Synthesis and characterization of liquid crystalline perylene diimides

Several polyoxyethylene-substituted perylene-3,4,9,10-tetracarboxyldiimides have been synthesized and characterized. Relative to other known perylene diimide derivatives, all of the present compounds have much lower melting-points and much greater solubility in common solvents. Most of these compounds possess liquid crystalline properties over a wide range of temperatures, some of them even at room temperature and below. Some of the photophysical and self-organizing characteristics of these compounds are demonstrated, particularly with regard to the spontaneous formation of a highly crystalline black phase. Generalized correlations about the physical properties and the chemical structures of these new liquid crystalline compounds are discussed. Their unusual physical and photophysical properties have important implications for their use in a variety of electroactive and photovoltaic applications.