CRYSTAL-STRUCTURE AND ELECTRICAL PROPERTY OF (BEDT-TTF)(5)[PT(SCN)(4)]

The crystals of (BEDT-TTF)(5)[Pt(sCN)(4)] (BEDT-TTF:4,5:4',5'-bis (eth ylenedithio)-tetrathiafulvalene), C54H40. N4PtS44, belong to the monoc linic space group P2(1)/c, with the lattice constants of a = 18.166(4) Angstrom, b = 11.437(2) Angstrom, c = 21.040(7) Angstrom, beta = 111. 17(2)degrees, V = 4076.3(16) Angstrom(3) and Z = 2. The structure is r efined to R = 0.061 for 6441 independent reflections. The crystal stru cture consists of the donor layers and the anion layers alternating al ong the a axis. BEDT-TTF molecules are stacked face to face along the c axis to form a pentamer. In the anion layer, [Pt(SCN)(4)](2-) anions lay parallel to the be plane and four SCN ligands coordinate to one P t atom at sulfur atoms with Pt-S-CN bond angles of about 110 degrees. This salt exhibits semiconducting behavior with the activation energy value of about 0.18 eV in the temperature dependence of the resistivit y.