2-(5,6-difluoro-3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile is also named 2FIC. It is a strong electron-withdrawing molecule and can react with aldehydes through the Knoevenagel condensation reaction, which allows product absorption to extend to the near-infrared region through intramolecular charge transfer between strongly electron molecules and strong electron absorber molecules. It can be used to make organic solar cells, improving the power conversion efficiency and fill factor of batteries[1-2].
2-(5,6-Difluoro-2,3-dihydro-3-oxo-1H-inden-1-ylidene)propanedinitrile is incorporated into the core of photovoltaic devices to achieve higher current and reduced energy loss for nonfullerene solar cells.
[1] Design, Synthesis, and Photovoltaic Characterization of a Small Molecular Acceptor with an Ultra‐Narrow Band Gap. DOI: 10.1002/anie.201610944.
[2] Facile synthesis of high-performance nonfullerene acceptor isomers via a one stone two birds strategy. DOI: 10.1039/c9ta07917c.
