SYNTHESIS AND CHARACTERIZATION OF [ACRIDINIUM][NI(DMIT)(2)](3) AND [PHENAZINIUM][NI(DMIT)(2)](3) (DMIT = 2-THIOSO-1,3-DITHIOLE-4,5-DITHIOLATE)

Electro-oxidation of a solution of [AcrH][Ni(dmit)(2)] (AcrH = acridin ium; dmit = 2-thioxo-1,3-dithiole-4,5-dithiolate) yields black crystal s of [AcrH][Ni(dmit)(2)](3) (1). Black crystals of [PheH][Ni(dmit)(2)] (3) (2) (PheH = phenazinium) are obtained by slow interdiffusion of so lutions of PheHBF(4) and [Bu4N][Ni(dmit)(2)]. Crystals of 1 are monocl inic, of space group C2/c, with a = 39.124(3) Angstrom, b = 6.4777(5) Angstrom, c = 20.621(1) Angstrom, beta = 110.55(1)degrees, and Z = 4. Crystals of 2 are triclinic, of space group P (1) over bar, with a = 5 .7795(6) Angstrom, b = 12.056(1) Angstrom, c = 19.041(1) Angstrom, alp ha = 71.98(1)degrees, beta = 89.47(1)degrees, gamma = 77.99(1)degrees, and Z = 1. The crystal structures of the two compounds are very diffe rent. In compound 2, regular stacks of slightly dimerized Ni(dmit)(2) units are found and short S ... S interactions are found in two dimens ions. Compound 1, however, shows stacks built from trimers of Ni(dmit) (2) units, which are rotated 30 degrees 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 temperatu re down to 0.4 K. No superconductivity is observed at high pressures o f 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 agreem ent with the results obtained from band-structure calculations accordi ng to a tight-binding model and including Coulomb repulsion.