Synthesis, crystal structures and properties of new radical cation salts based on some tetrathiapentalene derivatives with halogenomercurate anions

New radical cation salts of BDH-TTP [2,5-bis(1,3-dithiolan-2-ylidene)-1,3,4,6-tetrathiapentalene], BDA-TTP [2,5-bis(1,3-dithian-2-ylidene)-1,3,4,6-tetrathiapentalene] and DTDH-TTP [2-(1,3-dithiol-2-ylidene)-5-(1,3-dithiolan-2-ylidene)-1,3,4,6-tetrathiapentalene] with halogenomercurate anions have been prepared. X-ray analysis at 120 K revealed the κ-type arrangement of conducting donor layers in (BDH-TTP)4Hg3Br8 and (BDH-TTP)4Hg3Cl8, and the β-type packing of donor layers in the (BDA-TTP)4Hg2Br6, (BDA-TTP)6Hg4I10.34 and (DTDH-TTP)6Hg3Br9 radical cation salts. The crystals of κ-(BDH-TTP)4Hg3Br8, κ-(BDH-TTP)4Hg3Cl8 and β-(DTDH-TTP)6Hg3Br9 behave as metals down to liquid helium temperatures, the resistivity of BDA-TTP salts shows semiconducting temperature dependence.