Synthesis, oxidation and protonation of octamethyl-1,1 '-bipyrrole

2,2',3,3',4,4',5,5'-Octamethyl-1,1'-bipyrrole 6 is obtained from 3,4-dimeth ylhexane-2,5-dione 4 and hydrazine. Treatment of 6 with [NO]BF4 gives the r adical cation 11, while protonation at C-alpha occurs with HBF4 to yield th e bipyrrolium salt 13. Oxidation with I-2 results in a bipyrrolium iodide [ 6H(+)] I-3(-). 1/2I(2) (14). The X-ray structures of 6 and 14 are reported. Electrochemical oxidation of 6 proceeds in two one-electron steps, but is c omplicated by coupled slow chemical reactions. The oxidized species are sta ble on time scales shorter than several seconds. The primarily formed radic al cation 11, however, slowly abstracts a hydrogen atom, possibly from the solvent or the supporting electrolyte, to yield protonated bipyrrole 13. Th e complex reaction mechanism is supported by electrolysis experiments and s imulations of cyclic voltammograms.