Gold I Complexes

Au is also found in KigTl2oAu3, which contains [TI9AU2], [Tin] and Au . 

Two-coordinate complexes may be generally be obtained with any type of ligand able to coordinate to soft metal centers. These complexes may be neutral, positive or negative, and are linear, with bond angles approaching 180°. Thiolates (such as cysteine and thiomalate), thioethers (such as methionine and dimethylsulfide), selenols, phosphines, cyanide and alkyl groups (especially 

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Propylene oxide is also produced in Hquid-phase homogeneous oxidation reactions using various molybdenum-containing catalysts (209,210), cuprous oxide (211), rhenium compounds (212), or an organomonovalent gold(I) complex (213). Whereas gas-phase oxidation of propylene on silver catalysts results primarily in propylene oxide, water, and carbon dioxide as products, the Hquid-phase oxidation of propylene results in an array of oxidation products, such as propylene oxide, acrolein, propylene glycol, acetone, acetaldehyde, and others. 

Gold (I) complexes of bidentate phosphines and arsines like... 

AuCl3(tht) [129], AuX3[S(benzyl)2)2] (X = Cl, Br) [130] and AuC13 (thian-threne). Various dithiocarbamates and dithiolene complexes have been made, some by oxidation of gold(I) complexes (Figure 4.26). 

Perhalogenoaryls are more stable than the unsubstituted phenyls [176] and can be synthesized conveniently by oxidation of gold(I) complexes (demonstrating the stability of the Au-C bond). The initial product of oxidation addition seems to be the frans-isomer, which generally rearranges to the m-form ... 

Sodium borohydride reductions of gold(I) complexes give Au clusters at RT if sodium borohydride in ethanol is dropped slowly into a suspension of the Au(I) complex in the same solvent. The immediate coloring of the reaction mixture (mostly red), even after only a few drops of the borohydride have been added, indicates fast formation of Au clusters. In view of the complicated composition of these compounds the fast formation is surprising. The use of H2 and CO with HjO as reducing agents in the synthesis of gold clusters has been described (see Table 1, Method A, 8.2.2.2). 

A related dinuclear species 77, recently described, constitutes the first dinuclear gold(I) complex with heterobridged phosphor-1,1 -dithiolato moieties and bis(ylide) bridging ligands [ 102]. It is obtained by reaction between [ AuS2PPh2] and the diylide gold complex 74 (R=Me). No intermolecular Au-Au interaction is observed in 77 but the oxidative addition of chlorine to the product leads to a new complex 78 in which a single bond is formed between the two Au(II) centers (Scheme 26). 

The differences observed in the chemistry of these dinuclear gold(I) amidinate complexes compared with dinuclear gold(I) complexes with sulfur and carbon ligands may be understood by examining their respective highest occupied molecular orbital (HOMO)s and lowest unoccupied molecular orbital (LUMO)s of the species. 

Gold(I) ylides are oxidized in 0.1 M [Bu4N]BF4/THFat low potentials of +0.11 and + 0.23 V vs. Ag/AgCl (quasi-reversible). The dinuclear amidinate oxidizes under the same conditions at + 1.24 V vs. Ag/AgCl (reversible). These large differences in chemical character of the dinuclear gold(I) complexes appear to explain the widely different behavior of these compounds and especially toward the reaction with mercury cyanide. 

Reacting the amidinate salt, K[4-MePh-form], with the dinuclear gold(I) complex, [Au2(2,6-Me2Ph-form)2], in a 1 1 stoichiometry in THF forms the dinuclear-tetra-nuclear complex [Au2(2,6-Me2Ph-form)2][Au4(4-MePh-form)4]-2THF, Figure 1.24, with one tetranuclear and one dinuclear molecule in the same unit cell. Adjusting the reaction ratio to 2 1 formed the tetranuclear complex [Au4(4-MePh-form)4j. 

Rawashdeh-Omary, M.A., Omary, M.A., Fackler, J.P. Jr, Galassi, R., Pietroni, B.R. and Burini, A. (2001) Chemistry and optoelectronic properties of stacked supramolecular entities of trinuclear Gold(I) complexes sandwiching small organic acids. Journal of the American Chemical Society, 123, 9689. 

Sladek, A., Hofreiter, S., Paul, M. and Schmidbaur, H. (1995) Sodium tetraphenylborate as a phenylating agent for gold(I) complexes. Journal... 

Forward, J.M., Fackler, J.P. and Staples, R.J. (1995) Synthesis and structural characterization of the luminescent Gold(I) Complex [(MeTPAJjAulJIj. Use of NaBPha as a phenyl transfer reagent to form [(MeTPA)AuPh](BPh4) and (TPA) AuPh. Organometallics, 14, 4194—4198. 

Au "=0 species are postulated, inter alia, as active intermediates in the oxidation of alkanes with hydrogen peroxide catalyzed by gold(III) and gold(I) complexes [115]. The reaction sequence is proposed in Scheme 2.8. 

The reaction of the trimethyl tritiophosphite and triphenyl tritiophosphite with the gold derivative [Au(C6F5)(tht)] leads to the gold(I) complexes [57] shown in Figure 3.6. The crystal structure of the trimethyl tritiophosphite gold (I) complex was studied by X-ray diffraction and two different polymorphs were discovered. 

The reaction of the gold(I) complex [Au(C6F5)(tht)j with the water soluble phosphine l,3,5-triaza-7-phosphaadamantane (PTA) gives the complex Au(C6F5) PTA] [28]. 

The gold(I) complex [Au(C6F5)(tht)] has been used as starting material to synthesize numerous anionic Au(I) pentafluorophenyl derivatives as shown in Table 3.3. 

The reaction of the anionic gold(I) complex PPN[Au(C6F5)Cl] with [MeSi Me2SiN (p-tol) 3SnLi(OEt2)] leads to formation of an anionic complex with a Sn—An bond, shown in Equation 3.8, whose P H NMR spectrum shows a singlet at 47.5 ppm [81]. 

The most general method of preparing pentafluorophenylgold(III) derivatives is oxidative addition with the appropriate oxidant to the gold(I) complex. The choice of... 

Mixed triaryl gold(III) derivatives [Au(C6F5)R 2(tht)j ]169] (R = 2,3,4,6-C6p4H and 2,4,6-C6F3Fl2) have also been prepared by oxidative addition of [T1R 2C1]2 to the gold(I) complex [Au(C6F5)tht]. 

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