Syntheses, structure and conducting properties of halogenated ethylenedioxytetrathiafulvalenes

4,5-Diiodo-, 4,5-dibromo-, and 4,5-dichloro-4',5'-ethylenedioxytetra-thiafulvalenes (EDO-TTFI2, EDO-TTFBr2, and EDO-TTFCl2) were synthesized in moderate to good yields by the two routes. The first route contains the reaction of EDO-TTF with LDA, followed by quenching with halogenated reagents, and the second route consists of the P(OR)(3)-mediated cross-coupling of 4,5-dihalogenated 1,3-dithiole-2-ones with 4,5-ethylenedioxy-1,3-dithiole-2-thione. The structures of EDO-TTFI2 and EDO-TTFCl2 were determined by X-Ray analysis. The radical-cation salts derived from EDO-TTFI2, EDO-TTFBr2, and EDO-TTFCl2 show high conductivities, although these compounds contain electron-withdrawing halogens as the substituent.