在非质子溶剂中，超氧离子对卤代氟烃（氟利昂和卤仿）的氧化作用。

Oxygenation by superoxide ion of halogenofluorocarbons (Freons and haloforms) in aprotic solvents.

作者信息

Hojo M, Sawyer D T

机构信息

Department of Chemistry, Texas A&M University, College Station 77843.

出版信息

Chem Res Toxicol. 1989 May-Jun;2(3):193-6. doi: 10.1021/tx00009a012.

DOI:10.1021/tx00009a012

PMID:2562422

Abstract

The reactivity of chloro- and bromofluoromethanes (Freons and others) with superoxide ion (O2.-) has been evaluated by cyclic voltammetry in dimethylformamide (DMF). Substitution of fluorine atoms into chloromethanes results in a substantial decrease in their reactivity with O2.- (relative rates: CCl4 much greater than CF4, much greater than CCl4 much greater than FCCl3, CCl4 much greater than F2CCl2, CCl4 much greater than F3CCl, H3CCl much greater than F3CCl, and H2CCl2 much greater than F2CCl2). The bromo derivatives react much faster with O2.- than the corresponding chloro compounds (F3CBr much greater than F3CCl, F2CBr2 much greater than F2CCl2, and FCBr3 much greater than FCCl3). The rates of reaction for HCCl3, HCFCl2, and HCF2Cl are approximately the same, and the reactions appear to have a common path via dehydrochlorination. Reaction stoichiometries, apparent second-order rate constants, and product profiles have been determined for these fluoromethanes and related chlorofluoroethanes.

摘要

氯氟甲烷和溴氟甲烷（氟利昂及其他）与超氧离子（O₂⁻）的反应活性已通过在二甲基甲酰胺（DMF）中的循环伏安法进行了评估。将氟原子取代氯甲烷中的氯原子会导致它们与O₂⁻的反应活性大幅降低（相对反应速率：CCl₄远大于CF₄，远大于CCl₄远大于FCCl₃，CCl₄远大于F₂CCl₂，CCl₄远大于F₃CCl，H₃CCl远大于F₃CCl，H₂CCl₂远大于F₂CCl₂）。溴代衍生物与O₂⁻的反应比相应的氯代化合物快得多（F₃CBr远大于F₃CCl，F₂CBr₂远大于F₂CCl₂，FCBr₃远大于FCCl₃）。HCCl₃、HCFCl₂和HCF₂Cl的反应速率大致相同，并且这些反应似乎通过脱氯化氢有一条共同的反应路径。已确定了这些氟甲烷及相关氯氟乙烷的反应化学计量、表观二级速率常数和产物分布。