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 CNBut and Na[BPh4] in EtOH to yield the derivatives cis-[Ni(SR)(CNBut)(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.