Au and Au-containing bimetallic nanoparticles are promising catalysts for the green synthesis of fine chemicals. Here, we used a Au6Pd/resin catalyst for the aerobic C-C cross-coupling of primary and secondary alcohol...Au and Au-containing bimetallic nanoparticles are promising catalysts for the green synthesis of fine chemicals. Here, we used a Au6Pd/resin catalyst for the aerobic C-C cross-coupling of primary and secondary alcohols to produce higher ketones under mild conditions. This is of importance to the construction of a C-C bond. Various substrates were used in the reaction system, and moderate to good yields were obtained. The catalysts can be reused at least five times without decrease of yield. The control experiment and XAFS characterization results showed that hydrogen au- to-transfer occurred on metallic Pd sites even under oxidative conditions. On alloying with Au, the Pd sites became resistant to oxidation and readily abstracted the β-H of the alcohols and transferred the hydride to the C=C bond in the reaction intermediate to give the saturated product.展开更多
The paper briefly addresses DLR' s ( German Aerospace Center) expertise in space robotics by handof corresponding milestone projects including systems on the International Space Station ISS. It then discussesthe k...The paper briefly addresses DLR' s ( German Aerospace Center) expertise in space robotics by handof corresponding milestone projects including systems on the International Space Station ISS. It then discussesthe key technologies needed for the development of an artificial "robonaut" generation with mechatronic ultra-light weight arms and multifingered hands. The third arm generation is nearly finished now, approaching thelimits of what is technologically achievable today with respect to light-weight and power losses. In a similar wayDLR' s second generation of artificial 4-fingered hands was a big step towards higher reliability, manipulabilityand overall performance.展开更多
基金supported by the National Natural Science Foundation of China (21373206, 21202163, 21303194, 21476227, 21503219)~~
文摘Au and Au-containing bimetallic nanoparticles are promising catalysts for the green synthesis of fine chemicals. Here, we used a Au6Pd/resin catalyst for the aerobic C-C cross-coupling of primary and secondary alcohols to produce higher ketones under mild conditions. This is of importance to the construction of a C-C bond. Various substrates were used in the reaction system, and moderate to good yields were obtained. The catalysts can be reused at least five times without decrease of yield. The control experiment and XAFS characterization results showed that hydrogen au- to-transfer occurred on metallic Pd sites even under oxidative conditions. On alloying with Au, the Pd sites became resistant to oxidation and readily abstracted the β-H of the alcohols and transferred the hydride to the C=C bond in the reaction intermediate to give the saturated product.
文摘The paper briefly addresses DLR' s ( German Aerospace Center) expertise in space robotics by handof corresponding milestone projects including systems on the International Space Station ISS. It then discussesthe key technologies needed for the development of an artificial "robonaut" generation with mechatronic ultra-light weight arms and multifingered hands. The third arm generation is nearly finished now, approaching thelimits of what is technologically achievable today with respect to light-weight and power losses. In a similar wayDLR' s second generation of artificial 4-fingered hands was a big step towards higher reliability, manipulabilityand overall performance.
