Synthesis and Reactivity of Heterotrinuclear Platinum Cyclometalated Complexes Containing Bridging Nitrido Ligands

The treatment of [M(L-OEt)(N)Cl-2] (L-OEt(-)=[Co(eta(5)-C5H5){P(O)(OEt)(2)}(3)](-)) with the Pt(II) bis(cyclometalated) complex [Pt(C N CBu)(DMSO)] (H2C N CBu=2,6-di(4-tert-butylphenyl)pyridine; DMSO=dimethylsulfoxide) afforded the heterotrinuclear nitrido complexes [LOEtCl2M(mu-N)Pt(C N CBu)] (M=Ru (1-Ru), Os (1-Os)). The Pt-N(nitrido) (1.821(5) angstrom) and Ru-N (1.673(5) angstrom) distances in1-Ruare consistent with the Ru=N=Pt bonding description. The Pt-N(nitrido) distance in1-Os(1.859(7) angstrom) is longer than that in1-Ru, suggesting the pi interaction between Pt(II) and Os equivalent to N is weaker than that for the Ru counterpart. Oxidation of1-Ruwith PhICl(2)afforded the Pt(IV) dichloride complex [LOEtCl2Ru(mu-N)Pt(C N CBu)Cl-2] (2) that has a longer Pt-N distance (1.893(3) angstrom) than that in1-Ru, indicating the weakening of the Pt-N(Ru) pi bonding upon oxidation of Pt(II) to Pt(IV). Treatment of [Pt(C N CBu)(DMSO)] with [nBu(4)N][Ru(N)Cl-4] in tetrahydrofuran (THF) afforded [nBu(4)N][(THF)Cl4Ru(mu-N)Pt(C N CBu)] (3), which reacted with K[N(Ph2PS)(2)] and K[N(iPr(2)PO)(2)] to yield [Cl{N(Ph2PS)2}(2)Ru(mu-N)Pt(C N CBu)] (4) and [nBu(4)N][Cl-3{N(iPr(2)PO)(2)}Ru(mu-N)Pt(C N CBu)] (5), respectively. The short Pt-N(nitrido) distances in3(1.816(5) angstrom) and4(1.809(2) angstrom) are indicative of Pt=N double bond character.