Ammine complexes synthesis

Kolis et al. reported the synthesis of some metal sulfide salts of homolep-tic lanthanide ammine complexes using supercritical ammonia as a reaction medium (Scheme 12) [49]. They proposed that these reactions proceed via a... 

Alternative methods for the synthesis of mononuclear Os(VI) nitrido complexes are the chemical or electrochemical oxidation of Os(II) or Os(III) ammine complexes (41-43) and the oxidation of Os(IV) complexes by organic azides (44). 

Sargeson and his coworkers have developed an area of cobalt(III) coordination chemistry which has enabled the synthesis of complicated multidentate ligands directly around the metal. The basis for all of this chemistry is the high stability of cobalt(III) ammine complexes towards dissociation. Consequently, a coordinated ammonia molecule can be deprotonated with base to produce a coordinated amine anion (or amide anion) which functions as a powerful nucleophile. Such a species can attack carbonyl groups, either in intramolecular or intermolecular processes. Similar reactions can be performed by coordinated primary or secondary amines after deprotonation. The resulting imines coordinated to cobalt(III) show unusually high stability towards hydrolysis, but are reactive towards carbon nucleophiles. While the cobalt(III) ion produces some iminium character, it occupies the normal site of protonation and is attached to the nitrogen atom by a kinetically inert bond, and thus resists hydrolysis. 

Until recently ammine complexes of osmium have been little studied compared with their ruthenium analogs. This appears to have been caused by the lack of suitable synthetic routes to them. The discovery of pentaammine(dini-trogen)osmium (II) opened convenient routes to pentaammines of osmium (III), and a convenient synthesis of hexaammineosmium(IIl)2 gave new routes to the previously unknown nitrosyls of osmium(II). Here are given the synthesis of [Os(NH3)s(N2)]l2 and its conversion to [Os(NH3)5l]l2 the synthesis of [Os(NH3)6]l3 and its conversion to [Os(NH3)5(NO)]X3 H20(X = Cl, Br, I) and the preparation of [OsX(NH3)4(NO)]2+(X = OH, Cl, Br, I) from [Os(NH3)5(NO)]3+. 

A classical example of photochemical synthesis of a metal ammine complex is the conversion of a stable nitro to unstable nitrito complex, reaction (16). 

Smirnov AV, Ilyushin MA, Tselinskii IV (2004) Synthesis of cobalt(ni) ammine complexes as explosives for safe priming charges. Russ J Appl Chem 77 794-796 Steckl AJ, Xu J, Mogul HC (1994) Crystallinity and photoluminescence in stain-etched porous Si. J Electrochem Soc 141 674-679... 

The iridium(III) complexes are broadly similar to the rhodium(III) ammines a selection of synthesis is shown in Figure 2.84. 

---