Structural Change upon One-Electron Reduction of an Isolable Dialkylsilylene

Dialkyl(potassio)silyl radical 6a[K(18-crown-6)] and dialkylsilylene radical anion 6b[K([2.2.2]cryptand)] were synthesized by the one-electron reduction of dialkylsilylene 5 and characterized by X-ray diffractional analysis and EPR spectroscopy. The structural change from 5 to 6b upon the one-electron reduction can be explained by reduced σ(Si–C) → 3p(Siα) orbital interactions.