Recent developments on carbon-carbon cross-coupling reactions using rare-earth metals-derived coordination polymers as efficient and selective Pd catalytic systems

Most recent progress on the Suzuki-Miyaura, Heck and Sonogashira cross-coupling reactions, induced by heterobimetallic Pd-Ln coordination polymers as heterogeneous catalysts has been accurately reviewed. Physical-chemical characterization of the Pd-Ln composite materials by adequate physical methods revealed the distinct structure and configuration of the two- and three-dimensional frameworks. The important contribution of the coordination polymers as catalyst supports to finely modulating the catalytic activity and chemoselectivity has been considered. Published results illustrate the high activity and chemoselectivity of Pd-Ln coordination polymers in cross-coupling reactions, excellent catalyst recoverability and recyclability as well as low catalyst loading or metal leaching, under optimized reaction conditions. The particular effect of the solvent, base, aryl halide or related reagents in governing the main steps of the Pd catalytic cycle has been particularly outlined. In addition, the well-established cooperative effect of the lanthanides with palladium, with emphasis on the synergism between different metals in heterobimetallic catalytic systems, has been highlighted.

Plasmonic Ag nanoparticles decorated g-C_(3)N_(4)for enhanced visible-light driven photocatalytic degradation and H_(2)production

The plasmonic Ag nanoparticles(NPs)loaded g-C_(3)N_(4)photocatalysts(Ag/C_(3)N_(4))were successfully prepared via a conventional procedure.The fully characterized Ag/C_(3)N_(4)photocatalysts exhibited excellent stability and greatly enhanced visible light-driven photocatalytic performance both in the degradation of methyl orange(MO)and H_(2)evolution from water splitting.The 1.0 wt%Ag/C_(3)N_(4)allowed the highest reaction rate of 0.0294 min^(−1)to be obtained in the MO degradation,which is about 2.3 times higher than the reaction rate of g-C_(3)N_(4)alone of 0.0129 min^(−1).Furthermore,the optimum H_(2)evolution and the k value attained 20μmol and 1.573 h^(−1),respectively,after 12 h of visible light irradiation.The surface plasmon resonance effect of Ag NPs and the charge transfer between the two components of the photocatalyst,strongly promote generation of photoinduced charge carriers while suppressing their recombination.These factors are held responsible for the enhanced visible light photocatalytic performance of Ag/C_(3)N_(4).Our methodology will provide guidance for the design and synthesis of plasmon-enhanced visible light photocatalysts derived from Ag NPs and g-C_(3)N_(4)and their applications in environmental remediation and green energy development.