New mixed metal chain complexes of platinum(II) with copper(II), cobalt(II), nickel(II), zinc(II), uranium(VI), and thorium(IV) having substituted phosphonito groups as bridging ligands

Complexes PtCl[OP(OMe)2][HOP(OMe)2]L (L = PEt3, PPh3) are acidic and the proton bonded to oxygen can be removed by titration with sodium methoxide or 1,5-diazabicyclo[4.3.0]non-5-ene. The resulting anionic compound will chelate to copper(II), cobalt(II), dioxouranium(VI), and thorium(IV) through the oxygens to give mixed metal compounds (PtCl[OP(OR)2]2L)/sub n/M (n = 2, R = Me, L = PEt3, M = Cu, UO2 and L = PPh3, M = Co; n = 2, R = Ph, L = PEt3, M = Cu; n = 4, R = Me, L = PPh3, M = Th). The complex PtCl[OP(OMe)2][F2BOP(OMe)2]PEt3 can be prepared by treating PtCl[OP(OMe)2][HOP(OMe)2]PEt3 with BF3 . Et2O. Mixed metal trimetallic compounds are also obtained by treating the compounds Pt[OP(OMe)2]2(L--L) with the appropriate metal salt (L--L = 1,2-bis(diphenylphosphino)ethane (dppe), o-phenylenebis(dimethylarsine)(diars)). Complexes [(Pt[OP(OMe)2]2(L--L))2M](ClO4)2 (M = Cu, Zn, L--L = dppe, diars; M = Ni, Co, L--L = dppe) have been prepared. Electronic spectra of the mixed metal complexes show a square-planar geometry about copper (II) and nickel(II) and a tetrahedral geometry about cobalt(II). The cobalt(II) complexes show unusually low extinction coefficients for the visible and near-infrared bands, although with Racah parameter B values in the 650--700-cm-1 range the explanation for the low extinction coefficients is likely distortion rather than highly ionic character about Co