Gold derivatives

The compound 70 has also been reported showing the ambident character (both C- and N-coordination) of the cyano-stabilized ylide as ligand. The authors have also transposed their work concerning the keto-bis-ylide and palladium, with the synthesis of the C-bonded complex 71 or the new cycloplatinated or-thometallated compound 72. The latter by various treatments allows one to obtain other ylidic cationic complexes of platinum such as 73. A C,C,C-terdentate coordination of the keto bis-ylide, already observed with the palladium is also obtained from the reaction of 73 with gold derivatives. 

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 polynuclear derivatives [ AuAg(C6F5)2L J [129, 130] were prepared by reacting the gold derivatives NBu4[Au(C6Fs)2] with Ag[C104], the polymeric complex... 

Bardaji, M Laguna, A. and Laguna, M. (1995) Phosphoniodithioformate gold derivatives. Synthesis of tricationic gold... 

Tiekrnk, E.R.T. (2002) Gold derivatives for the treatment of cancer. Critical Revieivs in Oncology/Hematology, 42, 225—248. 

It is interesting to note the influence of the counteranions on the thermal behavior. Irrespective of the isocyanide used, all the nitrate gold derivatives show low thermal stability and undergo extensive decomposition at relatively low temperatures (only the low melting trialkoxyphenyl derivative shows liquid crystal behavior). In contrast. 

For substituted 5-alkynylamines, gold derivatives are the most efficient catalysts (Eq. 4.72) [283]. 

Au-B bonds are also present in metal clusters with intersticial or peripheral boron atoms. An example is the cluster [Fe4(CO)12BH(AuPPh3)2], which was prepared by reaction of [AuCl(PPh3)] with the carbonyl iron dihydride. With the oxonium salt the reaction proceeds to the trinuclear gold derivative [Fe4(CO)12B(AuPPh3)3] (357).2063-2070 The ruthenium analogues and complexes with other ligands have been also synthesized as, for example, (358).2071-2079... 

Fig 11. Approximate Bragg resolution for the first exposure of each of eight crystals (inch one gold derivative) from H. marismortui 508 subunits that were investigated at SSRL beam-line 7-1 (Stanford University, Ca., USA) at cryotemperature... 

Figure 2.38 Different patterns in gold derivatives with stoichiometries [Au2L2(p-P P)].

This type of interatomic contact is sometimes found in halogen or chalcogen gold derivatives, and the vast majority of the examples described in the literature are of the type X- X, that is, they contain the same element in both extremes of the interaction. Of these, the most frequent are I- -I or S- -S interactions, although there are other non-metal- non-metal contacts, such as F- F, Br- -Br, Se- -Se or - - . 

The addition of water and methanol to terminal alkynes has also been studied by Laguna et al. by pentafluorophenyl and mesityl gold derivatives. Both acidic and non-acidic conditions led to high activity, even in the presence of as little as 0.5 mol% of catalyst. The use of pentafluorophenyl compounds allowed them to obtain additional spectroscopic information in the stoichiometric reaction of the complex [Au (C6F5)2C1]2 and phenylacetylene, which showed that gold(III) was the active species in the catalytic process. The reaction followed the Markovnikov rule, as shown in the proposed mechanism (Scheme 8.13), delivering the corresponding ketones or diacetal products [96]. 

The three complexes are luminescent in the solid state at room temperature and at 77 K or in frozen solutions of dichloromethane or acetone. The optical behavior in frozen solution is similar for the three complexes and also similar to that of the precursor gold derivatives [AuR(tht)], but not in the solid state. The differences in this state are attributed to the different number and types of metal-metal interactions present in each complex. In agreement with this assumption,... 

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