Radical Cations of Bilayer Nanographenes.

Chemical redox reactions of bilayer nanographene complexes, (C 96 H 24 Ar 6 ) 2 (Ar = 2,6-dimethylphenyl) ( 1 2 ) and (C 42 H 12 R 6 ) 2 (R = t Bu) ( 2 2 ), were investigated. Upon two-electron oxidation reactions, 1 2 and 2 2 were transformed to radical cations 1 2 2•+ and 2 2 2•+ , respectively. SQUID and EPR measurements on 1 2 2•+ and 2 2 2•+ indicate that they possess an open-shell singlet ground state with antiferromagnetic interactions between two layers. The shortest separation distance between bilayers in 2 2 2•+ (3.30 Å) is shorter than that in 2 2 (3.44 Å) and 2 2 •+ (3.40 Å), illustrating stronger interaction upon loss of electrons.