Strong one-electron oxidizing agents are of great synthetic utility, providing access to highly reactive target molecules. However, it is challenging to find a good balance between oxidation power, absence of side reactions, ease of handling and availability of the reagents. For example, inorganic fluorine compounds like (gaseous) AsF 5 or metal hexafluorides are extremely powerful oxidants e.g. in liquid SO 2 , but they can often not be handled in standard laboratories. In their seminal review on chemical redox agents, Connelly and Geiger discussed more popular reagents, e.g. Ag + and NO + , ferrocenium and triarylaminium salts. They classified all reagents with redox potentials E > +0.8 V vs. Cp 2 Fe as very strong oxidants. However, it has to be stated, that especially in combination with transition metal complexes, the use of Ag + or NO + can lead to side reactions. Interestingly, the oxidation power of Ag + can be significantly increased in combination with elemental halogens X 2 (X=Cl, Br, I), since the formation of insoluble AgX provides an additional driving force. Another highly useful system was developed by Poleschner. By using XeF 2 in combination with fluoride acceptors (BF 3 •Et 2 O, Me 3 SiOTf, etc.) different weakly-coordinating anions can be introduced. Jenne demonstrated the very high oxidation power of the boron cluster radical Me 3 NB 12 Cl 11 , however its multi-step synthesis seems to have prevented widespread use by other groups. The same is true for Michl's CB 11 Me 12 or a perfluorinated ammoniumyl cation of the Krossing group. In contrast to this, cyanocarbons, although mild oxidants, are often commercially available and air-stable. Due to the electronwithdrawing character of the cyano groups, neutral cyanocarbons are molecules with high electron affinities. Consequently, they easily form radical anions (or even dianions) of significant stability when treated with a reducing agent. This has led to a plethora of applications, e.g. in molecular magnetism and for the doping of organic polymers. Since tetracyanoquinodimethane (TCNQ) is only a mild oxidant (first reduction potential E = -0.30 V, second reduction potential E = -0.88 V vs. Cp 2 Fe) we assumed that its electron affinity could be increased and manipulated by coordination of Lewis acids to the terminal nitrogen atoms. Tris(pentafluorophenyl)boron is a commercially available and potent Lewis acid. It has a high affinity for hard donor atoms, e.g. nitrogen, but is typically non-oxidizing. Indeed, the reduction to its radical anion is only achieved at redox potentials below E = -1.7 V vs. Cp 2 Fe. Interestingly, it has been shown by Stephan and Erker that the combination of two equivalents of B(C 6 F 5 ) 3 with the electron acceptor p-benzoquinone C 6 H 4 O 2 is able to oxidize decamethylferrocene to its cation. Depending on the stoichiometry [C 6 H 4 O 2 •2 B(C 6 F 5 ) 3 ] -/2-mono-or dianions are obtained. By choosing other Lewis acids, the oxidation power of the system can be tuned. Another example for cooperative effects between electron acceptors and fluorinated Lewis acids is the combination of dioxygen with two equivalents of B(C 6 F 5 ) 3 which is even able to oxidize air-stable ferrocene to ferrocenium under formation of [(C 6 F 5 ) 3 BOOB(C 6 F 5 ) 3 ] 2-dianions. In general the mono-and dianions look very similar on the first sight since the four cyano groups are slightly tilted out of the plane of the central six-membered ring. However, several characteristic trends regarding specific bond lengths of the TCNQ core can be noticed. Neutral TCNQ displays significant variations regarding the C-C bond lengths in its six-membered ring due to its quinoidal nature. However, upon reduction to its mono-and (aromatic) dianion, these differences are becoming less pronounced. The same trend is observed for the adducts [TCNQ•4 B(C 6 F 5 ) 3 ] 0 / ꟷ/2ꟷ (Fig. Table . Experimental (all four crystal structures) and calculated (B3LYP-GD3BJ/Def2-SVP) bond lengths in Å for [TCNQ•4 B(C 6 F 5 ) 3 ] 0/ꟷ/2ꟷ , labels a to f according to Figure . ). In contrast, the shift of the antisymmetric ṽ(C≡N) vibration (which is lowest in energy) is much more pronounced (23112290 2221 cm ꟷ1 ). Indeed, the experimental IR spectra of salts that contain the monoanions have two bands at 2290 and ≈2250 cm -1 , while two bands at 2284 and ≈ 2205 cm -1 are observed for the dianion (Fig. ). The widening of the range of ṽ(C≡N) frequencies upon reduction is consequently both experimentally and computationally found. Attempts to measure Raman spectra of the products were unsuccessful due to decomposition or intense fluorescence.