Synthesis and characterization of some polyaniline-organic acceptor complexes

Abstract

The charge transfer (CT) interactions between polyemeraldine (PEM) and six organic electron acceptors were studied. The complexing ability of the acceptors, based on the maximum attainable electrical conductivity of the resulting complex, could be arranged in the following ascending order: tetrachloro-p-benzoquinone (p-chloranil), tetrafluoro-p-benzoquinone (p-fluoranil), tetrabromo-o-benzoquinone (o-bromanil), 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ), tetrachloro-o-benzoquinone (o-chloranil), and tetracyanoethylene (TCNE). Conductivity in the order of 10-1 S/cm was achieved in the PEM/TCNE complex. The complexes were also characterized by infrared (IR) absorption spectroscopy, thermogravimetric (TG) analysis, and X-ray photoelectron spectroscopy (XPS). In most complexes, the CT interactions have proceeded further than the formation of pure molecular complexes. However, the mechanism of CT interaction was found to be analogous to that of protonation of PEM by protonic acids.