Charge-transfer (CT) complexes frequently have much higher
electrical conductivities than their components alone and an
approach to electrically conducting polymers is based on the
formation of polymers carrying pendant donor and acceptor groups from which a number of possible arrangements arise, each relying on the charge-transfer interactions between the donor and acceptor groups. Of particular interest were the possible CT complexation characteristics of the phthalimido group in conjunction with a number of electron donors in polymer based systems. Donor substituents were selected from polynuclear aromatic groups based on the anthracene and phenanthrene nucleii, and also from methoxy-substituted phenols and anilines.
A series of vinyl monomers based on acrylic and methacrylic
esters and amides were synthesised with the appropriate donor and acceptor functionalities incorporated in the ester/amide groupings. From these, via radical polymerisation, a range of polymer donor-acceptor (D-A) systems were prepared. Investigation of their CT complex characteristics by U.V. absorption spectroscopy revealed the phthalimido group to behave as a poor electron acceptor - no complexation was observed between the phthalimido compounds and the various donor systems. The absence of any complexation was also confirmed by their high electrical resistivities, estimated to be at least greater than 109 ohm-cm.