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991.
Xiaoyang Chen Dannan Zheng Linye Jiang Zhiguo Wang Xinyu Duan Dong Cui Shuang Liu Yuan Zhang Xiaomin Yu Jingyan Ge Jian Xu 《Angewandte Chemie (International ed. in English)》2023,62(23):e202218140
Chiral sulfones are recurrent motifs in pharmaceuticals and bioactive molecules. Although chemical methods have been developed to afford α- or β- chiral sulfones, these protocols rely heavily on the pre-synthesis of structurally complicated starting materials and chiral metal complexes. Herein, we described a photoenzymatic approach for the radical-mediated stereoselective hydrosulfonylation. Engineered variants of ene reductases provide efficient biocatalysts for this transformation, enabling to achieve a series of β-chiral sulfonyl compounds with high yields (up to 92 %) and excellent e.r. values (up to 99 : 1). 相似文献
992.
Guanghui Feng Dr. Shibin Wang Prof. Shenggang Li Ruipeng Ge Dr. Xuefei Feng Prof. Junwei Zhang Dr. Yanfang Song Dr. Xiao Dong Jiazhou Zhang Prof. Gaofeng Zeng Prof. Qiang Zhang Prof. Guijun Ma Dr. Yi-De Chuang Prof. Xixiang Zhang Prof. Jinghua Guo Prof. Yuhan Sun Prof. Wei Wei Prof. Wei Chen 《Angewandte Chemie (International ed. in English)》2023,62(15):e202218664
Using sunlight to produce valuable chemicals and fuels from carbon dioxide (CO2), i.e., artificial photosynthesis (AP) is a promising strategy to achieve solar energy storage and a negative carbon cycle. However, selective synthesis of C2 compounds with a high CO2 conversion rate remains challenging for current AP technologies. We performed CO2 photoelectroreduction over a graphene/silicon carbide (SiC) catalyst under simulated solar irradiation with ethanol (C2H5OH) selectivity of>99 % and a CO2 conversion rate of up to 17.1 mmol gcat−1 h−1 with sustained performance. Experimental and theoretical investigations indicated an optimal interfacial layer to facilitate the transfer of photogenerated electrons from the SiC substrate to the few-layer graphene overlayer, which also favored an efficient CO2 to C2H5OH conversion pathway. 相似文献
993.
Yi Wan Dr. Jianghua He Dr. Yuetao Zhang 《Angewandte Chemie (International ed. in English)》2023,62(8):e202218248
Rapid access to sequence-controlled multi-block copolymers (multi-BCPs) remains as a challenging task in the polymer synthesis. Here we employ a Lewis pair (LP) composed of organophosphorus superbase and bulky organoaluminum to effectively copolymerize the mixture of methacrylate, cyclic acrylate, and two acrylates, into well-defined di-, tri-, tetra- and even a hepta-BCP in one-pot one-step manner. The combined livingness, dual-initiation and CSC feature of Lewis pair polymerization enable us to achieve not only a trihexaconta-BCP with the highest record in 8 steps by using four-component monomer mixture as building blocks, but also the arbitrarily-regulated monomer sequence in multi-BCP, simply by changing the composition and adding order of the monomer mixtures, thus demonstrating the powerful capability of our strategy in improving the efficiency and enriching the composition of multi-BCP synthesis. 相似文献
994.
Dr. Jiawei Zhang Dr. Daisuke Ishikawa Dr. Michael M. Koza Prof. Dr. Eiji Nishibori Dr. Lirong Song Dr. Alfred Q. R. Baron Prof. Dr. Bo B. Iversen 《Angewandte Chemie (International ed. in English)》2023,62(13):e202218458
Loosely bonded (“rattling”) atoms with s2 lone pair electrons are usually associated with strong anharmonicity and unexpectedly low thermal conductivity, yet their detailed correlation remains largely unknown. Here we resolve this correlation in thermoelectric InTe by combining chemical bonding analysis, inelastic X-ray and neutron scattering, and first principles phonon calculations. We successfully probe soft low-lying transverse phonons dominated by large In1+ z-axis motions, and their giant anharmonicity. We show that the highly anharmonic phonons arise from the dynamic lone pair expression with unstable occupied antibonding states induced by the covalency between delocalized In1+ 5s2 lone pair electrons and Te 5p states. This work pinpoints the microscopic origin of strong anharmonicity driven by rattling atoms with stereochemical lone pair activity, important for designing efficient materials for thermoelectric energy conversion. 相似文献
995.
Dr. Peng Zhang Qian-Cheng Luo Dr. Zhenhua Zhu Wanrong He Nan Song Junting Lv Xuning Wang Prof. Quan-Guo Zhai Prof. Yan-Zhen Zheng Prof. Jinkui Tang 《Angewandte Chemie (International ed. in English)》2023,62(12):e202218540
The syntheses and magnetic properties of organometallic heterometallic compounds [K(THF)6]{CoI[(μ3-HAN)RE2Cp*4]2} ( 1-RE ) and [K(Crypt)]2{CoI[(μ3-HAN)RE2Cp*4]2} ( 2-RE ) containing hexaazatrinaphthylene radicals (HAN⋅3−) and four rare earth (RE) ions are reported. 1-RE shows isolable species with ligand-based mixed valency as revealed by cyclic voltammetry (CV) thus leading to the isolation of 2-RE via one-electron chemical reduction. Strong electronic communication in mixed-valency supports stronger overall ferromagnetic behaviors in 2-RE than 1-RE containing Gd and Dy ions. Ac magnetic susceptibility data reveal 1-Dy and 2-Dy both exhibit slow magnetic relaxation. Importantly, larger coercive field was observed in the hysteresis of 2-Dy at 2.0 K, indicating the enhanced SMM behavior compared with 1-Dy . Ligand-based mixed-valency strategy has been used for the first time to improve the magnetic coupling in lanthanide (Ln) SMMs, thus opening up new ways to construct strongly coupled Ln-SMMs. 相似文献
996.
Dr. Pengwei Li Linfang Yan Qingli Cao Prof. Chao Liang He Zhu Sihui Peng Yongpeng Yang Yuncai Liang Rudai Zhao Prof. Shuangquan Zang Prof. Yiqiang Zhang Prof. Yanlin Song 《Angewandte Chemie (International ed. in English)》2023,62(13):e202217910
Low-dimensional Ruddlesden-Popper (LDRP) perovskites still suffer from inferior carrier transport properties. Here, we demonstrate that efficient exciton dissociation and charge transfer can be achieved in LDRP perovskite by introducing γ-aminobutyric acid (GABA) as a spacer. The hydrogen bonding links adjacent spacing sheets in (GABA)2MA3Pb4I13 (MA=CH3NH3+), leading to the charges localized in the van der Waals gap, thereby constructing “charged-bridge” for charge transfer through the spacing region. Additionally, the polarized GABA weakens dielectric confinement, decreasing the (GABA)2MA3Pb4I13 exciton binding energy as low as ≈73 meV. Benefiting from these merits, the resultant GABA-based solar cell yields a champion power conversion efficiency (PCE) of 18.73 % with enhanced carrier transport properties. Furthermore, the unencapsulated device maintains 92.8 % of its initial PCE under continuous illumination after 1000 h and only lost 3 % of its initial PCE under 65 °C for 500 h. 相似文献
997.
Shibing Zheng Dongjie Shi Tianjiang Sun Letian Zhang Weijia Zhang Yixin Li Zhenbo Guo Zhanliang Tao Jun Chen 《Angewandte Chemie (International ed. in English)》2023,62(9):e202217710
High-capacity small organic materials are plagued by their high solubility. Here we proposed constructing hydrogen bond networks (HBN) via intermolecular hydrogen bonds to suppress the solubility of active material. The illustrated 2, 7- diamino-4, 5, 9, 10-tetraone (PTO-NH2) molecule with intermolecular hydrogen (H) bond between O in −C=O and H in −NH2, which make PTO-NH2 presents transverse two-dimensional extension and longitudinal π–π stacking structure. In situ Fourier transform infrared spectroscopy (FTIR) has tracked the reversible evolution of H-bonds, further confirming the existence of HBN structure can stabilize the intermediate 2-electron reaction state. Therefore, PTO-NH2 with HBN structure has higher active site utilization (95 %), better cycle stability and rate performance. This study uncovers the H-bond effect and evolution during the electrochemical process and provides a strategy for materials design. 相似文献
998.
Zhiguo Sun Huijuan Zhang Linlin Cao Xiaokang Liu Dan Wu Xinyi Shen Xue Zhang Zihang Chen Sen Ru Xiangyu Zhu Zhiyuan Xia Qiquan Luo Faqiang Xu Prof. Tao Yao 《Angewandte Chemie (International ed. in English)》2023,62(13):e202217719
The construction and understanding of synergy in well-defined dual-atom active sites is an available avenue to promote multistep tandem catalytic reactions. Herein, we construct a dual-hetero-atom catalyst that comprises adjacent Cu-N4 and Se-C3 active sites for efficient oxygen reduction reaction (ORR) activity. Operando X-ray absorption spectroscopy coupled with theoretical calculations provide in-depth insights into this dual-atom synergy mechanism for ORR under realistic device operation conditions. The heteroatom Se modulator can efficiently polarize the charge distribution around symmetrical Cu-N4 moieties, and serve as synergistic site to facilitate the second oxygen reduction step simultaneously, in which the key OOH*-(Cu1-N4) transforms to O*-(Se1-C2) intermediate on the dual-atom sites. Therefore, this designed catalyst achieves satisfied alkaline ORR activity with a half-wave potential of 0.905 V vs. RHE and a maximum power density of 206.5 mW cm−2 in Zn-air battery. 相似文献
999.
Mingxia Guo Long Fang Linlin Zhang Mingzhu Li Meiyu Cong Xiping Guan Chuanwei Shi ChunLei Gu Xia Liu Yong Wang Xin Ding 《Angewandte Chemie (International ed. in English)》2023,62(13):e202217635
Atomically dispersed Fe was designed on TiO2 and explored as a Janus electrocatalyst for both nitrogen oxidation reaction (NOR) and nitrogen reduction reaction (NRR) in a two-electrode system. Pulsed electrochemical catalysis (PE) was firstly involved to inhibit the competitive hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Excitingly, an unanticipated yield of 7055.81 μmol h−1 g−1cat. and 12 868.33 μmol h−1 g−1cat. were obtained for NOR and NRR at 3.5 V, respectively, 44.94 times and 7.8 times increase in FE than the conventional constant voltage electrocatalytic method. Experiments and density functional theory (DFT) calculations revealed that the single-atom Fe could stabilize the oxygen vacancy, lower the energy barrier for the vital rupture of N≡N, and result in enhanced N2 fixation performance. More importantly, PE could effectively enhance the N2 supply by reducing competitive O2 and H2 agglomeration, inhibit the electrocatalytic by-product formation for longstanding *OOH and *H intermediates, and promote the non-electrocatalytic process of N2 activation. 相似文献
1000.
Chanjuan Zhang Dr. Philipp Gotico Dr. Regis Guillot Dr. Diana Dragoe Dr. Winfried Leibl Dr. Zakaria Halime Prof. Ally Aukauloo 《Angewandte Chemie (International ed. in English)》2023,62(8):e202300926
At the core of carbon monoxide dehydrogenase (CODH) active site two metal ions together with hydrogen bonding scheme from amino acids orchestrate the interconversion between CO2 and CO. We have designed a molecular catalyst implementing a bimetallic iron complex with an embarked second coordination sphere with multi-point hydrogen-bonding interactions. We found that, when immobilized on carbon paper electrode, the dinuclear catalyst enhances up to four fold the heterogeneous CO2 reduction to CO in water with an improved selectivity and stability compared to the mononuclear analogue. Interestingly, quasi-identical catalytic performances are obtained when one of the two iron centers was replaced by a redox inactive Zn metal, questioning the cooperative action of the two metals. Snapshots of X-ray structures indicate that the two metalloporphyrin units tethered by a urea group is a good compromise between rigidity and flexibility to accommodate CO2 capture, activation, and reduction. 相似文献