Formation of Inorganic Radicals and Their Dimeric Radical Anions

Formation of Inorganic Radicals and Their Dimeric Radical Anions 

Hydroxyl radicals react with many halide (pseudohalide) ions at close to diffusion-controlled rates thereby forming a three-electron-bonded adduct radical [e.g., reaction (1) k = 1.1 x 1010 dm3 mol-1 s 1 Zehavi and Rabani 1972], These adducts may decompose into OH and the halide (pseudohalide) radical which then complexes with another halide (pseudohalide) ion yielding the dihalogen radical anion [reactions (2) and (3) k2 = 4.2 x 106 s 1 k3 1010 dm3 mol 1 s 1 for resonance Raman spectra of such intermediates, see Tripathi et al. 1985]. 

They are held together via a weak oo three-electron bond. This mechanism 

A number of mixed complexes have also been characterized (Schoneshofer and Henglein 1969, 1970 Schoneshofer 1969, 1973 Ershov et al. 2002). In this context, it is interesting that Cl also undergoes a weak three-electron bond with water (Sevilla et al. 1997). 

Similar hypervalent iodine radicals (9-1-2) are formed in the reaction of alkyl radicals with alkyliodides (R + RI — R2I ), and as an intramolecular complex they are stable enough that a reaction with 02 is only low (Miranda et al. 2000). Such 9-X-2 radicals have also been postulated as intermediates in the reduction of alkylhalides by a-hydroxyalkyl radicals (Lemmes and von Sonntag 1982). 

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