PALLADIUM AND NICKEL CATALYZED POLYCONDENSATION - THE KEY TO STRUCTURALLY DEFINED POLYARYLENES AND OTHER AROMATIC POLYMERS

This article provides an overview on a new and easy to perform Ni- and Pd-catalyzed polycondensation of various kinds of homo- and heteroaromatic monomers. It allows the regiospecific coupling of these monomers at predetermined positions to furnish the corresponding structurally perfect polyarylenes, which up to now have only been known as ill-defined, generally insoluble and infusible materials. The compatibility of this method towards functional groups is excellent. The achievable degrees of polymerization range from 20 to 60. The solubility and characterizability of the polymers is ensured, if necessary, by the attachment of flexible alkyl, tert.-butyl, or alkoxy chains to the monomers. Results of initial physicochemical measurements with some of the polymers and their respective model compounds are briefly discussed. They do not only give vital clues to the intrinsic properties of poly- and oligoarylenes but also disclose exciting, unprecedented properties of these materials.