One-Electron Reduction of Kinetically Stabilized Dipnictenes: Synthesis of Dipnictene Anion Radicals

The redox behavior of kinetically stabilized dipnictenes, BbtEEBbt [E = P, Sb, Bi; Bbt = 2,6-bis[bis(trimethylsilyl)methyl]-4-[tris(trimethylsilyl)methyl]phenyl], was systematically disclosed using cyclic
voltammetry and theoretical calculations. It was found that they showed reversible one-electron redox couples
in the reduction region. The anion radical species of the Bbt-substituted diphosphene and distibene were
successfully synthesized by the reduction of the corresponding neutral dipnictenes (BbtPPBbt and BbtSbSbBbt). Their structures were reasonably characterized by ESR, UV−vis, and Raman spectroscopy, and
the distibene anion radical was structurally characterized by X-ray crystallographic analysis.