Synthesis, electrochemical behavior and magnetic properties of polyradicals of the TTM series

Abstract

Condensation reactions between (4-amino-2,6-dichlorophenyl)bis(2,4,6-trichlorophenyl)methyl radical and a new hexafunctionalized radical of the TTM series, tris(3,5-dichloroformil-2,4,6-trichlorophenyl)methyl radical or its corresponding diamagnetic precursor 6 yield macromolecular heptaradical 3 and hexaradical 4, respectively, with high magnetic purity. Both solid polyradicals show stability in nitrogen at temperatures up to 300 °C and in solution their electronic absorptivities do not decrease appreciably for weeks. EPR studies of both polyradicals in solution suggest that unpaired electrons are exchange coupled, and at low temperatures they show weak dipolar spin–spin couplings. Their electrochemical behavior was analyzed by cyclic voltammetry and differential pulse voltammetry. Heptaradical 3 is reduced in seven-electron two-stage processes, and oxidized in seven-electron one-stage process.