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+

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(o), while the TCNQ anions crystallize as [TCNQ]2 2- dimers with an interplanar separation of 3.16 A. 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(o), 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(o), while the other two are near 90(o) (81-100(o).