Syntheses of Selenolato-Bridged Dinuclear Hydridoplatinum Complexes [Pt2H2(μ-SetBu)2(PPh3)2] and [Pt2H(SetBu)(μ-SetBu)2(PPh3)2]: Unusual Thermal Reaction of Hydrido(1,1-Dimethylethaneselenolato) Platinum Complex cis-[PtH(SetBu)(PPh3)2]

Polydentate chalcogen reagents for the facile preparation of Pd2 and Pd4 complexes

The silylated organochalcogen reagents 1,2-(Me3SiSCH2)2C6H4, and 1,2-(Me3SiSeCH2)2C6H4, were prepared from the corresponding organobromides and lithium trimethylsilanechalcogenolate Li[ESiMe3] (E = S, Se). They have been characterized by multinuclear NMR spectroscopy ((1)H, (13)C, (77)Se) and electrospray ionization mass spectrometry. and react under mild conditions with (1,3-bis(diphenylphosphino)propane)palladium(ii) chloride, [PdCl2(dppp)], to provide the dinuclear organochalcogenolate-bridged complexes [(dppp)2Pd2-μ-κ(2)S-{1,2-(SCH2)2C6H4}]X2, []X2 and [(dppp)2Pd2-μ-κ(2)Se-{1,2-(SeCH2)2C6H4}]X2, []X2 (X = Cl, Br) in good yield, respectively. Furthermore, the tetranuclear palladium complex [(dppp)4Pd4-μ-κ(4)S-{1,2,4,5-(SCH2)4C6H2}]X4, []X4 (X = Cl, Br) can be synthesized from the reaction of the tetrathiotetrasilane 1,2,4,5-(Me3SiSCH2)4C6H2, and [PdCl2(dppp)]. The structures of []X2, []X2 and []X4 were determined by single crystal X-ray diffraction methods. A variety of NMR experiments including two-dimensional homonuclear and heteronuclear correlated spectra were used to probe the solution behaviour of the dinuclear complexes in more detail. These complexes were further characterized by electrospray ionization (ESI) mass spectrometry, and for []X2 and []X2, UV-Vis absorption spectroscopy.

Platinum complexes of a borane-appended analogue of 1,1'-bis(diphenylphosphino)ferrocene: flexible borane coordination modes and in situ vinylborane formation

A bis(phosphine)borane ambiphilic ligand, [Fe(η(5) -C5 H4 PPh2 )(η(5) -C5 H4 PtBu{C6 H4 (BPh2 )-ortho})] (FcPPB), in which the borane occupies a terminal position, was prepared. Reaction of FcPPB with tris(norbornene)platinum(0) provided [Pt(FcPPB)] (1) in which the arylborane is η(3) BCC-coordinated. Subsequent reaction with CO and CNXyl (Xyl=2,6-dimethylphenyl) afforded [PtL(FcPPB)] {L=CO (2) and CNXyl (3)} featuring η(2) BC- and η(1) B-arylborane coordination modes, respectively. Reaction of 1 or 2 with H2 yielded [PtH(μ-H)(FcPPB)] in which the borane is bound to a hydride ligand on platinum. Addition of PhC2 H to [Pt(FcPPB)] afforded [Pt(C2 Ph)(μ-H)(FcPPB)] (5), which rapidly converted to [Pt(FcPPB')] (6; FcPPB'=[Fe(η(5) -C5 H4 PPh2 )(η(5) -C5 H4 PtBu{C6 H4 (BPh-CPh=CHPh-Z)-ortho}]) in which the newly formed vinylborane is η(3) BCC-coordinated. Unlike arylborane complex 1, vinylborane complex 6 does not react with CO, CNXyl, H2 or HC2 Ph at room temperature.