Dimethylselenide as a probe for reactions of halogenated alkoxyl radicals in aqueous solution. Degradation of dichloro- and dibromomethane.

Using pulse radiolysis and steady-state gamma-radiolysis techniques, it has been established that, in air-saturated aqueous solutions, peroxyl radicals CH 2HalOO (*) (Hal = halogen) derived from CH 2Cl 2 and CH 2Br 2 react with dimethyl selenide (Me 2Se), with k on the order of 7 x 10 (7) M (-1) s (-1), to form HCO 2H, CH 2O, CO 2, and CO as final products. An overall two-electron oxidation process leads directly to dimethyl selenoxide (Me 2SeO), along with oxyl radical CH 2HalO (*). The latter subsequently oxidizes another Me 2Se molecule by a much faster one-electron transfer mechanism, leading to the formation of equal yields of CH 2O and the dimer radical cation (Me 2Se) 2 (*+).

The formation of a cyclic diacetal of methyl alpha-D-mannopyranoside with a 16-membered macrocyclic loop.

The X-ray structure of a diacetal with a 16-membered macrocyclic loop, which was obtained as a product of the condensation of methyl alpha-D-mannopyranoside and 1,4-bis(2-formylphenoxy)butane is presented together with polymeric compounds resulting from polycondensation; a similar polymer was formed in the reaction of methyl 2,3:4,6-di-O-salicylidene-alpha-D-mannopyranoside with 1,4-dibromobutane.