Synthesis and electrochemical properties of highly extended and sulfur-rich vinylogs as of tetrathiafulvalene

Using the reactivity of the carbonyl groups of 4,5-diformyl-1,3-dithiol-2-y lidene-substituted ethanals or ethanones with ylides or phosphonate anions, highly extended analogs of TTF 1 and 2 were synthesized by Wittig or Witti g-Horner reactions. Their excellent pi -donor properties, as well as the po ssibility of obtaining polycationic states, were confirmed by cyclic voltam metry. The structural study of cation-radical salt 1b beta gamma . PF6 reve als a two-dimensional network in the solid state.