Atoms, photo generation

Zhang X, Cornelis R, De Kimpe J, and Mees L (1996) Arsenic speciation in serum of uraemic patients based on liquid chromatography with hydride generation atomic absorption spectrometry and on-line UV photo-oxidation digestion. Anal Chim Acta 319 177-185. 

So, in summary, photo-initiated chlorination of methane requires UV light to generate hot atoms of molecular chlorine, which subsequently dissociate ... 

H-atom abstraction has been demonstrated to be the mechanism of action of excited uranyl ions, and in this case negligible base oxidation is found. Nucleo-base (especially guanine) oxidation is the principal reaction caused by singlet oxygen and this reactive species can be generated by a number of the complexes (e.g. many Ru(II)polypyridyls and porphyrins). It is worth pointing out, however, that the yield of may be lower when the sensitiser is bound to DNA, and it is the authors view that some of the reactions claimed to proceed via 62 may be caused by direct reaction of the photo-oxidised sensitiser with the DNA. 

V In gaseous mixtures of H2 and Cl2, Cl atoms generated by photo- f ociation initiate a chain reaction by abstraction of H from H2 ... 

Atallah, R.H. and D.A. Kalman. 1991.0n-line photo-oxidation for the determination of organoarsenic compounds by atomic-absorption spectrometry with continuous arsine generation. Talanta 38 167-173. 

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