl Radical: Amidogen Radical(A2A1) Emission Lifetimes in the (0,9,0) and (0,8,0) Bands and Allyl Radical Reactions With Nitrogen Dioxide, Methyl Radical and Allyl Radical

Many interesting chemical reactions occurring in combustion, pyrolysis and oxidation of organic compounds in atmospheres involve a complex multitude of elementary gas phase reactions involving small molecules. Free radicals are among the critical intermediates in hydrocarbon reactions and in combustion systems. This talk describes two projects that study key species of interest to planetary atmospheres, comets and combustion systems. Allyl and amidogen radicals play important mechanistic roles in atmospheric, and combustion systems.;The chemistry of small unsaturated hydrocarbon radicals such as allyl are particularly important. Resonantly stabilized free radicals such as allyl are primary building blocks for growth species in the formation of polycyclic aromatic hydrocarbons and soot in combustion of hydrocarbon-based fuels. The pressure-dependent product channels in the allyl radical self-reaction, reaction with methyl radical and nitrogen dioxide have been studied. Quantitative gas chromatograph/mass spectrometry/flame ionization analysis of reaction products is used which enables us to accurately characterize the nature and yield of reaction products and determine branching ratios and overall reaction mechanism. Finally, radiative lifetimes of NH2 at low pressure where effects of collisions are neglected are discussed in light of their dependence on rotational state.