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Reaction of 2,4,6-tricyano-s-triazine (TCT) with tetrathiafulvalene (TTF) and N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD) leads to 1∶1 charge transfer complexes. The crystal structures of the TTF[TCT], as well as the decomposition product due to hydrolysis of the [TMPD][TCT], i.e. [HTMPD]+[2,4-dicyano-6-oxy-s-triazine]−, are reported and spectroscopically characterized.

Many of the Cm[TCNE]n (C = cation) salts have intradimer C–C interactions in the range of 2.9 to 3.5 A and show the electronic fingerprints associated with C–C bond formation (IR and UV spectra, magnetic properties, structural changes), despite the fact that two [TCNE]˙− anions should repel each other due to purely Coulombic considerations. Herein, we analyze these pairwise interactions in detail for a particular crystal in which such a C–C bond is found, to understand when and why these bonds are formed in a general case.

Reduction of tetracyanoethylene, TCNE, with tetrakis(n-propyl)ammonium iodide, [Pr4N]I, results in a new example of long π*-CC bonded π-[TCNE]22− dimers with a 2.870(4) A intradimer CC bond, which is structurally and spectroscopically characterized. This reaction also results in isolation of [Pr4N]2[TCNE][I3] possessing isolated [TCNE]˙− radical anions.

The reaction of [Et4N]I and tetracyanoethylene (TCNE) forms [Et4N]2[TCNE]2, which possesses [TCNE]22− with a 2.827(3) A intradimer CC bond distance and exhibits νCN at 2191, 2170 and 2163 cm−1, νCC at 1365 cm−1, and UV-Vis bands at 26 150 and 16 850 cm−1.