A New Generation of Nickel−dmit-Based Molecular Conductors Based on Fully Conjugated Bimetallic Complexes

We report the synthesis of a new completely planar, extensively conjugated bimetallic Ni(II) complex for the construction of new molecular metals. The complex, (Bu4N)2{tto[Ni(dmit)]2} (1), with 14 sulfur atoms in the periphery, has Ni(II) metal centers bridged by the tetrathiooxalate (tto) ligand and capped with dmit (dmit = C3S52- = 2-thioxo-1,3-dithiole-4,5-dithiolato) ligands. This is the first completely planar complex with tto bridging Ni(II) metal centers. Reaction of 1 with (TTF)3(BF4)2 forms a conducting material with a high pressed-pellet conductivity of 0.4 S/cm.