Synthesis and acid-responsive electron-Transfer disproportionation of non- and tetramesityl-substituted 1,1',9,9'-bicarbazole

Non-substituted 1,1',9,9'-bicarbazole and 3,3',6,6'-Tetramesityl- 1,1',9,9'-bicarbazole were synthesized through dimerization of carbazole derivatives and oxidative NN bond formation reaction. Non-substituted 1,1',9,9'-bicarbazole formed a stacking packing structure in crystal. Both bicarbazoles were found to undergo acid-responsive electron-Transfer disproportionation. The radical cation generated from the non-substituted 1,1',9,9'- bicarbazole was stable in solution under air at room temperature, even without protecting bulky substituents.