烯烃加成反应活性与烷基极化效应的关系

Correlation between the Addition Reactivity and Alkyl Polarizability Effect for Alkenes

烯烃的自由基加成和亲电加成速率受不同的因素控制 .对于仅仅含烷基取代的简单烯烃 :( 1)与OH自由基加成速率 -logkOH可由π键上烷基极化效应指数的几何平均值GMPEIπ关联 :-logkOH=a +bGMPEIπ +c(GMPEIπ) 2 ;( 2 )与亲电试剂加成速率logk可由π键两端碳原子所连基团极化效应指数PEI(L)和PEI(S)关联 :logk =a +bPEI(L) +cPEI(S) ,其中的PEI(L)和PEI(S)

The rate constants of radical and electrophilic addition to alkenes are dominated by different factors. For the simple alkenes with only alkyl groups: (1) its rate constants -log k OH for the addition of OH radical can be correlated with the geometric mean polarizability effect index of π bond (GMPEIπ): -log k OH=a+bGMPEIπ+c(GMPEIπ) 2, and (2) its rate constants (log k) for the addition of electrophilic reagents can be correlated with the two parameters PEI(L) and PEI(S): log k=a+bPEI(L)+cPEI(S), where PEI(L) and PEI(S) represent the larger and smaller polarizability effect of alkyl groups connecting with two carbon atoms on the double bond of alkenes, respectively.