Newly modified TTF and DSDTF donors for developing molecular-based organic metals

Abstract

The development of organic metals based on newly modified TTF (tetrathiafulvalene) and DSDTF (diselenadithiafulvalene) donors via the Lewis acid-promoted reactions of organotin compounds with electrophiles is described. The Me ₃ Al-promoted reaction is versatile for construction of 1,3-dichalcogenol-2-ylidene moieties, and the BF ₃ -promoted reaction is utilized to prepare the 1,3-dithiole-2-chalcogenone derivatives condensed with a bis-fused six-membered heterocycle. The use of these reactions enables us to synthesize DHTTF (dihydrotetrathiafulvalene) donors, DHTTF-fused donors, DSDTF donors incorporating the vinylenedithio end group, and TTF donors with an extended periphery by addition of aliphatic heterocycles. The crystal structures of radical-cation salts derived from these π-electron donors, including some new κ-type salts with a 2:1 (donor:anion) stoichiometry, are also disclosed.