Silver l 11 Complexes

Recently, Lacour, Sauvage and coworkers were able to show that the association of chiral [CuL2] complexes (L=2-R-phen,6-R-bpy and2-iminopyridine) with TRISPHAT 8 leads to an NMR enantiodifferentiation, which allows the determination of the kinetics of racemization of the complexes (bpy=2,2 -bipyri-dine phen=l,10-phenanthroline) [119]. This type of application has recently been reported in conjunction with chiral sandwich-shaped trinuclear silver(l) complexes [122]. Several reports, independent from Lacour s group,have confirmed the efficiency of these chiral shift agents [123-127]. Finally, TRISPHAT can be used to determine the enantiomeric purity of (r] -arene)chromium complexes. These results broaden the field of application of 8 to chiral neutral, and not just cationic, species [114,128,129]. 

Catalano, V.J. and Horner, S.J. (2003) Luminescent gold(l) and silver(l) complexes of 2-(diphenylphosphino)-l-methylimidazole (dpim) Characterization of a three-coordinate Au(l)-Ag(l) dimer with a short metal-metal separation. Inorganic Chemistry, 42, 8430-8438. 

Table 58 Thermodynamic Data for the Formation of some Silver(l) Complexes with Potentially Bidentate N.S...

Crown ether 4 has been shown to be a source of unusual dinuclear silver(l) complexes <2002ICA(332)18>. In the crystal, the silver ions interact with the crown ether ligand at both the hard donor ethereal oxygens and soft benzene ring carbon atoms via intermolecular cation-Tt-interaction in -fashion, as depicted in Figure 6. The dimeric structure is further stabilized by the occurrence of intermolecular Tt-Tt-intcractions between facing benzo groups. 

The tridentate BoxCarb ligand was used to synthesise the corresponding carbene complexes of silver(I), rhodium(III) and palladium(II) [101]. Interestingly, the potentially tridentate BoxCarb ligand coordinates in a bidentate fashion only in the case of the silver(l) complex and it is the linker-free oxazoline ring that remains pendant. The coordination... 

The obtained amino functionalised imidazolium salts could be used to generate the corresponding palladium(ll) carbene complexes using the silver(l) complexes as carbene transfer agents. Application of these palladium(ll) complexes (predominantly in situ) in asymmetric allylic alkylation reactions between ( )-l,3-diphenylprop-3-enyl acetate and dimethyl malonate (a standard reaction for this catalytic process [145]) gave up to 80% ee,... 

Figure 3.67 Synthesis offuran functionalised imidazolium salts and their silver(l) complexes.

Figure 3.173 The silver(l) complex of a potential C,C,C pincer carbene ligand.

Figure 4.40 Proposed mechanism for the POP of (L)-lactide by a silver(l) complex of a carboxylic acid amide functionalised carbene.

Cesarotti, E., Araneo, S., Rimoldi, I., Tassi, S. Enantioseiective Mukaiyama aidoi and Sakurai aiiyiation reactions catalysed by silver(l) complexes with chiral atropisomeric chelating ligands. J. Mol. Catal. A Chemical 2003, 204-205, 221 -226. 

As an example, it was reported that the TfO salt of the tetracoordinated silver(l) complex with 2,2 -bipyridine-4,4 -disubstituted ligands 33 yielded a novel ionic liquid crystal displaying columnar mesomorphism [69]. The coordination and the ionic bonds drive the supramolecular assembly because the ligand is nonmesogenic or smectic, but when coordinated to the metal, it gives columnar mesomorphism... 

A survey of 301 interpenetrated structures in the CSD and ICSD was undertaken in 2004 which showed the distribution of structure types given in Figure 9.34. The 3D diamondoid net with its large adamantoid cavities proved to be by far the most common interpenetrated solid. For coordination polymers the highest degree of interpenetration is 10-fold and occurs for a silver(l) complex of... 

Gold(l)-alkynyls have also been employed as T] -metalloligands in the constmction of mixed-metal gold(l)-copper(l) and silver(l) complexes of the form [rj -(R3P)AuC=CC(=CH2)Me2Cu]PF6 (R = Ph, p-Tol) and... 

The mechanistic understanding is that a coordinated aldehyde undergoes enolization within the coordination sphere of the ruthenium catalyst. A subsequent oxidation of the metal upon interaction with the silver(l) complex provides a Ru(IV) catalyst state that is nucleophilicaUy attacked by fluoride. This step installs the carbon-fluorine bond and reduces the ruthenium catalyst back to oxidation state n. Displacement of the product by another substrate molecule closes the overall catalytic cycle. 

Sulfamates 175 were found to react with PhI(OAc)2, MgO, in the presence of rhodium catalysis, to provide oxathiazines 176 via C-H insertion (Equation 47) <2001JA6935>. This type of reaction can be catalyzed also by silver(l) complexes to give products 178 from substrates 177 (Equation 48) <2004AG(E)4210>. 

McNulty J, Keskar K, Vemula R (2011) The first well-defined silver(l)-complex-catalyzed cycloaddition of azides onto terminal alkynes at room temperature. Chem Eur J 17 14727-14730... 

Chiral Phosphine-Silver(l) Complex-Catalyzed Asymmetric Reactions... 

Fig. 2 Reaction sequence for excitation of the silver(l) complex of 1. Rate constants (in s" ) and/or efficiencies are given for each reaction.

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