Reactivity, and Catalytic Activity

Keywords Clusters Clusters, metal Clusters, supported metal Clusters, ligands bonded to Clusters reactivities and catalytic activities... 

It is the purpose of this article to discuss whether or not there are any differences between the chemical reactivity of a polymer-metal complex and that of the corresponding monomeric complex. Although various extensive investigations on polymer-metal complexes have been reported, most of these complexes are too complicated to be discussed quantitatively due to the nonuniformity of their structure. These compounds include not only complexes of macromolecules but also the structurally labile metal complex . Before detailed information can be obtained about the properties of polymer-metal complexes, and especially about the reactivity and catalytic activity of polymer-metal complexes, their structure must be elucidated. A polymer-metal complex having a uniform structure may be defined as follows ... 

IV. Oxides and Halides with the Rock Salt Structure Surface Structure, Reactivity, and Catalytic Activity... 

Organometallic derivatives of polyoxometalates are perfectly characterized at the molecular level and in turn provide models for the grafting of an organometallic catalyst on an oxide surface, especially in the case of the supported derivatives. Beyond, they also display their own reactivity and catalytic activity.Some synergy between the organometallic and oxide parts has been reported in the literature, as well as bifunctional activity. The mobility of organometallic fragments at an oxide surface could also be reproduced on a polyanion. 

Blom B, Tan G, Enthaler S, Inoue S, EppingJD, Driess M. Bis-N-heterocychc carbene (NHC) stabilized ti -arene iron(0) complexes synthesis, structure, reactivity, and catalytic activity.. Tm Chem Soc. 2013 135 18108-18120. 

Barret and Hill have extensively studied the reactivity and catalytic activity of NHC-supported Group 2 amido complexes. Similar to several reports with the alkali metals, tricoordinate NHC-alkaline earth metal complexes 58 could be formed directly from the corresponding conjugate acid by addition of a metal amide salt (Scheme 5.8). Whereas carbene-Li complexes were found to be excellent carbene transfer reagents, 58 could function as a stable carbene equivalent. Indeed, in the presence of Lewis base donors such as triphenylphosphine oxide or protic substrates such as 2-methoxyethylamine, liberation of the free carbene was observed by and NMR. While the authors did not attempt to isolate this free carbene or investigate any additional reactivity, they claimed that the carbene was dissociated under catalyt-ically relevant conditions. 

Metal-oxide clusters such as polyoxometallates offer attractive prospects as catalysts, since these oxide clusters are robust, their structures can be systematically varied, sites of stable coordinative unsaturation can be created, and catalytically active metal centers can be incorporated at the cluster surfaces or within the cluster framework. Structures approximated as Cs2H2(PVMoi] 04q) are selective methacrolein oxidation catalysts. Further research is recommended it should include synthesis and development of methods for stable molecular dispersion on supports and systematic investigation of structure, reactivity, and catalytic activity. 

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