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Emission and product quantum yield measurements reported here provide a new insight into the mechanism .of carbon dioxide formation in SO?-CO mixtures irradiated within the first singlet absorption band (2400-3200 A). The quantum yields of sulfur dioxide triplet-sensitized phosphorescence in biacetyl were determined in SOz-CO-biacetyl mixtures. The kinetic treatment of the data gives the fraction of the excited sulfur dioxide singlet molecules (IS02) which generate the emitting triplet ( 3S02) on undergoing quenching collisions with CO:(4) H. D. Mettee,

The gas phase photolysis of CP3CC13 in the presence of scveral alkanes has been used to obtain Arrhenius parameters for the abstraction of hydrogen atoms by the CF3CC12 radical :CFBCCI~ + RH -+ CF3CC12H + R Activation energies of 9.6 and 8.0 kcal/mole are found for abstraction from secondary and tertiary C-H bonds, respectively. The Arrhenius parameters are compared to those for CC13 and CFI radicals.

The B 1Σ+ state of carbon monoxide was created by a two-photon absorption of 230 nm laser radiation. The B 1Σ+ state was identified by the positions of the Q branch 0–0 absorption band and the vibrational bands of B 1Σ+ → A 1Π fluorescence occurring after excitation. Collision-induced b 3Σ+ → a 3Π emission in the 350 nm region was also observed. The lifetimes of the B 1Σ+ → A 1Π and the b 3Σ+ → a 3Π emission were obtained as well as the self-quenching rate constants and the CO (B 1Σ)) quenching rate by N2. In addition to the two-photon laser induced fluorescence of B 1Σ+ carbon monoxide, a three-photon resonant (2+1) ionization was observed. Laser power dependence studies indicate that ionization of the B 1Σ+ state was nearly saturated at the laser fluence used, implying that most CO (B 1Σ+) was ionized rather than fluorescing. The measured polarization ratios for circularly to linearly polarized excitation of fluorescence and ionization was much larger than the expected values suggesting that other three-photon processes are occurring and occur more efficiently for linear polarization.

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