A series of mu-tto-(tto=C2S42-=tetrathiooxalato) bridged bimetallic Ni(II) complexes with the general formula (Y)(2){ttO[Ni(L)](2)} (where Y = Bu4N+, L = dsit = C3Se2S32-=2-thioxo-1,3-dithiole-4,5-diselenolato (2) and dmise=C3SeS42-=2-Selenoxo-1,3-dithiole-4,5-dithiolato (3); and where Y=Me4N+ (4) and Et4N+ (5), L=dmit=C3S52-=2-thioxo-1,3-dithiole-4,5-dithiolato) have been synthesized. The single-crystal X-ray structures of 2, 3, 4 and 5 have been determined: 2, (Bu4N)(2){tto[Ni(dsit)](2)}, monoclinic, space group P2(1)/c, a=9.8893(1) 17.8825(2) Angstrom, beta=90.561(1)degrees, Z=2; 3, (Bu4N)(2){tto[Ni(dmise)](2)}, orthorhombic, 9.8286(2) Angstrom, beta=16.1741(3) Angstrom, c=34.3022(1) Angstrom, Z=4; 4, (Me4N)(2){tto[Ni(dmit)](2)}, monoclinic, space group C2/m, a=13.8043(4) Angstrom, b=10.1081(1) Angstrom, c=12.0483(3) Angstrom, beta=115.239(1)degrees, Z=2; 5, (Et4N)(2){tto[Ni(dmit)](2)}, monoclinic, space group P2(1)/n, a=11.8313(1) Angstrom, b=11.0172(2) Angstrom, c=15.3014-(1) Angstrom, beta=110.951(1)degrees, Z=2. All of the complexes presented are extensively conjugated and chalcogen-rich with (Bu4N)(2){tto[Ni(dsit)](2)} (2), (Bu4N)(2){tto[Ni(dmise)](2)} (3), and (Me4N)(2){tto[Ni(dmit)](2)} (4) also being planar as precursors to electrically conducting materials. The angle of the tto-Ni-L portion of the complexes varies with the choice of ligand and with the counterion. Cyclic voltammetry results of 2 and 3 each show a first low-potential reversible redox couple followed by a second nonreversible redox couple. The structural and electronic properties of 2-5 are compared to those of the recently communicated analogous complex, (Bu4N)(2)-{tto[Ni(dmit)](2)} (1). Electrocrystallization, interdiffusion, and chemical oxidation experiments with 1 Rave yielded black insoluble materials with high pressed powder conductivities of up to 0.5 S/cm.