Synthesis of Novel Ladder Bis-Silicon-Bridged p-Terphenyls

The tetralithiation reaction of 2,2',5',2' '-tetrabromo-p-terphenyl followed by a double silacyclization produces bis-silicon-bridged p-terphenyls. On the basis of this convenient method, a series of new ladder-type p-terphenyl derivatives have been synthesized. Their crystal structures and photophysical properties are described.