Platinum catalysts dendrimer polymers

The robustness and excellent turnover numbers of platinum complexes with terminal alkynes have made it the catalyst of choice for the synthesis of polymers and other macromolecular architechtures. Alkyne hydrosilylation with platinum has also served as a key element in the synthesis of dendrimers. Sequential reaction of an alkyne with HSiMeCl2 and lithiated phenylacetylene afforded the branching unit of a dendrimer synthesis which has been used to afford a large variety of structures at high generation.44,4411 441 ... 

Dendrimer-encapstdated catalysts are another area of active research for polymer-supported catalysts. The nanoparticles are stabilized by the dendrimers preventing precipitation and a omeration. Bimetallic nanoparticles with encapsulated metals (dendrimer-encapsulated catalyst DEC) from commercially available fourth-generation PAMAM dendrimers and palladium and platinum metal salts were prepared via reduction by Crooks and co-workers [34], following previous work in this area [35], The simultaneous incorporation of Pt and Pd reflects the concentrations in solution. The bimetallic DECs are more active than the physical mixture of single-metal DEC [35, 36] in the case of the hydrogenahon of allyl alcohol in water, with a maximum TOP of 230 h compared to TOP = 190 h obtained for monometallic palladium nanoparticles (platinum TOP = 50 h ). 

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