T. Michinobu et al., 3,4 '-bis[bis(t-butyl- and methoxy-phenyl)amino]stilbene bis(cation radical)s and their electrochemical and magnetic properties, B CHEM S J, 73(4), 2000, pp. 1021-1027
3,3'-Bis[bis(p-t-butylphenyl)amino]stilbene 1a and 3,4'-bis[bis(p-methoxyph
enyl)amino]stilbene 1b were synthesized. The oxidation of 1 was analyzed by
electrochemical measurements, which revealed the reversible formation of t
he bis(cation radical) 2 via a two-electron transfer reaction. The chemical
oxidation of 1 with NOBF4 also gave the bis(cation radical) 2; UV/vis and
ESR spectroscopies supported aminium radical formation without any side rea
ction. Magnetization, magnetic susceptibility, and the ESR Delta M-s = +/-2
signal of the biradicals indicated tripler ground states with a large trip
let-singlet energy gap.