α,β-HOQOOH自由基β-断键反应类动力学研究  

Kinetic study of theβ-scission reactions forα,β-hydroxyl-hydroperoxyalkyl radicals(α,β-HOQOOH)

作　　者：康楠 李娟琴[1] 陈斯渝 朱权[1] 李泽荣[2] KANG Nan;LI Juan-qin;CHEN Si-yu;ZHU Quan;LI Ze-rong(College of Chemical Engineering,Sichuan University,Chengdu 610065,China;College of Chemistry,Sichuan University,Chengdu 610064,China)

机构地区：[1]四川大学化学工程学院,四川成都610065 [2]四川大学化学学院,四川成都610064

出　　处：《化学研究与应用》2023年第10期2459-2469,共11页Chemical Research and Application

摘　　要：α,β-羟基氢过氧烷基(α,β-HOQOOH)自由基的β-断键反应类在醇和烯烃的低温燃烧中至关重要,该反应类中生成的相对不活泼的HO_(2)自由基是导致负温度系数行为的原因之一,它对醇和烯烃的低温氧化具有抑制作用。因此本文以该反应类为研究对象,并根据自由基所在碳原子类型和过渡态反应中心上是否连有羟基将该反应类划分为不同子类。在本文工作中,使用M06-2X/6-311+G(d,p)方法进行几何结构优化和单点能计算;使用传统过渡态理论计算高压极限速率常数,并根据简单速率规则法构建了相应的高压极限速率规则。本文通过理论计算为该反应类提供了更准确的高压极限速率常数并建立相应的高压极限速率规则,这有利于更可靠的醇和烯烃燃烧详细机理模型的构建。Theβ-scission reaction class forα,β-hydroxyl-hydroperoxyalkyl(α,β-HOQOOH)radicals plays a crucial role in the low temperature combustion of alcohols and alkenes.The generation of the relatively unreactive HO_(2)radical in this reaction is one of the factors leading to the negative temperature coefficient behavior,which hinders the low temperature oxidation of alcohols and alkenes.In this study,we investigate this reaction class by dividing it into subclasses based on the nature of carbon atom where the radical is located and the hydroxyl group's position either within or outside the transition state's reaction center.We use the M06-2X/6-311+G(d,p)method for geometry optimization and single point electronic energy calculation.The TST theory is employed to calculate the high pressure limit rate constants,and these are then used to construct the high pressure limit rate rules by averaging the rate con-stants of representative reactions in each subclass.Our work provides accurate rate constants and rate rules for this reaction class,which can aid in constructing more accurate combustion mechanism models for alcohols and alkenes.

关 键 词：α β-羟基氢过氧烷基自由基 β-断键反应类 动力学参数 反应类规则 

分 类 号：O643.1[理学—物理化学]