Ammine ligands, reaction with

This yellow, diamagnetic complex provides one of the few examples of metal hydrido compounds which contain only saturated ammine ligands. Osmiuin(v).—Further Os -arylimido-complexes have been synthesized via the reaction of phosphinimines with [OsOCl3(PPh3)2] ... 

Ammine ligands complexed to platinum(IV) will undergo condensation reactions with acetylacetone. Thus Pt(NH3) + and acetylacetone react rapidly to give the diimine complex (equation 332).1032... 

Figure 5-40. The first step in the reaction of cobalt(m) ammine complexes with hydroxide often involves deprotonation of an ammine ligand to give an amido species.

Intermolecular addition of carbon nucleophiles to the ri2-pyrrolium complexes has shown limited success because of the decreased reactivity of the iminium moiety coupled with the acidity (pKa 18-20) of the ammine ligands on the osmium, the latter of which prohibits the use of robust nucleophiles. Addition of cyanide ion to the l-methyl-2//-pyr-rolium complex 32 occurs to give the 2-cyano-substituted 3-pyrroline complex 75 as one diastereomer (Figure 15). In contrast, the 1-methyl-3//-pyrrolium species 28, which possesses an acidic C-3-proton in an anti orientation, results in a significant (-30%) amount of deprotonation in addition to the 2-pyrroline complex 78 under the same reaction conditions. Uncharacteristically, 78 is isolated as a 3 2 ratio of isomers, presumably via epimerization at C-2.17 Other potential nucleophiles such as the conjugate base of malononitrile, potassium acetoacetate, and the silyl ketene acetal 2-methoxy-l-methyl-2-(trimethylsiloxy)-l-propene either do not react or result in deprotonation under ambient conditions. 

The preparation of substituted pentacyanoferrate(II) ion complexes involves a series of ligand exchange reactions at the iron(II) metal center. Equations (4.1)-(4.3) outline the synthesis of amino acid (AA) metal complexes in aqueous solution. Starting from sodium nitroprusside ion, [Fe(CN)5(NO)]2, equation (4.1), the nitrosyl ligand, NO+, is replaced by an ammine moiety, NH3. The aquapentacyanoferrate(II) ion, [Fe(CN)5(H20)]3, is then generated in situ, equation (4.2), followed by reaction with an AA to yield the desired [Fe(CN)5(AA)](3+n) complex, equation (4.3). 

Proposed mechanism for reaction of a deprotonated ammine ligand with an adjacent coordinated phosphate monoester, leading to formation of a new chelated aminophosphate ligand. 

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