Trityl-based alkoxyamines as NMP controllers and spin-labels

Gérard Audran (1) , Elena Bagryanskaya, (2) , Paul Brémond (1) , Mariya Edeleva (2) , Marque S.R.A. (1) , Dimitri Parkhomenko (2) , Olga Rogozhnikova, (2) , Victor Tormyshev (2) , Evgeny V. Tretyakov (2) , Dimitry Trukhin, (2) , Shivetyeva I Zhivetyeva, (2)

1 ICR - Institut de Chimie Radicalaire
2 RAS, SB, NN - Vorozhtsov Novosibirsk Institute of Organic Chemistry

Recently, new applications of trityl-nitroxide biradicals were proposed. In the present study, attachment of a trityl radical to alkoxyamines was performed for the first time. The rate constants k(d) of C-ON bond homolysis in these alkoxyamines were measured and found to be similar to those for alkoxyamines without a trityl moiety. The electron paramagnetic resonance (EPR) spectra of the products of alkoxyamine homolysis (trityl-TEMPO and trityl-SG1 biradicals) were recorded, and the corresponding exchange interactions were estimated. The decomposition of trityl-alkoxyamines showed more than an 80% yield of biradicals, meaning that the C-ON bond homolysis is the main reaction. The suitability of these labelled initiators/controllers for polymerisation was exemplified by means of a successful nitroxide-mediated polymerisation (NMP) of styrene. Thus, this is the first report of a spin-labelled alkoxyamine suitable for NMP.

Keywords: ON BOND HOMOLYSIS; NITROXIDE-MEDIATED POLYMERIZATION; DYNAMIC NUCLEAR-POLARIZATION; RADICAL POLYMERIZATION; LABILE ALKOXYAMINES; RATE-CONSTANT; EPR; FRAGMENT; OXYGEN; SENSITIVITY

Domains: Chemical Sciences; Organic chemistry; Chemical Sciences; Polymers

Gérard Audran, Elena Bagryanskaya,, Paul Brémond, Mariya Edeleva, Marque S.R.A., et al.. Trityl-based alkoxyamines as NMP controllers and spin-labels. Polymer Chemistry, 2016, 7 (42), pp.6490-6499. ⟨10.1039/c6py01303a⟩. ⟨hal-01408195⟩