Ammines of ruthenium

Chapter XII. Metal-Ammines of Ruthenium, Rhodium, and Palladium. ... 

PENTAAMMINE (NITROGEN)RUTHENIUM(II) SALTS AND OTHER AMMINES OF RUTHENIUM... 

Substitution reactions of ruthenium ammines. H. Taube, Comments Inorg. Chem., 1981, 1, 17-31... 

Reversible reactions. Consider the elementary reaction A + B P + Q with an equilibrium constant of unity. Such a situation pertains to certain reactions of ruthenium-ammine complexes.14 These authors give an integrated equation applicable when P and Q are absent initially ... 

All three metals of this group give rise to ammino-derivatives the compositions of which, however, differ considerably. The ammino-derivatives of ruthenium mostly contain a nitroso-group as well as ammonia the ammino-derivatives of rhodium salts closely resemble the cobalt -ammines and the ammino-derivatives of palladium salts correspond to the ammino-derivatives of platinum salts. 

These hydroxo-salts are all sulphur-yellow crystalline substances. The acid residues are hydrolysable and hence outside the co-ordination complex, and the aqueous solutions, unlike the hydroxo-salts of chromium-and cobalt-ammines, are neutral to litmus, a fact which Werner suggests is due to the smaller tendency of the hydroxo-radicle attached to ruthenium to combine with hydrogen ions. This tendency is much less than in the case of the ammines of cobalt and chromium, but that it still exists is indicated by the increased solubility of these hydroxo-compounds in water acidified with mineral acids, and from such solutions aquo-nitroso-tetrammino-ruthenium salts are obtained thus ... 

J. N. Armor, Studies in the Reactivity of Ruthenium Ammines, Ph.D. thesis, Standford University, 1970. 

Similarly Na N(SiMe3)2 can be used to deprotonate the ruthenium(I) ammine of Equation (6.7).512... 

In similar but more complicated processes, chelated a-diimines can be formed by reaction of ruthenium(III) and osmium(III) ammine complexes with biacetyl however, reduction of the metal also occurs (Scheme 49).220 A 0-diimine complex is obtained when acetylacetone undergoes reaction with hexaammineplatinum(TV) ions in basic solution (equation 39).220... 

Syntheses of the ammine complexes of ruthenium (III) have appeared in the literature, but the methods given here offer advantages in time and yield over the earlier procedures. 

The chemistry of ruthenium aqua complexes has been compared to the corresponding ammine species.1875... 

There are now a substantial number of nitrido complexes of osmium(VI) and osmium(IV) as well as the osmiamate ion [OsVII 03N]. In addition to the ammine and ethylenediamine complexes, much recent work has been carried out on the bipy, phen and terpy complexes, often in connection with research into the photodissociation of water. The nitrosyl chemistry of the element, though seemingly not as extensive as that of ruthenium, has received much attention, and there has been considerable work on the phosphine, arsine and stibine complexes. 

In 1854, Carl Ernst Claus (1796-1864), a professor of Chemistry at the University of Kazan and the discoverer of ruthenium (also known by the Russian name of Karl Karlovich Klaus), rejected the ammonium theory and proposed a return to Berzelius view of complexes as conjugated compounds. He compared the platinum-ammines with metal oxides, rather than with ammonium salts or ammonium hydroxide. He called the coordinated ammonia molecule passive, in contrast to the active, alkaline state in the ammonium salts, where it can easily be detected and replaced by other bases . 

Figure 4. Illustrative examples of the contrasting electronic absorption (a) and molecular quadratic NLO responses (b) of ruthenium ammine complexes and related purely organic pyridinium polyene chromophores [45]. In (b). the squares refer to the organic series, while the diamonds refer to the complex salts 21-24, the circles refer to the analogous series with trans pyridine (py) ligands, and the triangles refer to the pentaammine series...

Coe, B.J., Jones, L.A., Harris, J.A., Brunschwig, B.S., Asselberghs, I., Clays. K., Persoons. A. Highly unusual effects of --conjugation extension on the molecular linear and quadratic nonlinear optical properties of ruthenium(II) ammine complexes. J. Am. Chem. Soc. 125, 862-863 (2003)... 

A mechanistic study of the reaction of ruthenium ammine complexes with NO was reported almost four decades earlier. Although [Ru(NH3)6] is very inert, an acidic solution of this complex ion was observed to undergo a rapid reaction in the presence of NO to form [Ru(NH3)s(NO)]. [164] An electrophilic substitution process was invoked, with NO considered to function as an electrophile and the product proposed to be Ru -NO". The conclusion from a subsequent study was that a bond making mechanism operates for this... 

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