Aryl-bisalkynyl bridged perylene diimides dimers: Efficient synthesis, properties and improved electron mobilities

A series of aryl-bisalkynyl bridged perylene diimides derivatives were efficiently synthesized through the Sonogashira-type coupling reaction, and their photophysical, electrochemical and electron-transporting properties were investigated in detail. With the introduction of aryl-bisalkynyl groups, their absorption spectra exhibit extra strong absorption in the short wavelength region and therefore realizing broad wavelength range from 300 to 700 nm, which can overcome the weakness of narrow half-peak width of N,N'-bis(1-ethylpropyl)perylene-3,4,9,10-tetracarboxylic acid bisimides (PDI). The lowest unoccupied molecular orbital (LUMO) levels (about −4.00 eV) are lower than that of the prototype PDI, which make them potential for excellent electron-transporting materials. As a result, the improved electron mobilities of 10−4 cm2 V−1 s−1, which is three orders of magnitude higher than that of PDI, were obtained in space charge limited current (SCLC) devices.