Dinuclear metal-sulfur complexes

As the dinuclear metal-sulfur complexes that can exhibit excellent ability to serve as the precursors to the tailored metal-sulfur clusters, those with the M2S4 cores are known to be used for synthesizing cubane-type and relating sulfido clusters. These include the reactions that start from the complexes having Mo( t-SH)2(jt-S)2Mo,38 M(p-S2)(p-S)2M (M = V,39 Mo40), Ru(p-S2)2Ru,41 and MS(p-S)2MS (M = Mo, W,42 Re,43 Ti44) cores, which are summarized in Figure 10. 

Oxidative-addition reactions have been widely studied with bridged dinuclear metal complexes [1,2,5, 32]. Earlier work with the ylides and sulfur bonded ligands... 

Doye s group [81] showed that a dinuclear titanium-sulfonamidate complex (Scheme 21), with a tetrahedral sulfur in the ligand backbone, can be used for intermo-lecular hydroaminoalkylation as well. This system gives mixtures of branched and linear products, although to date there has been no mechanistic rationale provided for the reduced regioselectivity of group 4 metal complexes in this transformation. There has been one report by Zi s group [44] that describes axially chiral bis(sulfonamidate) tantalum and niobium complexes for application as precatalysts for hydroamination and hydroaminoalkylation. Unfortunately, these complexes did not show any reactivity for either of these reactions. 

Wachter et al. reported the synthesis of polysulfido complexes of group 5 metals by the reaction of the corresponding trihydrides with elemental sulfur (Scheme 15). The reaction of Cp yNbHs with Ss gives the dinuclear poly-... 

Few examples have been reported of metals coordinated to six-membered boron-sulfur heterocycles. Ashe et al. prepared 4-methyl-l,4-thiaborin (SC4H4BMe) which forms a stable molybdenum tricarbonyl sandwich complex 144.158 jn g etjert s laboratory, the reaction of the diborolyl complex 33 (Section 3.01.3.2) with COS afforded the dinuclear complex 145 whose structure was determined crystallographically.36 Other products, not involving boron-sulfur heterocycles and hence outside the scope of this discussion, were obtained via the treatment of 33 with different sulfur reagents such as CS2.36... 

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