Synthesis, optical and electrochemical characterization of lnter-ring bridged tetramers based on thiophene

Tetramers based on thiophene and phenylene residues in which the torsion angles between thiophene rings are locked by a chemical bridge have been synthesised by organosynthetic routes. The effect of locking on photoluminescence and absorption in solution has been studied. An enhanced tendency of doubly locked tetrathiophene to aggregate together with its facile decomposition upon light exposure greatly influence the luminescence properties.