We have found that the short-step synthesis of TTF-fused donor systems including new ones such as DHTTF-TTF,DTDT-TTF,and DSDTF-TTF fused donors is sffected via the Me_3 Al-promoted reaction of the tin-masked dithiolate and esters. Ten kinds of new metallic charge-transfer complex and salts could be cbtained from DHTTF-TTF donors. Particularly, an X-ray structure analysis of the metallic (EDDH-TTP)_2AuI_2 salt (sigma_<rt>=14S/cm) atable down to 4.2 K has revealed that EDDH-TTP is the first TTF-fused donor producing a kappa-type 2 : 1 salt ; note that many organic superconductors are of this structure. Despite the presence of a flexible trimethylenedithio group, the DTDT-TTF fused donor system provided seven kinds of new molecular-based organic metals. We have also succeeded in preparing four kinds of new organic metals from DSDTF-TTF fused donors.
In addition, the synthertic route to a new TTF family with extended periphery by addition of several heterocycles has been developed via the BF_3-promoted reaction of tin dithiolates with 1,2-dihaloheterocycles. Although this new TTF family has a bulky and nonplanar structure, the dioxane-, dithiane-, and dioxolane-appended TTF derivatives belonging to this family have found to produce metallic radical-cation salts.