Semi-conducting mixed-valent X(4)TCNQ(I-/II-)(X = H, F) charge-transfer complexes with C6H2(NH2)(4)

We report further characterisation on the previously described [C6H2(NH2)(4)][TCNQ] charge-transfer (CT) complex. An in-depth analysis of the crystallographic data aided by spectroscopic methods indicates the compound is mixed-valent with TCNQ(I-/II-)species. The analogous F(4)TCNQ CT complex has been synthesised and spectroscopic methods suggest that [C6H2(NH2)(4)][F(4)TCNQ] is also mixed-valent. Electrical conductivity measurements on both complexes indicate semi-conductor behaviour, with [C6H2(NH2)(4)][TCNQ] exhibiting a sigma(300K)= 9.8 x 10(-4)S cm(-1)and anE(a)= 0.10(1) eV. Density functional theory studies on both CT complexes reveal band structures suggestive of ambipolar transport, with a super-exchange mechanism.