Synthesis and characterization of homo- and hetero-nuclear mixed thiolate phosphine complexes with Ni^II, Pd^II, and Pt^II. Crystal and molecular structure of bis[μ-(3-dimethylamino-1-propanethiolato)]-bis{[1,2-bis(diphenylphosphino)- ethane]nickel(II)} tetraphenylborate

The following families of complexes have been prepared and characterized: [M{S(CH2)3NHMe2}2-(dppe)] [BPh4]2, dppe = Ph2PCH2CH2PPh2, M = Ni, Pd, or Pt; [M{S(CH2)3NMe2}2(dppe)], M = Pd or Pt; [(dppe)M{μ-S(CH2)3NMe2} 2M′(dppe)] [BPh4]2 (M = M′ = Ni, Pd, or Pt; M = Ni, M′ = Pd; M = Ni, M′ = Pt; M = Pd, M′ = Pt); and [Ni{Pt[μ-S(CH2)3NMe2] 2(dppe)}2][BPh4]2. Infrared spectra indicate that within each family the complexes have the same structure. Crystals of the homonuclear nickel dimer are triclinic, space group P1, with a = 14.346(1), b = 14.037(1), c = 13.207(1) Å, α = 105.79(1), β = 90.81(1), and γ = 113.06(1)°. The crystal structure consists of centrosymmetric binuclear thiolate-bridged cations and anions, well separated. The corresponding homonuclear complexes of PdII and PtII are isomorphous. The co-ordination of the metal atoms in the trinuclear complex [(dppe)Pt(μ-SR)2Ni(μ-SR)2Pt(dppe)]2+ [R = (CH2)3NMe2], has been deduced from 31P-{1H} n.m.r. data. In solution the platinum mononuclear complexes and the nickel dimeric species are the most stable.