The Structure of Fractionally Charged Tetracyanobenzenen− Present in [TCNB]₃²⁻

On a reduced charge: The reduction of 1,2,4,5-tetracyanobenzene (TCNB) with tetrakis(dimethylamino)ethylene (TDAE) forms [TDAE][TCNB]3⋅MeCN. Characterization reveals that the [TDAE]2+ ion is present, and that TCNB is reduced forming diamagnetic [TCNB]32−. The reduced TCNB units (see picture) are best described as [TCNB]≈0.5−[TCNB]≈1−[TCNB]≈0.5− containing fractionally charged organic species.