Interplay of Charge Transfer, Dimensionality, and Amide Hydrogen Bond Network Adaptability in TCNQF4 Complexes of EDO-TTF-CONH2 and EDT-TTF-CONH2

[EDO-TTF-CONH2][TCNQF4], triclinic system, space group P-1, a=8.2479(12) A˚, b=12.282(2) A˚, c=12.6842(18) A˚, α=113.850(17)°, β=106.420(17)°, γ=90.284(19)°, V=1116.8(4) A˚3; and [EDT-TTF-CONH2]2[TCNQF4], triclinic system, space group P-1, a=6.5858(9) A˚, b=11.699(2) A˚, c=12.2281(18) A˚, α=104.000(19)°, β=93.611(17)°, γ=98.279(19)°, V=899.9(3) A˚3, whose π-donor molecules, (ethylenedioxo)-carbamoyltetrathiafulvalene and (ethylenedithio)-carbamoyltetrathiafulvalene, respectively, differ solely by the nature of the chalcogen atoms in their outer ethylene dichalcogeno bridge, yet form very different charge-transfer complexes with the same π-acceptor. [EDO-TTF-CONH2•+]2 [TCNQF4•−]2 is a diamagnetic insulating ionic salt with a three-dimensional rock-salt-type structure based on discrete dimers while in the semi-conducting mixed-valence complex, [EDT-TTF-CONH2]2•+[TCNQF4•−], the mixed-valence dimers aggregate into infinite chains interspersed within parallel rows of non-interacting radical anions. It is shown how the robust and adaptable supramolecular amide hydrogen bond tweezers-like motifs common to the two solids simply comply to the 3-to-1 dimensionality reduction upon substitution of O for S. [Copyright &y& Elsevier]