Bach Robert D, Schlegel H Bernhard
Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States.
Department of Chemistry, Wayne State University, Detroit, Michigan 48202-3489, United States.
J Phys Chem A. 2020 Jun 11;124(23):4742-4751. doi: 10.1021/acs.jpca.0c02859. Epub 2020 May 27.
When dealing with organic peroxides in both laboratory and industrial applications, the relative strengths of the O-O bond are of vital importance, both from a safety and mechanistic perspective. Although it is well known that such oxidizing agents are highly reactive, reliable O-O bond dissociation energies (BDEs) have only recently been established. In an earlier report, we suggested a median O-O BDE value of ca. 45 kcal/mol for a variety of well-known peroxides based upon G2 ab initio calculations. In the present report, we have calculated the O-O BDE of twenty peroxides of varying structures at a more accurate CBS-APNO level. We have also compared these bond energies to the corresponding BDEs calculated with several DFT functionals and shown that the M06-2X functional produces O-O bond energies that compare very favorably with G4 and CBS-APNO values.
在实验室和工业应用中处理有机过氧化物时，从安全和机理角度来看，O - O键的相对强度至关重要。尽管众所周知这类氧化剂具有高反应活性，但可靠的O - O键解离能（BDEs）直到最近才得以确定。在早期的一份报告中，我们基于G2从头算计算，提出了各种知名过氧化物的O - O BDE中值约为45千卡/摩尔。在本报告中，我们在更精确的CBS - APNO水平上计算了20种结构各异的过氧化物的O - O BDE。我们还将这些键能与用几种密度泛函理论（DFT）泛函计算得到的相应BDE进行了比较，结果表明M06 - 2X泛函产生的O - O键能与G4和CBS - APNO值相比非常有利。
