Synthesis and characterization of photoactive amorphous molecular and polymeric pyridinium materials

摘要

Pyridinium materials both molecular and polymeric are interesting class of multifunctional electrolytes and polyelectrolytes, which exhibit liquid-crystalline and light-emitting properties. Moreover, their properties could be easily tuned simply by modifying the chemical structures of counterions.In this dissertation, we described the preparation and analysis of new ionic molecular materials based on bis(pyridinium salt)s and a new class of poly(pyridinium salt)s with various heterocyclic moieties in their backbones with various organic counterions. They were prepared by either ring-transmutation reaction or by metathesis reaction. Their chemical structures were confirmed by FTIR, 1H and 13C NMR spectroscopy and elemental analysis. They had excellent thermal stability comparable to many high performance polymers and high glass transition temperatures. These materials had good solubility in common organic solvents and, therefore, they could be efficiently processed into thin films and fibers. In some cases, the solubility of poly(pyridinium salt)s in organic solvents exceeded critical concentrations above which they exhibited lyotropic iv liquid-crystalline phases as determined with POM studies. The light-emission properties of these materials were examined by spectrofluorometry in both solution and film states. Their quantum yields were also assessed. The morphologies of films and hand-drawn fibers from both molecular and polymeric materials were thoroughly studied with POM, XRD, SEM and TEM techniques. These materials could be good candidates for high performance applications in the field of optoelectronics.