Silole-containing σ- and π-conjugated compounds
Synthesis, properties, and application of new σ- and π-electron systems consisting of the silole rings are described. A series of 2,5- and 1,1-difunctionalized siloles have been prepared based on the intramolecular reductive cyclization of diethynylsilanes. Starting from these functionalized siloles, oligo(2,5-silole)s and oligo(1,1-silole)s have been synthesized as model compounds for poly(2,5-silole)s and poly(1,1-silole)s, respectively, which are still veiled target molecules in this field. Some silole-containing π-conjugated cooligomers and copolymers with thiophene, pyrrole, and acetylene π-electron systems have also been prepared. They all have unique photophysical properties such as long-wavelength absorption in the UV/VIS absorption spectra. Some silole-based π-conjugated compounds have also been found to work as new useful materials for organic electroluminescent devices.