Nickel complexes of 1,2-bis(diisopropylphosphino)ethane with sulfur-containing ligands

Abstract

The complex [NiBr₂(dippe)]1[dippe = 1,2-bis(diisopropylphosphino)ethane] reacted with benzene- and polyfluorobenzene-thiolates furnishing square-planar complexes [Ni(SR)₂(dippe)](R = C₆F₅2a, C₆F₄H 2b, C₆H₄F 2c or Ph 2d). These compounds reacted with CNBu^t and Na[BPh₄] in EtOH to yield the derivatives cis-[Ni(SR)(CNBu^t)(dippe)][BPh₄](R = C₆F₅3a, C₆F₄H 3b, C₆H₄F 3c or Ph 3d). No reaction takes place with CO under similar conditions. These compounds exhibit fluxional behaviour in solution. Compound 1 also reacted with sodium dialkyldithiocarbamates affording [Ni(S₂CNR₂)(dippe)]Br (R = Et 4a or Me 4b), which contain one bidentate dithiocarbamate ligand. However, the reaction with alkyl dithiocarbonates occurs with degradation, and the ultimate metal-containing product is the dithiocarbonate complex [Ni(S₂CO)(dippe)]5, the crystal structure of which has been determined. All the compounds have been characterized by IR and NMR spectroscopy and microanalysis.