Silver-Metal Bonded Compounds

Silver-Metal Bonded Compounds. Stable salts of formula Me4N[Ag M(CO)3-Cp 2] (M = Mo or W) have been isolated from aqueous diglyme solutions of Na[M(CO)3Cp] and AgN03. Since their i.r. spectra are similar to those of the known Hg[M(CO)3Cp]2 compounds, the complex anions are believed to be non-centrosymmetric, with the first reported cases of linear M— Ag—M bonding. 

Silver(ii).—New fluorides of this unusual silver oxidation state have been described, including M AgM F6 (M = K, Rb, or Cs M = Tl, In, Ga, Al, Sc, Fe, or Co), and Ag[MFg] (M = Rh, Pd, or Pt). Some of these complexes show remarkable colours and complicated magnetic behaviour. 

Mixed-ligand complexes of Ag have been prepared for the first time by displacing neutral terdentate dipicH2 (= pyridine 2,6-dicarboxylic acid) from [Ag(dipic)(dipicH2)],4H20  

A comparative study has appeared of the X-ray photoelectron spectra of a range of Ag and Ag N-donor complexes. The Ag 3 3/2 and 3 5/2 binding energies show little dependence on the formal oxidation state, but peak widths are usually considerably broader ca. 0.8 eV) for the paramagnetic Ag species. This increased width may be caused partly by the presence of multiplet splittings . In the course of these studies the new orange-brown isoquinoline-1-carboxylato-complex [AgL2] was also isolated  

Sflver(III).—To date the only reported Ag complexes are guanidine derivatives. However, oxidation of the known Ag octaethylporphinato-species with Fe( 104)3 in CHCl3-MeOH solution has yielded the corresponding Ag metalloporphyrin. The crystalline product is diamagnetic, as expected for a compound. In both this complex and previous guanidine species the extraordinary stabilization of the central d ion arises from the square-planar co-ordination to four N atoms. 

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This class of compounds showing explosive instability deals with heavy metals bonded to elements other than nitrogen and contains the separately treated groups GOLD COMPOUNDS LEAD SALTS OF NITRO COMPOUNDS LITHIUM PERALKYLURANATES MERCURY COMPOUNDS METAL ACETYLIDES METAL FULMINATES METAL OXALATES PLATINUM COMPOUNDS PRECIOUS METAL DERIVATIVES SILVER COMPOUNDS... 

The Shannon-Prewitt ionic radii (r+ + r ) are based on the most ionic compounds, the fluorides and oxides for the radii of the metal cations, and the alkali hahdes for the radii of the anions of the remaining halides. The shortening of silver halide bond lengths is attributahle to polarization and covalency. 

Summary of Metal-Metal Bond Lengths for High-Nuclearity Gold-Silver Heteronuclear Cluster Compounds... 

The correct answer is (B). NH3 has the weakest intermolecular forces of the other molecules. Diamond exists in a covalent network bond, sodium acetate is an ionic compound, and glycerine contains several C O and O H bonds (which allow hydrogen bonding). Silver has metallic bonds while ammonia, NH3, is only held together by fairly weak hydrogen bonds (the N-H bond is not very polar). 

Reactions of silver(i) or sodium cyanoacetates with Cp2TiCl2 afford the bis(cyanoacetato) complex Cp2Ti(02CCH2CN)2. The molecular structure shows O-unidentate carboxylate groups the cyano-nitrogen atom is not bonded to the metal. This compound can alternatively be prepared from Cp2TiMe2 and cyanoacetic acid.1581... 

Propiolic Acid, HC=C.COOH, is a liquid with a pungent odor resembling that of acetic acid. After freezing it melts at 9°. It can be distilled without decomposition only under diminished pressure. It is interesting on account of the fact that its reactions show clearly its relation to acetylene. It forms as an acid, well characterized salts, and as a triple bonded compound, metallic derivatives, which result from the replacement of the hydrogen atom joined to carbon by silver or copper. When the acid is treated with an ammoniacal solution of silver nitrate a colorless, crystalline salt is formed, which soon turns yellow and explodes when struck. Propiolic acid may be prepared by the action of carbon dioxide on the sodium derivative of acetylene —... 

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