This book constitutes the Proceedings of the NATO Advanced Research Workshop on Conjugated Polymers held at the University of Mons, Belgium, during the first week of September 1989. The Workshop was attended by about fifty scientists representing most of the leading research groups within NATO countries, that have contributed to the development of conjugated polymeric materials. The program was focused on applications related to electrical conductivity and nonlinear optics. The attendance was well balanced with a blend of researchers from academic, industrial, and government labs, and including synthetic chemists, physical chemists, physicists, materials scientists, and theoreticians. The Workshop provided an especially timely opportunity to discuss the important progress that has taken place in the field of Conjugated Polymers in the late eighties as well as the enormous potential that lies in front of us. Among the recent significant developments in the field, we can cite for instance: (i) The discovery of novel synthetic routes affording conjugated polymers -that are much better characterized, especially through control of the molecular weight; - that can be processed from solution or the melt; the early promise that conducting polymcrs would constitute materials combining the electrical conductivities of metals with the mechanical properties of plastics is now being realized; -that can reach remarkably high conductivities.

This book constitutes the Proceedings of the NATO Advanced Research Workshop on Conjugated Polymers held at the University of Mons, Belgium, during the first week of September 1989. The Workshop was attended by about fifty scientists representing most of the leading research groups within NATO countries, that have contributed to the development of conjugated polymeric materials. The program was focused on applications related to electrical conductivity and nonlinear optics. The attendance was well balanced with a blend of researchers from academic, industrial, and government labs, and including synthetic chemists, physical chemists, physicists, materials scientists, and theoreticians. The Workshop provided an especially timely opportunity to discuss the important progress that has taken place in the field of Conjugated Polymers in the late eighties as well as the enormous potential that lies in front of us. Among the recent significant developments in the field, we can cite for instance: (i) The discovery of novel synthetic routes affording conjugated polymers -that are much better characterized, especially through control of the molecular weight; - that can be processed from solution or the melt; the early promise that conducting polymcrs would constitute materials combining the electrical conductivities of metals with the mechanical properties of plastics is now being realized; -that can reach remarkably high conductivities.

The polydiacetylenes are a class of polymers that are attrac ting increasing attention worldwide. There are many reasons for this interest one of the most important being the availability of many polydiacetylenes as macroscopic, high quality, single crystals. This fact was first reported in the pioneering work of Prof. G. Hegner on the solid-state polymerization of disub stituted diacetylenes in the late 1960s. Since then studies of the polymerization process and the properties of monomers and polymers have advanced understanding of solid-state reactivity and the physiCS of quasi-one-dimensional materials. More recently work on soluble polydiacetylenes, gels and films has been of interest for both academic and technological reasons. Progress in this area has required a combination of research disciplines ranging from synthetic organic chemistry to solid state physics. The interdisciplinary effort required for success ful research in polydiacetylenes was reflected in the mix of chemists, physicists and materials scientists who attended the Workshop. The emerging potential for commercial applications of polydiacetylenes was also evident in the nearly equal partici pation of academic and industrial/government scientists. The WOrkshop was the first major international meeting to focus solely on polydiacetylenes. It provided a forum in which problems of mutual interest could be discussed by scientists with diverse backgrounds and interests. It also satisfied the need for a review of the science of these materials at a time when this basic understanding is leading to technological applications."