No abstract

No abstract

Electro-oxidation of a solution of [AcrH][Ni(dmit) 2 ] (AcrH ) acridinium; dmit ) 2-thioxo-1,3-dithiole-4,5dithiolate) yields black crystals of [AcrH][Ni(dmit) are obtained by slow interdiffusion of solutions of PheHBF 4 and [Bu 4 N][Ni(dmit) 2 ]. Crystals of 1 are monoclinic, of space group C2/c, with a ) 39.124(3) Å, b ) 6.4777(5) Å, c ) 20.621(1) Å, β ) 110.55(1)°, and Z ) 4. Crystals of 2 are triclinic, of space group P1 h, with a ) 5.7795(6) Å, b ) 12.056(1) Å, c ) 19.041(1) Å, R ) 71.98(1)°, β ) 89.47( 1)°, γ ) 77.99(1)°, and Z ) 1. The crystal structures of the two compounds are very different. In compound 2, regular stacks of slightly dimerized Ni(dmit) 2 units are found and short S‚‚‚S interactions are found in two dimensions. Compound 1, however, shows stacks built from trimers of Ni(dmit) 2 units, which are rotated 30°toward each other, forming a "spanning overlapping mode". Short S‚‚‚S interactions are found in all three dimensions. Compound 1 shows a room-temperature conductivity of 45 S‚cm -1 and metallic conductivity behavior from room temperature down to 0.4 K. No superconductivity is observed at high pressures of 8 and 13 kbar. Compound 2 shows a room-temperature conductivity of 4 S‚cm -1 and semimetallic conductivity behavior from room temperature down to 100 K. The measured conductivity behaviors are in good agreement with the results obtained from band-structure calculations according to a tight-binding model and including Coulomb repulsion.