Isolation of a Carborane-Fused Triazole Radical Anion

摘要

Radicals play important roles as reactive intermediates in biological systems, in materials science, and in the construction of conducting polymers, and as spin carriers for solar-cell applications. With the exception of simple inorganic molecules, such as NO and O2, most radicals are transient species that defy isolation. In 1900, Gomberg, in an attempt to isolate hexaphenylethane, discovered the first persistent organic radical species, triphenylmethylene. Following the pioneering studies of Gomberg, a variety of persistent and stable radical species of the second-row elements were reported. These species are often stabilized by kinetic protection of the radical center and/or by significant derealization of the unpaired electron. Further stability can also be bestowed by the incorporation of a heavier main-group element into the spin system.