The synthesis and characterization of Ni, Pd and Pt maleonitriledithiolate complexes:: X-ray crystal structures of the isomorphous Ni, Pd and Pt (Ph2PCH2CH2PPh2)M(maleonitriledithiolate) congeners

The synthesis of a series of maleonitriledithiolate complexes of nickel, palladium and platinum phosphines having the formulae (dppe)M(mnt) and (Ph3P)(2)M(mnt) (where dppe = Ph2PCH2CH2PPh2, mnt = 1,2-dicyanoethene-1,2-dithiolate and M =Ni, Pd or Pt) from the reaction of Na-2(mnt) and the appropriate (phosphine) MCl2 is reported. These complexes were characterized by a combination of mass spectrometry, IR, UV-Visible and H-1, C-13 and P-31 NMR spectroscopy. In addition, characterization of the title complexes by single crystal X-ray diffraction of all three congeners revealed them to be isomorphous. Analysis of the diffraction data reveals that the metal centers are all square planar, that the planar mnt ligands are tilted slightly away from the metal square planes, and that the mnt ligand is best described as a dithiolate rather than a dithione. (C) 1998 Elsevier Science S.A. All rights reserved.