Synthesis and spectroscopic properties of aniline tetramers. Comparative studies

A new synthetic method involving SNAr coupling of 4-fluoronitrobenzene to arylamines, followed by the reduction of the nitro groups, has been developed. Two types of aniline oligomers, namely Ph/NH2 and NH2/NH2 tetramers have been prepared by this method. Tetramers in the leucoemeraldine and in the emeraldine oxidation states were characterized by NMR, UV-Vis-NIR, IR and mass spectroscopies. It shown that the NH2/NH2 tetramer oxidized to the emeraldine state forms two isomers: syn and anti. The oxidation of the Ph/NH2 tetramer leads to the creation of positional isomers, depending on the synthetic method.