New Multi-Walled Carbon Nanotubes Functionalized with Dendrimer Stabilized Palladium Nanoparticles Catalyst for C-C Cross Coupling Reactions
Two types of multi-walled carbon nanotubes are (MWCNTs) functionalized with dendrimer/palladium nanoparticle catalysts viz., MWCNTs-poly(propylene imine) generation 2 (G2)-PdNPs (MWCNTs-PPI(G2)-PdNPs) and MWCNTs-poly(propylene imine) generation 3 (G3)-PdNPs (MWCNTs-PPI(G3)-PdNPs) were prepared. The newly developed catalysts were characterized by the spectroscopic/microscopic techniques. The catalytic activity of these catalysts were investigated by performing C-C cross coupling reactions viz., (i) Suzuki-Miyaura, (ii) Heck and (iii) Sonogashira as model reactions. The formation of product in each reaction was identified by thin layer chromatographic (TLC) technique (2:8 percentages of ethyl acetate and hexane) and then purified by column chromatography.The resulting products were characterized by 1H and 13CNMR spectroscopy and the percentage of yield was calculated by gravimetrical method. The study of reusability of the superior catalyst viz.,MWCNT-PPI(G3)-PdNPs was examined so as to know the stability of the catalyst for the same reactions.