The higher homologues of triphenylamine: Model compounds for poly(N‐phenyl‐1,4‐phenyleneamine)

Well‐defined model compounds of poly(N‐phenyl‐1,4‐phenleneamine)(2), the dimer5, the trimer6and the tetramer7, were prepared by stepwise synthesis. Cyclic voltametry and the mass spectra demonstrate the high stability of the radical cations from the model compounds. The UV spectra show that there is some conjugation through the lone electron pair at the nitrogen atom, but the amount of conjugation is rather small. Oligo(N‐phenyl‐1,4‐phenyleneamine)(2)with an average degree of polymerization of 10 was prepared by metalation ofN,N′‐diphenyl‐1,4‐phenylenediamine and subsequent reaction with 1,4‐diiodobenzene.