Rational Control of Electronic Structure and Lattice Architecture in Electrically Conducting Molecular/Macromolecular Assemblies

摘要

This article discusses an approach to control molecular stacking interactions in low-dimensional mixed molecular assemblies by locking partially oxidized metallomacrocycles together in a face-to-face orientation. Thus, doping of the cofacially linked polymers M(Pc)O sub n (M = Si, Ge, Sn; Pc = phthalocyaninato) with halogen (I2, Br2) or quinone (e.g., DDQ, TCNQ) electron acceptors produces robust, electrically conductive polymers with a wide range of stoichiometries and properties. The new materials have been studied by a variety of physical methods including X-ray diffraction, resonance Raman and infrared spectroscopy, ESR, static magnetic susceptibility, variable-temperature four-probe d.c., electrical conductivity, and voltage-shorted compaction techniques. Evidence is presented that some of the macromolecules have metal-like conductivity in the stacking direction and that transport properties within the series can be readily manipulated by rational variation of lattice architecture (e.g., the identity of the metal, M) and acceptor characteristics. Insight into those acceptor properties which stabilize the mixed valent state is provided. (Author)