title: Macromolecular polyradicals with cyclic triphosphazene as a core. Spectral and electrochemical properties.
abstract: Stable cyclotriphosphazenes 5 and 6, with three and four carbon radical centers, have been prepared by condensation of (4-hydroxy-2,6-dichlorophenyl)bis(2,4,6-trichlorophenyl)methyl radical (4) with tetrachloro-2,2'-dioxybiphenylcyclotriphosphazene (7). EPR studies of both polyradicals in fluid solution suggest an electronic communication through the PN multiple bonds of the cycle. EPR spectral results in frozen solutions and magnetic susceptibility measurements in the solid are consistent with very weak electron-electron dipolar interactions. Reductive cyclic voltammetry shows a single three-electron redox couple for triradical 5 and a single four-electron redox couple for tetraradical 6. Both polyradicals 5 and 6 have been chemically oxidized to a stable trication 5(3+) and a tetracation 6(4+), respectively, by electron-transfer reactions.
authors.affiliation: Departamento de Química Orgánica e Inorgánica, Universidad de Oviedo, Oviedo 33071, Spain.
authors.forename: Gabino A
authors.initials: GA
authors.lastname: Carriedo
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: García Alonso
authors.forename: P
authors.initials: P
authors.lastname: Gómez Elipe
authors.forename: Enric
authors.initials: E
authors.lastname: Brillas
authors.forename: Amilcar
authors.initials: A
authors.lastname: Labarta
authors.forename: Luis
authors.initials: L
authors.lastname: Juliá