Phenoxy radicals coefficients

The chemistry of phenoxy (CeHsO ) radical has been of interest for several decades. Benson et al. proposed the first rate coefficient for its unimolecular decomposition, while Lin and Lin provided information on the Arrhenius parameters for the reaction. Experimental and theoretical studies have examined phenoxy radical s elec-... 

The photolysis of phenyl benzoate 8.88 is an example of the photo-Fries rearrangement, in which the acyl radical is created close to a phenoxy radical 8.89. The C—O bond is weakened by the presence of an electron in the n orbital of the ester conjugated system. The radical coupling then shows the usual selectivity for C—C bond formation, with the para selectivity in line with the coefficients of the SOMO of the phenoxy radical (see page 291). 

Reactions with OH, NO3, and Cl with benzaldehyde all occur by abstraction of the aldehydic H to form the benzoyl radical. The following mechanism (figure IV-F-1) and rate coefficient data are taken from the Master Chemical Mechanism (MCMvS.l http //mcm.leeds.ac.uk/MCM/). Addition of O2 to benzoyl leads to formation of the benzoyl peroxy radical. Subsequent reaction with NO, followed by O2 and then decarboxylation, gives the phenyl peroxy radical which reacts with NO to form phenoxy. The main reactions of phenoxy are with O3 to regenerate phenyl peroxy and with NO2 to form nitrophenol the rate coefficents for these two reactions are 3 x 10 and 2 x 10 cm molecule" s respectively. 

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