104197-48-0Relevant articles and documents
Activation Parameters for the Additions of Arylhalocarbenes to Alkenes
Moss, Robert A.,Lawrynowicz, Witold,Turro, Nicholas J.,Gould, Ian R.,Cha, Yuan
, p. 7028 - 7032 (1986)
By use of nanosecond laser flash photolytic methods, absolute rate constants have been obtained for the additions of p-(trifluoromethyl)phenylbromocarbene (CF3C6H4CBr), phenylbromocarbene (PhCBr), phenylchlorocarbene (PhCCl), phenylfluorocarbene (PhCF), and p-methoxyphenylfluorocarbene (CH3OC6H4CF) to tetramethylethylene (TME) and 1-hexene.The rate constants ranged from 1.7 x 109 (CF3C6H4CBr/TME) to 5.0 x 104 L/(M.s) (CH3OC6H4CF)/1-hexene); classical structure/reactivity relations were obeyed.Determination of the rate constants at temperatures between 315 and 200 K gave Ea, logA, ΔH*, ΔS*, and ΔG* for the 10 reactions.All of thereactions were dominated by ΔS*, ΔG* ranged from 5.0 to 11 kcal/mol for the fastest and slowest reactions.Negative values of Ea were observed some of the faster reactions at higher temperatures.These results are analyzed in terms of single-step addition reactions where ΔG* is dominated by ΔS* and, alternatively, in terms of a two-steps machanism proceeding through a carbene-alkene complex.