An efficient synthesis of ethylenedioxotetrathiafulvalene (EDO–TTF), a non-symmetrically substituted tetrathiafulvalene, is described together with that of the corresponding acid and amide derivatives, EDO–TTF–CO2H and EDO–TTF–CONRR' (R, R' = H, Me), whose redox potentials are also reported. The X-ray crystal structures of EDO–TTF and EDO–TTF–CO2H have been determined and the solid state arrangement of the two compounds compared with that of other TTF derivatives, such as EDT–TTF, EDT–TTF–CO2H and the parent symmetrically substituted BEDT–TTF and BEDO–TTF, revealing that a large number of sulfur atoms in the molecule stabilizes a face-to-face diad association through S⋯S van der Waals interactions with a characteristic bond-over-ring overlap while an increased number of light (C, H, O) atoms, as found in BEDO–TTF, leads to solid state associations reminiscent of the herring-bone pattern described for the smallest polynuclear aromatic hydrocarbons.