55.   Lane, E. M.; Chapp, T. W.; Hughes, R. P.; Glueck, D. S.; Feland, B. C.; Bernard, G. M.; Wasylishen, R. E.; Rheingold, A. L. Inorg. Chem. 2010, 49, 3950–3957. Synthesis of Gold Phosphido Complexes Derived from Bis(secondary) Phosphines. Structure of Tetrameric [Au(MesP(CH₂)₃PMes)Au]₄.

Abstract

Treatment of 2 equiv of Au(THT)Cl (THT = tetrahydrothiophene) with the bis(secondary) phosphines HP(R)~PH(R) (linker ~ = (CH₂)₃, R = Mes = 2,4,6-Me₃C₆H₂ (1), R = Is = 2,4,6-(i-Pr)₃C₆H₂ (2), R = Ph (4); ~ = (CH₂)₂, R = Is (3); HP(R)~PH(R) = 1,1'-(h5-C₂H₄PHPh)₂Fe (5)), gave the dinuclear complexes (AuCl)₂(µ-HP(R)~PH(R)) (6-10). Dehydrohalogenation with aqueous ammonia gave the phosphido complexes [(Au)₂(µ-P(R)~P(R))]_n (11-15). Ferrocenyl- and phenylphosphido derivatives 15 and 14 were insoluble; the latter was characterized by solid-state ³¹P NMR spectroscopy. Isitylphosphido complexes 12 and 13 gave rise to broad, ill-defined NMR spectra. However, mesitylphosphido complex 11 was formed as a single product, which was characterized by multinuclear solution NMR spectroscopy, solid-state ³¹P NMR spectroscopy, and elemental analyses. Mass spectrometry suggested that this material contained eight gold atoms (n = 4). A structure proposed on the basis of the ¹H NMR spectra, containing a distorted cube of phosphorus atoms, was confirmed by X-ray crystallographic structure determination. NMR spectroscopy, including measurement of the hydrodynamic radius of 11 by ¹H NMR DOSY, suggested that this structure was maintained in solution. Density functional theory (DFT) structural calculations on 11 were also in good agreement with the solid-state structure.