2-Dicyanomethylene-1,3-Dithiole-4,5- Dithlolate-A New Dithiolene Ligand and Its Metal Complexes

Abstract

Abstract 2-Dicyanomethylene-1,3-dithiole-4,5-dithiolate (DCDD) has been prepared and used for the synthesis of transition metal complexes (Bu4N)2[M(DCDD)2], M = Ni, Cu, Zn. The redox properties of the nickel complex are similar to that of (Bu4N)2[Ni(dmit)2] (dmit: 1,3-dithiole-2-thione-4,5 dithiolate). Oxidation of (Bu4N)2[Ni(DCDD)2] yields the monoanionic complex Bu4N[Ni(DCDD)2] the electron spectrum of which is characterized by a strong NIR absorption at 1135 nm. The crystal structure of Bu4N[Ni(DCDD)2] shows the anion to be almost planar. Face-to-face stacking of the anions with alternating Ni-Ni distances results in a columnar structure of dimeric anions. The spins of the anions within a dimer are anti-ferromagnetically coupled. The complex Fc*[Ni(DCDD)2] (Fc*: decamethyl-ferrocene) has been prepared by a metathesis reaction using Fc*BF4.