Transition metal substituted polyoxometalates TMSP

Figure 5.1 General structure of the Keggin-type (a) and sandwich-type (b) transition metal substituted polyoxometalates (TMSPs) used in catalysis W (green) O (red) heteroatom X (yellow) transition metal M (pink). See insert for color representation of the figure.)...

Polyoxometalates are able to act as ligands for different redox-active transition metals (M ) such as iron, manganese, cobalt and ruthenium or d metals (such as zirconium, hafnium, titanium). The coordination of a heterometal by a polyoxometalate framework takes place either through the superficial coordination of a metal cation by electrostatic interaction, or by incorporation of the transition metal within the POM structure resulting in the formation of transition metals substituted polyoxometalates (TMSPs), which generally exhibit a higher stability. 

In the previous section, transition-metal-substituted polyoxometalates (TMSPs) supported on Si02 [61, 62] have been mentioned. TMSPs have been also tested when immobilized on Ti02- For instance, the H5PW10V2O40 supported on Ti02 was active in the photocatalytic decomposition of dimethyl sulphide (DMS) in gas-... 

Goals and five limitations in conjunction with the development of selective catalytic homogeneous oxidation systems are evaluated. Systems are presented that address several of the problems or goals. One involves oxidation of alkenes by hypochlorite catalyzed by oxidatively resistant d-electron-transition-metal-substituted (TMSP) complexes. A second involves oxidation of alkenes by H2O2 catalyzed by specific TMSP complexes, and a third addresses functionalization of redox active polyoxometalate complexes with organic groups. 

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