C₄ Cumulene and the Corresponding Air‐Stable Radical Cation and Dication

Abstract

Abstract A neutral C 4 cumulene 1 that includes a cyclic alkyl(amino) carbene (cAAC), its air‐stable radical cation 1 .+ , and dication 1 2+ have been synthesized. The redox property of 1 .+ was studied by cyclic voltammetry. EPR and theoretical calculations show that the unpaired electron in 1 .+ is mainly delocalized over the central C 4 backbone. The commercially available CBr 4 is utilized as a source of dicarbon in the cumulene synthesis.