Coordinated chloramine

It seems safe to say that coordination will generally decrease the reactivity of donor atoms in the first row of the periodic table through steric effects. With some reactions the extent of this steric hindrance may be small. Ammonia can be transformed into chloramines when coordinated (34), and aromatic acid chlorides coordinated to A1C13 or TiCl4 may be esterified even when the functional group is a hindered one, as in mesitylene carbonyl chloride (47). These last reactions may proceed through a very reactive carbonium ion, whose existence is rendered possible by the polarization of the ligand which it suffers as a result of coordination. 

The same complex reacts with chloramine T to give a complex in which a nitrogen has been attached to the coordinated sulfur. These authors concluded that the sulfur atom of the original complex displays the reactivity typical of an organic sulfide. They also reported that the sulfur atom in the corresponding complex of cobalt (III) could be oxidized to the sulfone without disrupting the complex ... 

The compound containing coordinated chloramine is inclined to undergo a violent decomposition, so it should be prepared only in small quantities. A number of other reactions of this same type was demonstrated, including... 

Here, there is no evidence that masking interferes in any way with these reactions. When the complexes of palladium (II) were examined for a similar reactivity, no complexes containing coordinated chloramines could be isolated (43, 44)- The reaction of ammines of platinum (IV) with bromine can be used to introduce bromoamine in the coordination sphere, but the products are somewhat less stable than those obtained with chlorine. The general nature of the processes is similar. One example of a bromination reaction established by Kukushkin is ... 

The photochemical reactivity of [Rh NH3)5(N3)] " has proven especially interesting, for HCl solutions of the azidopentaammine ion undergo a ligand-centered reaction, releasing Nj gas, and generating the chloramine complex (equation 139). Minor products include [Rh(NH3)j] , [Rh(NH3)j(NH20H)] + and [Rh H3)5(H20)] +, and the ratio of products depends on the solution conditions and wavelength of irradiation. A coordinated nitrene mechanism, similar to that proposed for the thermal decomposition of Ru and azides was proposed, and is... 

Acetals are very labile toward aqueous acids, whereas the thioacetals are remarkably stable because of the softness of the sulfur atoms. Hydrolytic cleavage of the latter class of compounds almost invariably involves coordination with soft or borderline acceptors such as Hg(II) (1-3), Tl(III) (4), Ag(I) (5, 6), Cu(II) (7), R (8-11), Hal (12), and NH (13). Chloramine T (14) may be considered as a nitrene complex, hence a soft Lewis acid. 

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