Di and trimetallic Pt-II, Pt-IV complexes containing dimethylphosphonate groups as bridging ligands.

The complexes [Pt{(P(O)(OMe)(2))(2)H}(2)] and [PtCl(PPh3){(P(O) (OMe)(2))(2 )H}] react with Tl(acac) in chloroform or with KOH in methanol solution to yield the trinuclear and binuclear complexes, [Pt{mu-P)O) (OMe)(2)}(4)M-2] and [PtCl(PPh3){mu-P(O) (OMe)(2)}(2)M] (M = Tl, K), respectively. These der ivatives react with (PtMe3)(2)SO4. H2O or (OMe(3)Ptl}(4)] with formation of the solvated complexes [Pt{mu-P(O))OMe)(2)}(4){PtMe3(MeOH)}(2)] and [PtCl( PPh3){mu-P(O) (OMe)(2)}(2)(PtMe3(MeOH)}]. Addition of donor ligands displac es the coordinated methanal to afford the corresponding adducts [Pt{mu-P(O) (OMe)(2)}(4)(PtMe3L}(2)] (L= py, 3,5-Me(2)py, P(p-MeOPh)(3)} and [PtCl(PPh 3){mu-P(O) (OMe)(2)}(2){PtMe3L}] (L. = py, PPh3). The complexes are charact erized by elemental analysis, and IR and NMR spectroscopy.