Pentafluorophenyl gold complexes

Figure 2.3 Selected examples of (pentafluorophenyl)gold(lll) complexes with monodentate N-ligands.

The cyclic carbene complex shown in equation 3.4 was studied by X-ray diffraction [66], it shows a linear complex (angle C—Au—C 178.6(4)°) and the gold aryl bond distance is 1.993(10) A which is in accordance with such bonds in other known pentafluorophenyl complexes. The gold carbene carbon distance is 1.961(9) A, the dihedral angle between the planes formed by the two organic ligands is 5.35° and the shortest intermolecular Au—Au distance is 3.95 A. 

Neutral ylide, isocyanide and carbene pentafluorophenyl gold] 111) complexes with the general formulae trans-[Au]C6F5)X2]CH2PR3)[ ]PR3 = PPh3, PPh2Me, PPhMe2),... 

A different way to prepare pentafluorophenyl gold] 111) complexes is depicted by replacement of the halogen atom from the starting material as MCI or AgCl. Some examples are illustrated by the following equations (Equations 3.13-3.19) ... 

Coordination of pentafluorophenyl gold(III) to the two free N-donor atoms in 1,1 -bis(2-pyridylthio)ferrocene leads to the dinuclear complex [ Au(C6F5)3 2 Fc(Spy)2 ] structurally characterized [149]. 

Uson, R., Royo, P. and Laguna, A. (1974) Reactions of complexes of gold(I) with bis (pentafluorophenyl)thallium(III) halides. Journal of Organometallic Chemistry, 69(3), 361-365. 

Uson, R., Laguna, A., Vicente, J., Garcia, J., Bergareche, B. and Brun, P. (1978) Neutral isocyanide and carbene pentafluorophenyl complexes of gold(l) and gold(lll). Inorganica Chimica Acta, 28 (2), 237-243. 

Cronje, S., Raubenheimer, H.G., Spies, H.S.C., Esterhuysen, C., Schmidbaur, H., Schier, A. and Kruger, G.J. (2003) Synthesis and characterisation of N-coordinated pentafluorophenyl gold(I) thiazole-derived complexes and an unusual self-assembly to form a tetrameric gold(I) complex. Dalton Transactions, (14), 2859-2866. 

Uson, R., Laguna, A., Laguna, M., Fernandez, F., Jones, P.G. and Sheldrick, G.M. (1982) Tris(pentafluorophenyl)gold (III) complexes. Journal of the Chemical Society, Dalton Transactions, (10), 1971-1976. 

Uson, R., Lagrma, A., Laguna, M., Fernandez, E., Villacampa, M.D., Jones, P.G. and Sheldrick, G.M. (1983) Mono-, bi-, and trinuclear bis (diphenylphosphino)methanegold complexes. Crystal and molecular structures of [bis(diphenylphosphino) methane]bis(pentafluorophenyl)gold(lll) perchlorate and 1,2 2,3-di- X-[bis (diphenylphosphino) methane] -1,3-dichlorotrigold(l) chlorotris (pentafluorophenyl)aurate(lll). Journal of the Chemical Society, Dalton Transactions, (8), 1679-1685. 

Uson, R., Royo, P. and Lagrma, A. (1973) Two new ways for the synthesis of pentafluorophenyl-gold(III) complexes. Synthesis in Inorganic and Metal-Organic Chemistry, 3(3), 237-244. 

Vicente, J., Bermudez, M.D., Chicote, M.T. and Sanchez-Santano, M.J. (1989) Attempts to prepare mixed diarylgold(III) complexes containing a pentafluorophenyl group. Synthesis of [2- (dimethylamino) methyl phenyl-C 1N)-(pentafluorophenyl)gold(III) complexes. Journal of Organometallic Chemistry, 371 (1), 129-135. 

The first thing to point out is that the use of a pentafluorophenyl CgFs group with late transition metal confers on the complexes great stability, both thermodynamic and kinetic. This general fact, that is also true in gold chemistry, can be explained by different factors ... 

Unlike alkyl-gold bonds the Au—C bonds in pentafluorophenyl compounds are more resistant to cleavage by protic acids, giving more chemical integrity to the complexes. 

The pentafluorophenyl group imparts greater crystallinity to the complexes and as a result many complexes have been studied by X-ray crystallography. Although vith other metal centers C Fs-CaFs or CfiFs-CfiHs n-n stacking interactions are observed [21, 22], there are not many examples in gold chemistry and they have been sho vn very recently [23]. 

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