New Fulvalenium Salts of Cobalt Bis(dicarbollide): Crystal Structures and Electrical Conductivities

New radical cation salts (BEDT-TTF)[8,8',(7)-Cl-2(Cl-0.09)-3,3'-Co(1,2-C2B9H9.91)(1',2'-C2B9H10)] (1), (BEDT-TTF)[8,8'-Br0.75Cl1.25-3,3'-Co(1,2-C2B9H10)(2)] (2), and (BMDT-TTF)(4)[8,8'-Br-1.16(OH)(0.72)-3,3'-Co(1,2-C2B9H10.06)(2)] (3) were synthesized, and their crystal structures and electrical conductivities were determined. All the radical cation salts are semiconductors. Compounds 1 and 2 were found to be isostructural, however their electrical conductivities strongly differ (sigma(293) = 2 Omega(-1)cm(-1) and 10(-5) Omega(-1)cm(-1), respectively).