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The addition of [NBu4]Br or [NBu4][BH4] to solutions of [Pt4(μ-PPh2)4(C6F5)4(CO)2] (3) yields the complexes [NBu4]2 [Pt4(μ-PPh2)4(μ-X)2(C6F5)4] (X = Br, 4; H, 5) in which the two CO groups have been replaced by two anionic, bridging X ligands. The total valence electron counts are 64 and 60, respectively; thus, complex 4 does not require Pt-Pt bonds, while two metal-metal bonds are present in 5, as their NMR spectra confirm. Also, the NMR spectra indicate a nonsymmetrical "Pt(μ-PPh2)22Pt(μ-PPh2)(μ-X)Pt(μ-PPh2)(μ-X)Pt" disposition for 4 and 5. Treatment of 5 with HX (X = Cl, Br) yields the complexes [NBu4]2[Pt4(μ-PPh2)4(μ-H)2(C6F5)3X] (X = Cl, 6; Br, 7). These complexes react with [Ag(OClO3)PPh3] with displacement of the halide and formation of [NBu4][Pt4(μ-PPh2)4(μ-H)2(C6F5)3PPh3] (8). Complexes 6-8 maintain the same basic skeleton as 5, with two Pt-Pt bonds. Complex 4 is, however, an isomer of the symmetric [NBu4]2[{(C6F5)4Pt(μ-PPh2)2Pt(μ-Br)}2] (9), which has been prepared by a metathetical process from the well-known [NBu4]2[{(C6F5)2Pt(μ-PPh2)2Pt(μ-Cl)}2] (1). The comparison of the X-ray structures of 4 and 9 confirms the different disposition of the bridging ligands, and their main structural differences seem to be related to the size of Br- and its position in the skeleton. [ABSTRACT FROM AUTHOR]

The reactivity of the dinuclear platinum(III) derivative [(RF)2 PtIII(μ-PPh2)2PtIII(RF)2](Pt-Pt) (RF = C6F5) (1) toward OH-, N3-, and NCO- was studied. The coordination of these nucleophiles to a metal center evolves with reductive coupling or reductive elimination between a bridging diphenylphosphanido group and OH-, N3-, and NCO- or C6F5 groups and formation of P-O, P-N, or P-C bonds. The addition of OH- to 1 evolves with a reductive coupling with the incoming ligand, formation of a P-O bond, and the synthesis of [NBu4]2[(RF)2PtII(μ-OPPh2)(μ-PPh2)PtII(RF)2] (3). The addition of N3- takes place through two ways: (a) formation of the P-N bond and reductive elimination of PPh2N3 yielding [NBu4]2[(RF) 2PtII(μ-N3)(μ-PPh2)PtII(RF)2] (4a) and (b) formation of the P-C bond and reductive coupling with one of the C6F5 groups yielding [NBu4][(RF)2PtII(μ-N3)(μ-PPh2)PtII(RF)(PPh2RF)] (4b). Analogous behavior was shown in the addition of NCO- to 1 which afforded [NBu4]²[(RF)2PtII(μ-NCO)(μ-PPh2)PtII(RF)2] (5a) and [NBu4][(RF)2PtII(μ-NCO)(μ-PPh2)PtII(RF)(PPh2RF)] (5b). In the reaction of the trinuclear complex [(RF)2PtIII(μ-PPh2)2PtIII(μ-PPh2)2PtII(RF)2](PtIII-PtIII) (2) with OH- or N3-, the coordination of the nucleophile takes place selectively at the central platinum(III) center, and the PPh2/OH- or PPh2/N3- reductive coupling yields the trinuclear [NBu4]2[(RF)2PtII(μ-Ph2PO)(μ-PPh2)PtII(μ-PPh2)2PtII(RF)2] (6) and [NBu4][(RF)2Pt¹(μ3-Ph2PNPPh2)(μ-PPh2)Pt²(μ-PPh2)Pt³(RF)2](Pt²-Pt³) (7). Complex 7 is fluxional in solution, and an equilibrium consisting of Pt-Pt bond migration was ascertained by 31P EXSY experiments. [ABSTRACT FROM AUTHOR]

Highlights: [•] Di- and trinuclear phosphanido synthons to tetra- and hexanuclear platinum complexes. [•] Polynuclear complexes with only P and N (or O) donors bridging the platinum centres. [•] The first X-ray characterized “Pt(μ-1,1-N3)Pt” and “Pt(μ-C2O4-κ2 O,O′:κ2 O″,O‴)Pt” systems. [•] Tetra and hexanuclear complexes with the Pt centres in a linear arrangement. [ABSTRACT FROM AUTHOR]

The rational synthesis of dinudear asymmetric phosphanido derivatives of palladium and platinum(II), [NBu4][(Rp)2M(μ-PPh2)2M'(k2,N,C-C13H8N)] (Rp = C6F5; M = M' = Pt, 1; M = Pt, M' = Pd, 2; M = Pd, M' = Pt, 3; M = M' = Pd, 4), is described. Addition of I2, to 1-4 gives complexes [(RF),MIII(μ-PPh2)(μ-I)PdII{PPh2(C13H5N)}] (M = M' = Pt, 6; M = Pt, M' = Pd, 7; M = M' = Pd, 8; M = Pd, M' = Pt 10) which contain the aminophosphane PPh2(C13H5N) ligand formed through a Ph2P/CN reductive coupling on the mixed valence M(II)-M'(IV) [NBu4][(Rp)2MIIμ-PPh2);M'IV(k2,N,C- C13H8N)I2] complexes, which were identified for MII = Pd, M'IV = Pt (9), and isolated for MII = Pt, M'IV = Pt (5). Compl ex 5 showed an unusual dynamic behavior consisting in the exchange of two phenyl groups bonded to different P atoms, as well as a "through space" spin--spin coupling between ortho-F atoms of the pentafluorophenyl rings. [ABSTRACT FROM AUTHOR]