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961.
Xingtao Wang Yong Wang Taiyang Zhang Xiaomin Liu Yixin Zhao 《Angewandte Chemie (International ed. in English)》2020,59(4):1469-1473
The reduced dimension perovskite including 2D perovskites are one of the most promising strategies to stabilize lead halide perovskite. A mixed‐cation 2D perovskite based on a steric phenyltrimethylammonium (PTA) cation is presented. The PTA‐MA mixed‐cation 2D perovskite of PTAMAPbI4 can be formed on the surface of MAPbI3 (PTAI‐MAPbI3) by controllable PTAI intercalation by either spin coating or soaking. The PTAMAPbI4 capping layer can not only passivate PTAI‐MAPbI3 perovskite but also act as MA+ locker to inhibit MAI extraction and significantly enhance the stability. The highly stable PTAI‐MAPbI3 based perovskite solar cells exhibit a reproducible photovoltaic performance with a champion PCE of 21.16 %. Such unencapsulated devices retain 93 % of initial efficiency after 500 h continuous illumination. This steric mixed‐cation 2D perovskite as MA+ locker to stabilize the MAPbI3 is a promising strategy to design stable and high‐performance hybrid lead halide perovskites. 相似文献
962.
Yao Xiao Yan‐Fang Zhu Wei Xiang Zhen‐Guo Wu Yong‐Chun Li Jing Lai Shi Li Enhui Wang Zu‐Guang Yang Chun‐Liu Xu Ben‐He Zhong Xiao‐Dong Guo 《Angewandte Chemie (International ed. in English)》2020,59(4):1491-1495
Demands for large‐scale energy storage systems have driven the development of layered transition‐metal oxide cathodes for room‐temperature rechargeable sodium ion batteries (SIBs). Now, an abnormal layered‐tunnel heterostructure Na0.44Co0.1Mn0.9O2 cathode material induced by chemical element substitution is reported. By virtue of beneficial synergistic effects, this layered‐tunnel electrode shows outstanding electrochemical performance in sodium half‐cell system and excellent compatibility with hard carbon anode in sodium full‐cell system. The underlying formation process, charge compensation mechanism, phase transition, and sodium‐ion storage electrochemistry are clearly articulated and confirmed through combined analyses of in situ high‐energy X‐ray diffraction and ex situ X‐ray absorption spectroscopy as well as operando X‐ray diffraction. This crystal structure engineering regulation strategy offers a future outlook into advanced cathode materials for SIBs. 相似文献
963.
Jing Guo Yan‐Zhong Fan Yu‐Lin Lu Shao‐Ping Zheng Cheng‐Yong Su 《Angewandte Chemie (International ed. in English)》2020,59(22):8661-8669
Although the photodimerization of acenaphthylene (ACE) has been known for 100 years, the asymmetric cycloaddition of its 1‐substituted derivatives is unknown. Herein, we report a supramolecular photochirogenic approach in which a homochiral and photoactive Δ/Λ‐[Pd6(RuL3)8]28+ metal–organic cage (Δ/Λ‐MOC‐16) is used as a supramolecular reactor for the enantioselective exited‐state photocatalysis of 1‐Br‐ACE. Owing to preorganization of the substrates by the supramolecular cage, stereochemical control of the triplet state, and nanospace transfer of energy and chirality, the cycloaddition of ACE proceeded with high selectivity for the formation of anti over syn stereoisomers, whereas the regio‐, stereo‐, and enantioselective cycloaddition of unsymmetrical 1‐Br‐ACE showed effective enantiodifferentiation of a pair of anti head‐to‐head stereoisomers. The enzyme‐mimicking photocatalysis was verified by catalytic turnover, rate enhancement, and competing‐guest inhibition experiments. 相似文献
964.
Jian‐Gong Yang Kai Li Jian Wang Shanshan Sun Weijie Chi Chao Wang Xiaoyong Chang Chao Zou Wai‐Pong To Ming‐De Li Xiaogang Liu Wei Lu Hong‐Xing Zhang Chi‐Ming Che Yong Chen 《Angewandte Chemie (International ed. in English)》2020,59(17):6915-6922
Materials exhibiting excitation wavelength‐dependent photoluminescence (Ex‐De PL) in the visible region have potential applications in bioimaging, optoelectronics and anti‐counterfeiting. Two multifunctional, chiral [Au(NHC)2][Au(CN)2] (NHC=(4R,5R)/(4S,5S)‐1,3‐dimethyl‐4,5‐diphenyl‐4,5‐dihydro‐imidazolin‐2‐ylidene) complex double salts display Ex‐De circularly polarized luminescence (CPL) in doped polymer films and in ground powder. Emission maxima can be dynamically tuned from 440 to 530 nm by changing the excitation wavelength. The continuously tunable photoluminescence is proposed to originate from multiple emissive excited states as a result of the existence of varied AuI???AuI distances in ground state. The steric properties of the NHC ligand are crucial to the tuning of AuI???AuI distances. An anti‐counterfeiting application using these two salts is demonstrated. 相似文献
965.
Jie Yang Xiao‐Ming Zhang Fu‐Min Zhang Shao‐Hua Wang Yong‐Qiang Tu Zhen Li Xi‐Chao Wang Hong Wang 《Angewandte Chemie (International ed. in English)》2020,59(22):8471-8475
An enantioselective aldehyde α‐alkylation/semipinacol rearrangement was achieved through organo‐SOMO catalysis. The catalytically generated enamine radical cation serves as a carbon radical electrophile that can stereoselectively add to the alkene of an allylic alcohol and initiate ensuing ring‐expansion of cyclopropanol or cyclobutanol. This tandem reaction enables the production of a wide range of nonracemic functionalizable α‐quaternary‐δ‐carbonyl cycloketones in high yields and excellent enantioselectivity from simple aldehydes and allylic alcohols. As a key step, the intramolecular reaction was also successfully applied in the asymmetric total synthesis of (+)‐cerapicol. 相似文献
966.
Xu‐Shuang Han Xinqi Luan Hai‐Feng Su Jiao‐Jiao Li Shang‐Fu Yuan Zhen Lei Yong Pei Quan‐Ming Wang 《Angewandte Chemie (International ed. in English)》2020,59(6):2309-2312
An alkynyl‐protected gold nanocluster, Au22(tBuC≡C)18 ( 1 ), has been synthesized and its structure has been determined by single‐crystal X‐ray diffraction. The molecular structure consists of a Au13 cuboctahedron kernel and three [Au3(tBuC≡C)4] trimeric staples. The cluster 1 has strong luminescence in the solid state with a 15 % quantum yield, and it displays interesting thermochromic luminescence as revealed by temperature‐dependent emission spectra. The enhanced room‐temperature emission is characterized as thermally activated delayed fluorescence. 相似文献
967.
Kai Wu Kang Li Sha Chen Ya‐Jun Hou Yu‐Lin Lu Jing‐Si Wang Mei‐Juan Wei Mei Pan Cheng‐Yong Su 《Angewandte Chemie (International ed. in English)》2020,59(7):2639-2643
A nanocage coupling effect from a redox RuII‐PdII metal–organic cage (MOC‐16) is demonstrated for efficient photochemical H2 production by virtue of redox–guest modulation of the photo‐induced electron transfer (PET) process. Through coupling with photoredox cycle of MOC‐16, tetrathiafulvalene (TTF) guests act as electron relay mediator to improve the overall electron transfer efficiency in the host–guest system in a long‐time scale, leading to significant promotion of visible‐light driven H2 evolution. By contrast, the presence of larger TTF‐derivatives in bulk solution without host–guest interactions results in interference with PET process of MOC‐16, leading to inefficient H2 evolution. Such interaction provides an example to understand the interplay between the redox‐active nanocage and guest for optimization of redox events and photocatalytic activities in a confined chemical nanoenvironment. 相似文献
968.
Pan Yong Qi Ronghua He Pei Shen Ruiqing Jiang Jiajia Ni Lei Jiang Juncheng Wang Qingsheng 《Journal of Thermal Analysis and Calorimetry》2020,140(5):2575-2583
Journal of Thermal Analysis and Calorimetry - Chemical reactivity hazards of organic peroxides are major concerns of the chemical industry due to many serious incidents every year. Thermal hazard... 相似文献
969.
Xie Qiang Xie Yong Liu Wei Zhang Lei Li Shi Chen Houhe 《Journal of Thermal Analysis and Calorimetry》2020,140(4):1801-1810
Journal of Thermal Analysis and Calorimetry - To provide a theoretical basis for improving the thermal safety of spent acid, its decomposition behaviour was studied. A mixed solution of n-propyl... 相似文献
970.
Liu Yu Wang Yong Li Guangqiang Yuan Cheng Lu Ru Li Baokuan 《Journal of Thermal Analysis and Calorimetry》2020,139(2):923-931
Journal of Thermal Analysis and Calorimetry - The structure, vaporization behavior and crystallization of CaF2–CaO–Al2O3 slags with different SiO2 contents for electroslag remelting... 相似文献