Spectroscopic Studies of the Products of the Reactions of Electronically Excited Atoms and Small Molecules.
Final rept. 15 Apr 83-14 Apr 86,
PITTSBURGH UNIV PA DEPT OF CHEMISTRY
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The rate constants and products of the reactions of electronically excited Ar, Kr, and Xe atoms and N2A 3 Sigma sub u and COa 3Pi molecules with several oxygen, hydrogen and chlorine containing compounds have been determined, using emission spectroscopy, atomic resonance fluorescence and laser induced fluorescence measurements in discharge flow systems. As found previously for the excited noble gases, there is a strong correlation between the rate constants for quenching of N2A and the availability of accessible acceptor states of the quenching molecule, as revealed by its absorption spectrum. Consistent with this correlation, the rate constants for several inefficient quenchers are greatly enhanced reactions with vibrationally-excited N2A. Energy transfer leading to molecular dissociation is the dominant mechanism, when energetically allowed, for most reactions of N2A studied. Similar behavior is shown by both efficient and inefficient quenchers, and the results parallel the UV photochemistry of these molecules. In contrast to N2A, the isoenergetic COa 3 Pi species if quenched very efficiently by H2O, CH4 and H2. The reaction products have been investigated in an attempt to gain insight into this difference in behavior.
- Radiation and Nuclear Chemistry
- Atomic and Molecular Physics and Spectroscopy