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Gold clusters: synthesis and characterization of [Au8(PPh3)7(CNR)]2+, [Au9(PPh36(CNR2]3+ and [Au11(PPH37(CNR)2O]2+ and their reactivity towards amines. The crystal structure of [Au11(PPh3)7(CN-i-Pr)2I](PF6)2

1986; Elsevier BV; Volume: 307; Issue: 3 Linguagem: Inglês

10.1016/s0022-328x(00)98962-9

1872-8561

W. Bos, R. P. F. Kanters, C.J. Van Halen, W. P. Bosman, H. Behm, J.M.M. Smits, Paul T. Beurskens, J. J. Bour, L. H. Pignolet,

Organometallic Complex Synthesis and Catalysis

In the reactions of [Au8(PPh3)7]2+, [Au8(PPh3)8]2+ and [Au9(PPh3)8]3+ with RNC (R = isopropyl and t-butyl) in dichloromethane [Au8(PPh3)7CNR]2+ is initially, and is then converted into [Au9(PPh3)6(CNR)2]3+ via various intermediates. [Au9(PPh3)6(CNR)2]3+ reacts with I− at low temperature (−78°C) in methanol to yield [Au11(PPh3)7(CNR)2I]2+, but when the reaction is carried out at room temperature Au11 (PPh3)6(CNR)I3 is formed. The cluster compounds have been characterised by elemental analysis, 31P{1H} NMR, conductivity measurements, IR and 197Au Mössbauer spectroscopy. The reactions of the clusters with amines to form carbene clusters are very slow, and the reasons for this are considered. The structure of [Au11C134H112IN2P7](PF6 was determined by X-ray diffraction. Mr = 3796.39 cubic, space group 143d, a 37.955(12) Å, V 54677.2 Å3, Z = 16, Dc = 2.21 Mg m−3, Mo-Kα radiation (graphite crystal monochromator, λ 0.71069 Å), μ(Mo-Kα) 125.2 cm−1, F(000) = 33510.3, T 293 K. Final conventional R-factor = 0.048, Rw = 0.062 ofr 1867 unique reflections and 198 variables. The Au-skeleton is the same as in Au11(PPh3)8I3 having C3v symmetry with one central and 10 peripheral Au atoms.