Synthesis and properties of the [formula omitted] complex of 1,4,7,10,13,16-hexaoxacyclooctadecane with potassium perchlorotriphenylmethide

Abstract

The 1 1 complex of 1,4,7,10,13,16-hexaoxacyclooctadecane with potassium perchlorotriphenylmethide has been prepared by reaction, in the presence of 18-crown-6, of (C 6Cl 5) 3CH with KOH or reduction of radical (C 6Cl 5) 3Ċ with K metal. Its structure as revealed by X-ray diffraction can be described as a separated ion pair of a (C 6Cl 5) 3C − carbanion and a potassium ion coordinated with the 18-crown-6; the carbanion has sp 2 hybridization and there is weak negative charge delocalization into the aromatic ring. The electronic spectra of alkaline salts of (C 6Cl 5) 3C − in various media provides evidence about the nature of the species present in solution. Electron-transfer reactions of (C 6Cl 5) 3C − with O 2, and several organic acceptors are described. Thermal decomposition of the solid crowned salt under an inert atmosphere involves decomplexation of the 18-crown-6 and a one-electron-transfer from the carbanion to the potassium counterion.