Organic Electron Acceptors Comprising a Dicyanomethylene-Bridged Acridophosphine Scaffold

In spite of recent advancements in the area of organic n-type semiconductors, compounds with characteristics comparable to their p-type counterparts still remain rather scarce, mainly due to their often limited stability and... [ view full abstract ]

In spite of recent advancements in the area of organic n-type semiconductors, compounds with characteristics comparable to their p-type counterparts still remain rather scarce, mainly due to their often limited stability and poor solubility.[1]

In this work, stable two-electron acceptors comprising a dicyanomethylene-bridged acridophosphine scaffold were synthesized and the possibility to efficiently tune their reversible reduction potentials through derivatization of the phosphorus center was demonstrated.[2,3]  X-ray crystallographic analysis combined with NMR, UV/vis, IR spectroscopic, and electrochemical studies, supported by theoretical calculations, revealed the crucial role of the phosphorus atom for the unique redox, structural, and photophysical properties of these compounds. The results identify the potential of these electron deficient scaffolds for the development of functional n-type materials and redox active chromophores upon further functionalization.

[1] M. Stolar, T. Baumgartner, Phys. Chem. Chem. Phys. 2013, 15, 9007.

[2] T. A. Schaub, E. M. Zolnhofer, D. P. Halter, T. E. Shubina, F. Hampel, K. Meyer, M. Kivala, Angew. Chem. Int. Ed. 2016, 55, 13597.

[3] T. A. Schaub, S. M. Brülls, P. O. Dral, F. Hampel, H. Maid, M. Kivala, Chem. Eur. J. 2017, 23, 6988.