Peng Wang,Huan Liu,Yong-Qi Li,Xiao-Li Zhao,Yong Lu,Ye Liu
A series of ionic phosphonium-based aminophosphines L1–L3 were prepared and fully characterized, in each of which the involved bifunctional moieties of the phosphine fragment and Lewis acidic phosphonium were linked together by stable chemical bonds and bridged by one N-atom. The molecular structure of the L2-ligated Rh-complex (Rh-L2) indicated that such bifunctionalities were well retained without incompatibility problems. Investigations on co-catalysis over L1–L3 showed that L3 exhibited the best sequential catalysis for both hydroformylation and acetalization. The phosphine fragment in L3 was responsible for hydroformylation together with the Rh-complex and the phosphonium acted as the Lewis acidic catalyst in charge of acetalization. The L3–Rh(acac)(CO)2 system also exhibited good generality to hydroformylation–acetalization of a wide range of olefins in different alcohols.
Xuerui Cao,Guangwei Cao,Mei Li,Xinli Zhu,Jinyu Han,Qingfeng Ge,Hua Wang
Graphical Novel Au x Cu 2 O electrocatalysts were synthesized via the galvanic replacement reaction between Cu 2 O nanocubes and HAuCl 4 solution, and the pre-reduction by linear voltammetry (LSV). The Au 0.02 Cu 2 O pre-reduced by LSV significantly boosted C 2 H 4 selectivity in CO 2 electrocatalytic reduction, which were 5 and 2 times higher than those of bare Cu 2 O and Au 0.02 Cu 2 O pre-reduced by chronoamperometry at high potential, respectively. Electrochemical reduction of carbon dioxide to fuels has been recognized as a perspective way to address the environmental and energy issues. Herein, the novel Au decorated Cu 2 O electrocatalysts were synthesized via the galvanic replacement reaction and the successive pre-reduction by linear voltammetry (LSV) method. In contrast to Cu 2 O, CO formation became dominant over HCOOH and H 2 on Au x Cu 2 O, and a remarkably enhanced selectivity of C 2 H 4 was obtained beyond −1.1 V vs. RHE. Among them, Au 0.02 Cu 2 O exhibited the highest Faraday efficiency (FE) of C 2 H 4 of 24.4 % at −1.3 V vs. RHE, which was as high as 2∼2.5 and 5 times of those on other two Au x Cu 2 O and bare Cu 2 O, respectively. Meanwhile, it is demonstrated that the optimal ratio of Au/Cu was essential for effective sequential catalysis between Au and Cu 2 O to enhance C−C coupling. Furthermore, the effect of copper states resulting from different pre-reduction methods on the selectivity of C 2 H 4 was explored. A half decrease of C 2 H 4 FE was observed on HPR-Au 0.02 Cu 2 O (high potential reduced) relative to the LSV reduced Au 0.02 Cu 2 O, which was ascribed to the different content of Cu 0 and residual Cu + in two catalysts. Our results demonstrate an effective approach to construct Cu 2 O based bimetallic catalysts for ethylene formation from CO 2 .
Distinctively different metabolism between tumor cells and normal cells endows tumor tissues unique microenvironment. In this regard, we have successfully prepared a sequential catalytic platform based on Au/Pt star for tumor theragnostic. The multifunctional probes consisted of a gold/platinum star-shaped core (Au/Pt star) conjugated with a GSH-sensitive disulfide bond (S–S), a targeting ligand (rHSA-FA), a near-infrared fluorophore (IR780) and glucose oxidase (GO x ). When systemically administered in a xenografted murine model, the probes specifically targeted the tumor sites. As the disulfide linker was cleaved by intracellular GSH, the IR780 molecules could be released for photo-thermal therapy & photodynamic therapy (PTT&PDT) and imaging. Subsequently, the Pt nanolayer of the Au/Pt star and the GO x formed a sequential catalytic system: GO x effectively catalyzed intracellular glucose by consuming oxygen to generate H 2 O 2 and enhance the local acidity, and the Pt layer exhibited peroxidase-like property to catalyze H 2 O 2 producing toxic ·OH for tumor oxidative damage. Here we demonstrated that our probes simultaneously possessed a GSH-sensitive release, real-time imaging ability, and synergetic cancer starving-like therapy/enzyme oxidative therapy/PTT/PDT features, which provides a potential strategy for effective tumor theragnostic.
危险品化学品经营许可证（带存储）