Silver carboxylate complexes

Hayama et al.132 discussed the catalytic effects of silver ion-polyacrylic add systems toward the hydrolyses of 2,4-dinitrophenylvinylacetate 84 (DNPVA) by using the weak nudeophilicity of carboxylic groups and the change-transfer interactions between olefinie esters and silver ions133Metal complexes of basic polyelectrolytes are also stimulating as esterase models. Hatano etal. 34, 13S) reported that some copper(II)-poly-L-lysine complexes were active for the hydrolyses of amino acid esters, such as D- and L-phenylalanine methyl ester 85 (PAM). They... 

When Br2 reacts with aryl R, at low temperature in inert solvents, it is possible to isolate a complex containing both Br2 and the silver carboxylate see Bryce-Smith, D. Isaacs, N.S. Tumi, S.O. Chem. Lett., 1984, 1471. 

Silver(I) complexes with oxygen donor ligands have been prepared with three different types of ligands /3-diketonates, carboxylates, and crown ethers. 

In a joint study by Schmidbaur and Raubenheimer, several phosphine carboxylates and sulfonates of gold and silver were tested as catalysts for the hydration of nonactive alkynes [99]. While the gold complexes showed high activity for these reactions, analogous silver (I) complexes were not active in them. This different behavior was due to the fact that gold cations are weaker acceptors for their ligands and counterions than silver (I) cations (Figure 8.3). 

Limited structural information is available for silver(I) carboxylates, despite their extensive use as catalysts in the manufacture of urethane polymers. This is in part due to their frequent insoluble and light-sensitive nature making chemical characterization of the complexes difficult. Dimeric structures have been reported for the perfluorobutyrate249 and trifluoroacetate complexes.250 In each case two-fold symmetry was crystallographically imposed. The Ag—O bond lengths were 223-224 pm, and in the more accurate determination of the trifluoroacetate, the Ag—Ag separation was found to be 297 pm. A dimeric structure was also found for the silver(I) complex of 3-hydroxy-4-phenyl-2,2,3-trimethylhexane carboxylate.251 In the asymmetric crystal unit the Ag---Ag separations were 277.8 and 283.4 pm. 

Complex ions of the type Ag(02CR)J and Ag2(02CR)+ have been proposed to exist in solution, based on measurements of solubility in water and in mixed solvents. Some thermodynamic data for silver carboxylates are given in Table 35.253,254... 

Peroxydisulfate oxidations have also been used to prepare a variety of pyridine mono- and di-carboxylic add silver(II) complexes.496 All these compounds were orange-red in colour and sparingly soluble to insoluble in most solvents, including water. 

The oxidative effects of silver(II) complexes of pyridine carboxylates have been studied for a variety of substrates. With ar-amino acids, a rapid reaction occurred at 70 °C in aqueous solution with bis(pyridyl-2-carboxylato)silver(II). 4 The product was the next lower homologous aldehyde and yields were generally greater than 80%. Other substrates included primary and secondary amines, alcohols, monosaccharide derivatives, alkenes, arylalkanes and arylalkanols.90 Only minor differences were detected in efficiencies when 2-, 3- or 4-mono-, or 2,3-di-carboxylates were used as the oxidant. 

Reaction of [PdCl2(diene)] with silver carboxylates yields complexes [Pd2(/u -... 

Several cyanodithioformates are mentioned in ref. 1. The coordination chemistry of monothio-carboxylates deals almost exclusively with thioacetates and thiobenzoates. Structures of several monothiobenzoates are based on IR data.42 Those, however, of the copper(I) and silver(I) complexes are doubtful. They are probably polymeric and of the same structural class as the mono- and di-thiocarbamates43-45... 

A test for aldehydes. The Tollens reagent is a silver-ammonia complex Ag(NH3)2 OH]. Tollens reagent oxidizes an aldehyde to a carboxylate salt and deposits a silver mirror on the inside of a glass container, (p. 862)... 

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

Liao et al. also synthesised an imidazolium salt carrying two carboxylic acid amide functionalities and generated its silver carbene complex. It is distinguished by absolute linearity of the C-Ag-Cl vector and rather short Ag-C and Ag-Cl bond lengths. 

Silver carboxylate compounds are fight-sensitive and generally insoluble in most solvents, making it difficult for their structural characterization. In contrast, the zwitteri-onic betaine ligands R3N+(CH2) C02 form stable silver complexes that are soluble in water and ethanol, and a variety of discrete dimers or polymeric chain/network stractures constracted by the linkage of dimeric subunits have been obtained. ... 

Carboxylate complexes are often synthesized by refluxing the acid with the metal salts (such as carbonate, sulfate, oxide, etc.), or by reaction of the sodium or silver salt of the acid with the metal halide. Insertion of CO2 into a-bonded organotransition metal species has also been used to generate carboxylate complexes, as has exchange reactions with metal alkoxides (see Section 3.3). 

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