Synthesis and characterization of X-shaped oligo（para-phenylene） derivatives functionalized with fluorene ethynylene

A series of linear and X-shaped oligo（para-phenylene） derivatives functionalized with fluorene ethynylenes 1,3 and 4 were synthesized through sequent Sonogashira coupling and Suzuki-Miyaura reaction in high yield.The electron-donating group-OCH3 and electron-withdrawing counterparts-CF3 were introduced to tune the spectra properties of compounds 3 and 4.The detail investigation of their photophysical properties in solution and film indicated that the introduction of both -OCH3 and -CF3 makes maximum emission distinct red-shift in comparison with parent compound 1,but the latter more prominently.