Photochemistry of halogenated benzene derivatives. Part 2. Photoreactions of α-substituted p-chlorotoluenes

Photochemistry of halogenated benzene derivatives: Part VII. Photoincorporations of polychlorobenzenes with humic model monomers in aqueous acetonitrile solutions

“…Samples were not deaerated prior to photolysis. It should be noted that Pyrex transmits less than 1% of radiations below 290 nm [19].…”

“…For photolyses of PCBzs 1 to 6 in solutions containing humic model monomers 7 to 12, the extent of disappearance of the initial PCBz was determined using column A (5% Carbowax 20 M); column C (3% silicone OV 101) was used for the quantitation of the photoincorporated products listed in Tables 1 and 2. The products (Tables 1 and 2) were quantified by previously described techniques [2,9,10,18,19] that used the amount of undecomposed initial PCBz present in a photolyzate. The chemical yields of these photoproducts were calculated from the amount of…”

Photochemistry of halogenated benzene derivatives. Part VIII. Photoformation of 2-methyl-4,5,6,7-tetrachlorobenzoxazole from pentachlorophenol in water–acetonitrile

“…The solution-phase photoreactions of pentachlorophenol in wateracetonitrile (2:3 v/v) were carried out using previously reported (22)(23)(24)(25) Rayonet Photochemical Reactor (The Southern New England Ultra Violet Company) equipped with 16 RPR-3000 A lamps having an energy output of 90% in the wavelength range 290 to 3 10 nm. In order to determine the optimum UV light photolytic exposure time as well as the retention time of the desired photoproduct C8H4CI3NO (2) from 1 , analytical scale photolysis experiments were conducted in Pyrex glass tubes containing 2 mL sample solution each.…”

Selective Photosubstitution Reactions of Tertiary 1-Alkyl-1,1-diarylmethyl Chloride: Simultaneous Formation of Radicals and Carbocations from the Excited State of 1-Alkyl-1,1-diarylmethyl Chloride

“…Since then, it has been reported that photochemical reactions of a variety of substituted benzyl halides gave solvolysis products and homolysis products. [2][3][4][5] For benzhydryl chloride, steady state and laser flash photolyses have been studied; 6 photochemical reaction of benzhydryl chloride in acetonitrile (AN) containing n-octane gave six products; transient species such as benzhydryl radicals and cations, and excited benzhydryl radical have been identified. Several mechanisms for these reactions have been proposed: [2][3][4][5]7 Generally, benzyl type carbocations and radicals generated from the reactions proceed solvolysis and radical/radical coupling, respectively.…”

“…[2][3][4][5] For benzhydryl chloride, steady state and laser flash photolyses have been studied; 6 photochemical reaction of benzhydryl chloride in acetonitrile (AN) containing n-octane gave six products; transient species such as benzhydryl radicals and cations, and excited benzhydryl radical have been identified. Several mechanisms for these reactions have been proposed: [2][3][4][5]7 Generally, benzyl type carbocations and radicals generated from the reactions proceed solvolysis and radical/radical coupling, respectively. We wish to report that upon change of medium conditions the selective photoreactions of tertiary arylmethyl chloride are accomplished: in polar solvent solvolysis reactions principally undergo, whereas in nonpolar solvent reduction reactions occur.…”