Mixed-valence bis(ethylenedithio)tetrathiafulvalenium (BEDT-TTF) monolayers sandwiched between extended close-packed Keggin-type molecular metal oxide cluster arrays: synthesis, unprecedented acentric structure, and preliminary conducting and e.s.r. properties of (BEDT-TTF)8SiW12O40

The synthesis, acentric sandwich structure, and preliminary electronic properties of conducting plate-like single-crystals of a 3,4;3′,4-bis(ethylenedithio)-2,2′,5,5′-tetrathiafulvalene (BEDT-TTF) salt of the tetravalent 12-tungstosilicate molecular anion SiW12O404– are described as well as evidence for a correlation between the non-centrosymmetrical character of the bi-dimensional solid and that of the discrete molecular cluster anion.