Free Radical Reactivity of a Phosphaalkene Explored Through Studies of Radical Isotopologues

Peer reviewed: 
Yes, item is peer reviewed.
Scholarly level: 
Final version published as: 

Published on line 18 November 2018 in Angewandte Chemie International Edition

DOI: 10.1002/anie.201810967

Date created: 
isotope effects
muon spin spectroscopy

Muonium (Mu), an H atom analogue, is employed to probe the addition of free radicals to the P=C bond of a phosphaalkene. Specifically, two unprecedented muoniated free radicals, MesP•-CMu(Me)2 (1a, minor product) and MesPMu-C•Me2 (1b, major product), were detected by muon spin spectroscopy (µSR) when a solution of MesP=CMe2 (1: Mes = 2,4,6-trimethylphenyl) was exposed to a beam of positive muons (µ+). The µ+ serves as a source of Mu (i.e. Mu = µ+ + e–). To confirm the identity of the major product 1b, its spectral features were compared to its isotopologue, MesPH-C•(Me)CH2Mu (2a). Conveniently, 2a is the sole product of the reaction of MesPH(CMe=CH2) (2) with Mu. For all observed radicals, muon, proton and phosphorus hyperfine coupling constants were determined by µSR and compared to DFT-calculated values.

Document type: 
You are free to copy, distribute and transmit this work under the following conditions: You must give attribution to the work (but not in any way that suggests that the author endorses you or your use of the work); You may not use this work for commercial purposes; You may not alter, transform, or build upon this work. Any further uses require the permission of the rights holder (or author if no rights holder is listed). These rights are based on the Creative Commons Attribution-NonCommercial-NoDerivatives License.