Exchange Photochemical

Craig and Davidson have investigated the photochemical exchange, using light of wavelengths 365 m/r (a wavelength where the interaction complex absorbs... 

Borazine + D - Nadler and Porter reported on the photochemical exchange reaction of borazine with D2 at 184.9 nm. Products observed include B-mono-, B-di,... 

F . 9. Data ftom a mass spectrometric study of the photochemical exchange reaction of (-BHNH-)3 with D2. Initial conditions are indicated... 

The Barton reaction [102], A photochemical exchange process between a nitrite group and a proximate nonactivated hydrogen has been called the Barton reaction. The process appears to be limited to aliphatic compounds (Eq. 52). 

A quinone methide makes a surprising appearance as an intermediate of the photochemical exchange of deuterium from D20 into the 2 -position of 2-phenylphenol (13).27 29 No photochemical deuterium exchange is observed for reactions of the related phenylanisole 10 or phenylphenols 11 and 12, and deuterium exchange at the 4 -phenyl position of 13 is very much slower than... 

OCl 2 has been prepared by the photochemical combination of CO with an excess of Cl 2 [999] the excess dichlorine was removed by passage of the gases over antimony. The enrichment of in the photochemical exchange of CO with COCl j was predicted, on the basis of the partition function ratios, 293.16 K, to be about 11.4% [1%2]. This... 

The latter reaction and other thermal processes that lead to exchange are accelerated even by diffuse room light, and both thermal and photochemical exchange are inhibited by the oxidants Fe(CN) p, IrCl and Clj. A chain mechanism involving a catalytic intermediate, such as [PtCljj, may be responsible ... 

Oxygen consists of three stable isotopes 0, " O and " O. For most applications only the ratio between the more abundant Lso-topes, 0 and O, is measured. If all fractionation processes in the environmental system were purely mass-dependent, measurements of 0/ 0, would be redundant, as they could be predicted from the 0/ 0 ratio. However, it has recently been ob.served that photochemical exchange between O2, Oi, and CO, in the stratosphere involves mass-independent fractionation among the oxygen isotopes (1990 Thiemens et al., 1993a, b Thiemens, 1999). Thereby O2 becomes anomalously depleted, while CO2 becomes anomalously enriched. Because of this, measurements of 0/ 0 in atmospheric O2 and/or CO2 provide an independent piece of information. Conveniently, one may define an O anomaly tracer (A 0) (Thiemens et n/., 1995b)... 

Koch and A.H. Jones, A photochemical exchange reaction of Michler s ketone, J. Am. Chem. Soc. 92, 7503 (1970) D.I. Schuster and M.D. Goldstein, Photochemistry of ketones in sol ution. XXXVII. Plash photolysis of Michler s ketone in solution. Rate constants for decay and triplet excimer formation, J. Am. Chem. Soc. 95, 986 (1973) V.D. McGinnis and D.M. Dusek, Photopolymerization of methyl methacrylate with the use of 4,4 BIS (diethylamion) benzophenone as the photoinitiator, ACS Polym. Prepr. 15(1), 480 (1974). 

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