Evidence for HOOO Radicals in the Formation of Alkyl Hydrotrioxides (ROOOH) and Hydrogen Trioxide (HOOOH) in the Ozonation of C−H Bonds in Hydrocarbons<sup>1</sup>
作者:Janez Cerkovnik、Evgen Eržen、Jože Koller、Božo Plesničar
DOI:10.1021/ja017320i
日期:2002.1.1
the first step of the ozonation of the C-H bonds in hydrocarbons, i.e., the formation of the caged radical pair (R(**)OOOH), which allows both (a) collapse of the radical pair to ROOOH and (b) the abstraction of the hydrogen atom from alkyl radical R(*) by HOOO(*) to form HOOOH. The B3LYP/6-311++G(d,p) (ZPE) calculations revealed that HOOO radicals are considerably stabilized by forming intermolecularly
异丙苯 (1a) 在丙酮、乙酸甲酯和叔丁基甲基醚中在 -70 摄氏度的低温臭氧化产生相应的三氧化二氢,C(6)H(5)C(CH(3))(2)OOOH (2a),连同三氧化氢,HOOOH。然而,三苯基甲烷 (1b) 的臭氧化仅产生三苯基甲基氢氧化铝 (C(6)H(5))(3)COOOH (2b)。这些观察结果与先前报道的实验证据一起,似乎支持烃中 CH 键臭氧化第一步的“自由基”机制,即形成笼状自由基对 (R(**)OOOH) ,这允许 (a) 自由基对塌陷为 ROOOH 和 (b) HOOO(*) 从烷基自由基 R(*) 中提取氢原子以形成 HOOOH。B3LYP/6-311++G(d, p) (ZPE) 计算表明,HOOO 自由基通过与丙酮 (BE = 8.55 kcal/mol) 和二甲醚 (7.04 kcal/mol) 形成分子间氢键复合物而显着稳定。与在非碱性溶剂中进行的臭氧化相比