Synthesis and properties of methylthio substituted ST-TTP derivatives

A new ST-TTP donor TMEO-ST-TTP, where TMEO-ST-TTP is 2-[4,5-bis(methylthio) -1,3-diselenol-2-ylidene)-5-(4,5- ethylendioxy-1,3-dithiol-2-ylidene)-1,3,4 ,6-tetrathiapentalene, has been prepared. It affords highly conducting PF6- and AsF6- salts retaining metallic conductivity down to 4.2 K, while the T CNQ complex and ClO4- salt are low conductive semiconductors. X-Ray structu re analyses reveal that (TMEO-ST-TTP)(TCNQ)(PhCl) has a DA type mixed stack , and that the donor array of (TMEO-ST-TTP)(2)ClO4(DCE) in the conducting s heet resembles beta-BEDT-TTF salts.