Jump to main content
Jump to site search

Issue 1, 1998
Previous Article Next Article

Generation of tricyanomethyl spin adducts of α-phenyl-N-tert-butylnitrone (PBN) via non-conventional mechanisms

Abstract

Spin adducts, formally derived from tricyanomethyl radical attachment to α-phenyl-N-tert-butylnitrone (PBN; IUPAC name: N-benzylidene-tert-butylamine N-oxide), have been generated by various methods, such as oxidation of a mixture of tricyanomethanide ion and PBN by tris(4-bromophenyl)aminium ion or bromine, photo-oxidation of a mixture of tricyanomethane and PBN with 2,4,6-tris(4-methoxyphenyl)pyrylium ion as a sensitizer, or photolysis of chlorotricyanomethane and PBN at –30 °C, the low temperature being necessary to avoid fast concurrent cycloaddition with PBN. Both the C- and N-connected spin adducts, (NC)3C-PBN˙ and (NC)2C[double bond, length half m-dash]C[double bond, length half m-dash]N–PBN˙, have been characterized, as has an aminoxyl formed by elimination of hydrogen cyanide from the former species, (NC)2C[double bond, length half m-dash]C(Ph)N(O˙)But. For comparison, similar experiments have been performed using carbamoyldicyanomethanide ion and carbamoylchlorodicyanomethane and the spin adduct H2NCO(CN)2C-PBN˙ has been characterized.

The redox properties of tricyanomethanide ion, carbamoyldicyanomethanide ion, chlorotricyanomethane and carbamoylchlorodicyanomethane have been studied by cyclic voltammetry. For chlorotricyanomethane, the redox reactivity has also been evaluated by its propensity to generate radical cations from aromatic substrates ArH in 1,1,1,3,3,3-hexafluoropropan-2-ol. Tricyanomethanide ion has E [(CN)3C˙/(CN)3C]rev at 1.35 V (vs. Ag/AgCl) in acetonitrile while chlorotricyanomethane with Epc at about 0.6 V and a capability to oxidize compounds with redox potentials up to ca. 1.5 V to radical cations, emerges as belonging to the strongest neutral organic electron acceptors.

Back to tab navigation
Please wait while Download options loads

Article type: Paper
DOI: 10.1039/A704634K
Citation: J. Chem. Soc., Perkin Trans. 2, 1998, 49-58
  •   Request permissions

    Generation of tricyanomethyl spin adducts of α-phenyl-N-tert-butylnitrone (PBN) via non-conventional mechanisms

    L. Eberson and J. J. McCullough, J. Chem. Soc., Perkin Trans. 2, 1998, 49
    DOI: 10.1039/A704634K

Search articles by author