COFACIAL POLYMERS CONSTRUCTED FROM PHTHALOCYANINES. WHAT CAN THEY TEACH US ABOUT MOLECULAR METALS? .

Polymers of the type left bracket M(Pc)O right bracket //n, M equals Si,Ge,Sn; Pc equals phthalocyaninato, constitute a robust, structurally regular class of materials in which the building blocks for a family of highly conductive molecular metals are rigorously maintained in a cofacial stacking architecture. These features, in combination with chemical and electrochemical doping techniques, allow wider and more controllable variations in molecular metal crystal and electronic structure than has ever before been possible. In this lecture, we discuss how the electrical, optical, and magnetic properties of cofacially joined phthalocyanine molecular metals respond to changes in three key parameters: i) ring-ring interplanar spacing, ii) the nature of off-axis counterions, iii) the band-filling. The structural regularity of these materials also affords an informative picture of electrochemical doping mechanisms in conducting polymers and the solution processing characteristics of rigid-rod macromolecules.