One-Electron Oxidation of an Organic Molecule by B(C₆F₅)₃; Isolation and Structures of Stable Non-<i>para</i>-substituted Triarylamine Cation Radical and Bis(triarylamine) Dication Diradicaloid

The methylene-bridged triphenylamine 2 has been oxidized to planar radical cation 2•+ by B­(C6F5)3 or Ag+. Further reaction of 2•+[Al­(ORF)4]− and 2 with trace amounts of silver salt resulted in dication 32+, providing a rare example of structurally characterized bis­(triarylamine) “bipolarons”. 32+ can be directly prepared by the reaction of 3 with 2 equiv of Ag+. X-ray structural analysis together with theoretical calculation shows that 32+ has singlet diradical character and is analogous to Chichibabin’s hydrocarbons.