Synthesis of gem-tetraphenylethylene oligomers utilizing Suzuki reaction and their aggregation properties

Article abstract of DOI:10.1016/j.dyepig.2013.07.008

Four new gem-tetraphenylethylene-based oligomers were synthesized by Suzuki coupling reaction in good yields (62-80%) and characterized by NMR, mass spectrometer and elemental analysis. The absorption maxima of the synthesized oligomers in the solution possess similar absorption bands located at 328-332 nm. They are shown to be thermally stable and emit light in blue region (404-485 nm). All the oligomers are AIE-active, emit weakly in solutions with Φ_f values not exceeding 4%, become strong emitters in the aggregated states and the PL intensity values increase up to 18-fold. The results of CV measurements of the oligomers showed good reversibility, indicating that the compounds have good electrochemical stability. The HOMO values of the oligomers are in the range of -5.63 to -5.61 eV. The photoluminescence properties in aggregate-state and the high HOMO energy levels of these oligomers make them applicable as an active material for a light-emitting device.