Ligands nonbridging, substitution

The second open triangular iron system in Table 1 (type 9) is formed from a trithiocarbonate by cleavage of a C=S double bond. A bridging carbene ligand and a sulfur atom a thereto donate four electrons to the metal framework. With the unsaturated derivative of the thione, S= CSCH=CH, a corresponding desulfurization with [Fe2(CO)9] produces a nonbridging carbene ligand in a carbonyl-substituted derivative of [Fe3(CO)9S2] (compare with type 8) (25). 

Studies on Pt(II)-catalyzed substitution reactions of Pt(IV) show striking nonbridging-ligand effects, e.g., the rate law for substitution of labeled chloride in cis-and trans-fPtCNHjj Cl j takes place by the rate law ... 

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