First example of ‘palladium‐nanoparticle’‐catalyzed selective alcoholysis of polyhydrosiloxane: a new approach to macromolecular grafting
2005; Wiley; Volume: 19; Issue: 4 Linguagem: Inglês
10.1002/aoc.867
ISSN1099-0739
AutoresBhanu P. S. Chauhan, Jitendra S. Rathore, Naim Glloxhani,
Tópico(s)Porphyrin and Phthalocyanine Chemistry
ResumoAbstract ‘Palladium‐polysiloxane’ nanocomposites were synthesized as stable and isolable powder by reduction of Pd(OAc) 2 with polymethylhydrosiloxane, which functions as a reducing agent and as a capping agent for the generation and stabilization of ‘palladium’‐nanoclusters. Redispersion of ‘palladium‐polysiloxane’ nanocomposite in common organic solvents, in the presence of polymethylhydrosiloxane, yielded catalytically active polysiloxane‐wrapped soluble ‘palladium’‐nanoclusters. Polysiloxane‐encapsulated ‘palladium’‐nanoclusters were used as recyclable catalyst for macromolecular grafting via alcoholysis of polyhydrosiloxane. Selective alcoholysis of polyhydrosiloxane took place in fair to excellent yields under moderate reaction conditions with a variety of alcohols (primary, secondary, tertiary/sterically bulky and functional alcohols). ‘ In situ ’ electron microscopy studies of the reaction mixtures in conjunction with controlled poisoning experiments revealed catalytic participation of ‘palladium’‐nanoclusters during substitution reactions. Copyright © 2005 John Wiley & Sons, Ltd.
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