| Description |
Organic charge transfer complexes have been known for decades, but have experienced a resurgence in recent years. This paper explores the properties of a cyano carbon molecule and its potential for use as an acceptor in charge-transfer complexes. Pentacyano-trifluoromethyl benzene [C6(CN)5CF3] was synthesized from octafluorotoluene and both sodium and potassium cyanide in a two step reaction under mild conditions, producing a stable Meisenheimer intermediate after the first step. The product was then paired with various anions and donor compounds to produce four new structures. Using crystallography, cyclic voltammetry, UV-VIS, IR, and NMR spectroscopic methods, insight into the character of these cyano compounds was gained. The crystal structure of the colorless neutral compound shows CF3/CN positional disorder, and packs in an edge-to-face manner in the solid state. When paired with DMA or perylene, [C6(CN)5CF3] forms deep blue charge transfer complexes with an alternating face-to-face donor-acceptor stacking pattern. The intermediate Na+[C6(CN)6CF3]- is bright red, and shows the carbon within the ring attached to the CF3 is tetrahedral while the rest of the ring remains planar. |
