Chalcogenolate clusters

FIGURE 65 Common structural types of lanthanide chalcogenolate and chalcogenide clusters with nuclearity ranging from six to eight (redrawn after Li et al., 2006a). 

Towards Transition Metal Clusters by Reaction of Simple Metal Carbonyls with Chalcogenides and Chalcogenolates... 

Substitution reactions involving silylated chalcogen reagents represent a powerful approach in metal-group-XVI cluster synthesis.Compounds such as E(TMS)2 and RE-TMS react readily with metal salts to form metal chalcogenide or chalcogenolate bonds (Equations (13)-(15)). The driving force for the reaction is the thermodynamically favorable formation of an X—Si bond and elimination of X-TMS (where X = halide, OAc, etc.). 

In addition to the synthetic approaches described above, a number of alternative routes to polynuclear metal chalcogenide or chalcogenolate complexes have been described. Organometallic complexes will reduce elemental chalcogen, often resulting in the formation of clusters (e.g., Equation (22)). Many other approaches involve the use of chalcogen reagents other than those described in the previous sections. A selection of these is summarized in Equations (22)-(25) below ... 

The use of silylated chalcogen reagents in the synthesis of chalcogen-bridged metal clusters has produced a remarkable number of complexes with a variety of structural types. The nuclearities and structures of these complexes can be highly dependent on the reaction conditions, the steric demands of the ancillary and/or chalcogenolate ligands, as well as the ratio M E. Complexes... 

---