Synthesis, photophysical and electrochemical properties of a new star-shaped molecule with a 1,3,5-triethynylbenzene core and diketopyrrolopyrrole arms

A new star-shaped small molecule BDPP-1 based on 1,3,5-triethynylbenzene as a core and diketopyrrolopyrrole (DPP) as rigid arms have been successfully designed and synthesized. The thermal stability, photophysical and electrochemical properties were explored. The synthesized star-shaped small molecule BDPP-1 exhibited excellent solubility, high thermal stability, broad and strong absorption, narrow band gap and appropriate molecular levels. Moreover, the photoinduced charge separation process between the synthesized donor and acceptor PC(61)BM was evaluated by the fluorescence quenching experiment, revealing that the donor material BDPP-1 possessed efficient photoinduced charge separation performance. These detailed investigations on the structure-property relationship of the novel star-shaped molecule revealed that BDPP-1 is a prospective candidate as a donor material for organic photovoltaic materials.