Campus Units

Chemistry, Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

7-30-2012

Journal or Book Title

Journal of the American Chemical Society

Volume

134

Issue

31

First Page

13018

Last Page

13026

DOI

10.1021/ja303440n

Abstract

Metal alkylperoxides are remarkable, highly effective, yet often thermally unstable, oxidants that may react through a number of possible pathways including O–O homolytic cleavage, M–O homolytic cleavage, nucleophilic O-atom transfer, and electrophilic O-atom transfer. Here we describe a series of zinc alkyl compounds of the type ToMZnR (ToM = tris(4,4-dimethyl-2-oxazolinyl)phenylborate; R = Et, n-C3H7, i-C3H7, t-Bu) that react with O2 at 25 °C to form isolable monomeric alkylperoxides ToMZnOOR in quantitative yield. The series of zinc alkylperoxides is crystallographically characterized, and the structures show systematic variations in the Zn–O–O angle and O–O distances. The observed rate law for the reaction of ToMZnEt (2) and O2 is consistent with a radical chain mechanism, where the rate-limiting SH2 step involves the interaction of •OOR and ToMZnR. In contrast, ToMZnH and ToMZnMe are unchanged even to 120 °C under 100 psi of O2 and in the presence of active radical chains (e.g., •OOEt). This class of zinc alkylperoxides is unusually thermally robust, in that the compounds are unchanged after heating at 120 °C in solution for several days. Yet, these compounds are reactive as oxidants with phosphines. Additionally, an unusual alkylperoxy group transfer to organosilanes affords ToMZnH and ROOSiR3′.

Comments

Reprinted (adapted) with permission from Journal of the American Chemical Society 134 (2012): 13018, doi: 10.1021/ja303440n. Copyright 2012 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

Included in

Chemistry Commons

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