%0 Journal Article %T Synthesis and Properties of 2-Alkylidene-1,3-dithiolo[4,5-d]-4,5-ethylenediselenotetrathiafulvalene Derivatives and Crystal Structures of Their Cation Radical Salts %A Keisuke Furuta %A Shuhei Kohno %A Takashi Shirahata %A Koya Yamasaki %A Shojun Hino %A Yohji Misaki %J Crystals %D 2012 %I MDPI AG %R 10.3390/cryst2020393 %X Tetrathiafulvalene derivatives condensed with 2-alkylidene-1,3-dithiole moiety, MeDTES (2-isopropylidene-1,3-dithiolo[4,5- d]-4,5-ethylenediselenotetrathiafulvalene), EtDTES (2-(pentan-3-ylidene)-1,3-dithiolo[4,5- d]-4,5-ethylenediselenotetrathiafulvalene), and CPDTES (2-cyclopentanylidene-1,3-dithiolo[4,5- d]-4,5-ethylenediselenotetrathiafulvalene) have been synthesized. Crystal structure analysis of MeDTES salts with Au(CN) 4 £¿, ReO 4 £¿, and I 3 £¿ and a CPDTES salt with I 3 £¿ reveals that the donor£¿anion ratios of all salts are 1:1. Band calculation of (MeDTES)[Au(CN) 4] suggests a quasi-one-dimensional Fermi surface that could be the result of the uniform stack of donor molecules. In spite of this stacking, the salt is a Mott insulator because of a large on-site Coulomb interaction U. (MeDTES)(ReO 4)(H 2O) 0.5 possesses Fermi points and exhibits semiconducting behavior with small activation energy ( E a = 0.058 eV). I 3 £¿ ions form disordered infinite chain in (MeDTES)(I 3)(DCE) 0.25, but those in (CPDTES)(I 3) exist as discrete ions. They show low conductivity (10 £¿4£¿10 £¿2 S cm £¿1) at room temperature and the band calculation suggests that they are band insulator. %K molecular conductors %K tetrathiafulvalene derivatives %K cation radical salts %K crystal structure %K band calculation %U http://www.mdpi.com/2073-4352/2/2/393