Characterization of novel TCNQ and TCNE 1:1 and 1:2 salts of the tetrakis(dimethyamino)ethylene dication, [{(CH3)2N}2C–C{N(CH3)2}2]2+

Abstract

Addition of TCNQ to a solution of tetrakis(dimethylamino)ethylene in MeCN produces the salt [TDAE][TCNQ]₂; the dipositive cation, [{(CH₃)₂N}₂C–C{N(CH₃)₂}₂]²⁺, is nonplanar, with a dihedral angle of 63.9°, while the TCNQ anions crystallize as [TCNQ]₂^2– dimers with an interplanar separation of 3.16 Å. The complex [TDAE][TCNE] was prepared in a similar manner; the [TDAE]²⁺ cation and [TCNE]^2– anion are nonplanar, with dihedral angles of 71.3 and 76.6°, respectively. The four CN groups in the [TCNE]^2– anion each accept three C–H ⋯ N hydrogen bonds. In each case, one C–N ⋯ H angle is in the range 134–156°, while the other two are near 90°(81–100°).