|
Fused conjugated heterocycles such as dithienothiophene and diselenothiophene have received a great attention as an organic semiconductor for applications to a broad spectrum of organic electronics. Recently, thienothiophenes or dithienothiophenes successfully applied to fused-nonfullerene acceptors as a donor unit and greatly contributed to boost organic solar cell efficiency. We developed a highly efficient synthetic routes, carried out opto-physical studies, and theoretical study based on DFT calculations. Interestingly, the selenium analog substituted with p-tert-butylphenyl shows much red-shifted λmax (387 nm) than sulfur analog does (373 nm). The bandgaps of both compounds based on these optical properties were determined as 2.88 eV and 2.97 eV respectively. In addition, the onset oxidation potentials (Eoxonset) of both compounds derived from the cyclovoltammograms were measured as 1.10 eV and 1.26 eV, respectively, which is well agreed with the optical properties observed from these compounds. DFT calculations reveals that the fused cores of both systems are highly plated and well-delocalized HOMO orbitals of the conjugated π systems. Synthetic details, optical & electrochemical studies, and the results of DFT calculations will be described in this presentation.
|
KCS