Absolute chlorine atom quantum yield measurements in the UV and VUV gas-phase laser photolysis of CCl4

Kinetics and thermochemistry of the addition of atomic chlorine to acetylene

“…Details of the apparatus and technique have been given elsewhere [19,20]. Experimental parameters such as [CCl 4 ] and the photolysis energy F, together with the beam cross section of approximately 7 x 8 mm 2 and the absorption cross-section of CCl 4 [21], were employed to estimate the initial atomic concentration [Cl] 0 . Low intensities were employed to isolate the primary reaction from secondary processes involving the products of reaction or CCl 4 or C 2 H 2 photolysis.…”

Studies of the Kinetics and Thermochemistry of the Forward and Reverse Reaction Cl + C6H6 = HCl + C6H5

“…The initial Cl concentration, [Cl] 0 , was estimated using the measured laser output energy F, the beam cross section, and the CCl 4 absorption cross section which is (8.6 ( 0.5) × 10 -19 cm 2 (base e) at room temperature. 19 We neglected any variation of this cross section with temperature and used a quantum yield for Cl formation of 1.5. 19 This calculation does not account for the strong absorption of 193-nm radiation by benzene and therefore yields an upper limit to [Cl] 20 at higher temperatures CCl 4 is unsatisfactory, and accordingly at 922 K we employed their suggestion of NaCl(g) as the photolytic precursor for Cl.…”

“…19 We neglected any variation of this cross section with temperature and used a quantum yield for Cl formation of 1.5. 19 This calculation does not account for the strong absorption of 193-nm radiation by benzene and therefore yields an upper limit to [Cl] 20 at higher temperatures CCl 4 is unsatisfactory, and accordingly at 922 K we employed their suggestion of NaCl(g) as the photolytic precursor for Cl. NaCl evaporated from a porcelain boat in the gas entry sidearm.…”

Up-scaling aerosol functionalization. Photo-oxychlorination using vacuum ultraviolet radiation (VUV)

“…Electronic excitation leads to the homolysis of the C-Cl-bond (reaction (20)) with a quantum yield of approx. 1 24 , hence, efficiently generating Cl . for the initiation of the oxidative functionalization.…”

“…(reaction (9)) would provoke a diminution of [O 2 ] in the irradiated space along the flux of the aerosol and consequently favor the production of chlorinated compounds. Subtraction of the respective background signals from of the different signals I app,i and normalization of the corrected I' app,i for the respective absorption cross sections of photoionization σ i yield I corr,i (equation (23)) from which the content of the species to be analyzed (x i ) is calculated by using equation (24). Table 1 shows the values of σ i used and the contents of (i = Cl) for the two different radiant energies (Q e ) chosen.…”