Hexaaryl-carbo-benzenes revisited: a novel synthetic route, crystallographic data, and prospects of electrochemical behavior

Abstract

An improved 12-step synthetic route and full characterization of hexaphenyl-carbo-benzene (4, 8%) and the p-bis-3,5-di-tert-butylphenyl homologue (11, 4%), are described. The carbo-benzene reference 4 is now accurately described in the crystal state by X-ray diffraction analysis in the chiral space group P2₁2₁2₁, and in comparison to the less symmetric derivative 11 exhibiting a centro-symmetric packing. According to cyclic voltammetry, both hexaaryl-carbo-benzenes 4 and 11 can behave as both reversible potent electron acceptors and standard electron donors, with respective potentials of −0.73 ± 1 V and +1.17 ± 2 V/SCE, respectively. Due to their extremely low solubility, solid films of 11 fabricated using the “wet method”, with the initial view of studying charge transport properties, were found to display high roughness.