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991.
Dr. Xianfu Wang Yiming Xie Kai Tang Chao Wang Prof. Chenglin Yan 《Angewandte Chemie (International ed. in English)》2018,57(36):11569-11573
Hydrogen ions are ideal charge carriers for rechargeable batteries due to their small ionic radius and wide availability. However, little attention has been paid to hydrogen‐ion storage devices because they generally deliver relatively low Coulombic efficiency as a result of the hydrogen evolution reaction that occurs in an aqueous electrolyte. Herein, we successfully demonstrate that hydrogen ions can be electrochemically stored in an inorganic molybdenum trioxide (MoO3) electrode with high Coulombic efficiency and stability. The as‐obtained electrode exhibits ultrafast hydrogen‐ion storage properties with a specific capacity of 88 mA hg?1 at an ultrahigh rate of 100 C. The redox reaction mechanism of the MoO3 electrode in the hydrogen‐ion cell was investigated in detail. The results reveal a conversion reaction of the MoO3 electrode into H0.88MoO3 during the first hydrogen‐ion insertion process and reversible intercalation/deintercalation of hydrogen ions between H0.88MoO3 and H0.12MoO3 during the following cycles. This study reveals new opportunities for the development of high‐power energy storage devices with lightweight elements. 相似文献
992.
Highly Enantioselective Tandem Michael Addition of Tryptamine‐Derived Oxindoles to Alkynones: Concise Synthesis of Strychnos Alkaloids 下载免费PDF全文
Weigang He Jiadong Hu Pengyan Wang Le Chen Kai Ji Siyu Yang Yin Li Zhilong Xie Prof. Dr. Weiqing Xie 《Angewandte Chemie (International ed. in English)》2018,57(14):3806-3809
A highly enantioselective tandem Michael addition of tryptamine‐derived oxindoles to alkynones was developed by taking advantage of a chiral N,N′‐dioxide Sc(OTf)3 catalyst. The reaction enables the facile preparation of enantioenriched spiro[pyrrolidine‐3,3′‐oxindole] compounds, which provides a novel strategy for the synthesis of monoterpenoid indole alkaloids. As a demonstration, the asymmetric synthesis of strychnos alkaloids [(?)‐tubifoline, (?)‐tubifolidine, (?)‐dehydrotubifoline] was achieved in 10–11 steps. 相似文献
993.
Facile,Quick, and Gram‐Scale Synthesis of Ultralong‐Lifetime Room‐Temperature‐Phosphorescent Carbon Dots by Microwave Irradiation 下载免费PDF全文
Kai Jiang Dr. Yuhui Wang Xiaolu Gao Prof. Congzhong Cai Prof. Hengwei Lin 《Angewandte Chemie (International ed. in English)》2018,57(21):6216-6220
Long‐lifetime room‐temperature phosphorescence (RTP) materials are important for many applications, but they are highly challenging materials owing to the spin‐forbidden nature of triplet exciton transitions. Herein, a facile, quick and gram‐scale method for the preparation of ultralong RTP (URTP) carbon dots (CDs) was developed via microwave‐assisted heating of ethanolamine and phosphoric acid aqueous solution. The CDs exhibit the longest RTP lifetime, 1.46 s (more than 10 s to naked eye) for CDs‐based materials to date. The doping of N and P elements is critical for the URTP which is considered to be favored by a n→π* transition facilitating intersystem crossing (ISC) for effectively populating triplet excitons. In addition, possibilities of formation of hydrogen bonds in the interior of the CDs may also play a significant role in producing RTP. Potential applications of the URTP CDs in the fields of anti‐counterfeiting and information protection are proposed and demonstrated. 相似文献
994.
Prof. Dr. Petra Schwille Prof. Dr. Joachim Spatz Prof. Dr. Katharina Landfester Prof. Dr. Eberhard Bodenschatz Prof. Dr. Stephan Herminghaus Prof. Dr. Victor Sourjik Dr. Tobias J. Erb Prof. Dr. Philippe Bastiaens Prof. Dr. Reinhard Lipowsky Prof. Dr. Anthony Hyman Prof. Dr. Peter Dabrock Dr. Jean‐Christophe Baret Dr. Tanja Vidakovic‐Koch Dr. Peter Bieling Dr. Rumiana Dimova Dr. Hannes Mutschler Dr. Tom Robinson Dr. T.‐Y. Dora Tang Dr. Seraphine Wegner Prof. Dr. Kai Sundmacher 《Angewandte Chemie (International ed. in English)》2018,57(41):13382-13392
A large German research consortium mainly within the Max Planck Society (“MaxSynBio”) was formed to investigate living systems from a fundamental perspective. The research program of MaxSynBio relies solely on the bottom‐up approach to synthetic biology. MaxSynBio focuses on the detailed analysis and understanding of essential processes of life through modular reconstitution in minimal synthetic systems. The ultimate goal is to construct a basic living unit entirely from non‐living components. The fundamental insights gained from the activities in MaxSynBio could eventually be utilized for establishing a new generation of biotechnological processes, which would be based on synthetic cell constructs that replace the natural cells currently used in conventional biotechnology. 相似文献
995.
Hydrogen peroxide and lipid hydroperoxides are formed during aerobic metabolism and contribute to oxidative stress, a major factor in many diseases and degenerative conditions. Although the selenoenzyme glutathione peroxidase (GPx) affords antioxidant protection in vivo by catalytically reducing harmful peroxides with glutathione, certain conditions benefit from the administration of small-molecule GPx mimetics for additional protection. To date, ebselen has been the most widely studied such compound, but its catalytic mechanism is complex and highly variable with conditions. Progress in elucidating the mechanistic details of its antioxidant activity is described in this review. 相似文献
996.
Efficient CO2 Removal for Ultra‐Pure CO Production by Two Hybrid Ultramicroporous Materials 下载免费PDF全文
Dr. Kai‐Jie Chen Dr. Qing‐Yuan Yang Dr. Susan Sen Dr. David G. Madden Amrit Kumar Dr. Tony Pham Katherine A. Forrest Dr. Nobuhiko Hosono Prof. Dr. Brian Space Prof. Dr. Susumu Kitagawa Prof. Dr. Michael J. Zaworotko 《Angewandte Chemie (International ed. in English)》2018,57(13):3332-3336
Removal of CO2 from CO gas mixtures is a necessary but challenging step during production of ultra‐pure CO as processed from either steam reforming of hydrocarbons or CO2 reduction. Herein, two hybrid ultramicroporous materials (HUMs), SIFSIX‐3‐Ni and TIFSIX‐2‐Cu‐i , which are known to exhibit strong affinity for CO2, were examined with respect to their performance for this separation. The single‐gas CO sorption isotherms of these HUMs were measured for the first time and are indicative of weak affinity for CO and benchmark CO2/CO selectivity (>4000 for SIFSIX‐3‐Ni ). This prompted us to conduct dynamic breakthrough experiments and compare performance with other porous materials. Ultra‐pure CO (99.99 %) was thereby obtained from CO gas mixtures containing both trace (1 %) and bulk (50 %) levels of CO2 in a one‐step physisorption‐based separation process. 相似文献
997.
CO2‐Triggered Switchable Hydrophilicity of a Heterogeneous Conjugated Polymer Photocatalyst for Enhanced Catalytic Activity in Water 下载免费PDF全文
Dr. Jeehye Byun Wei Huang Di Wang Run Li Dr. Kai A. I. Zhang 《Angewandte Chemie (International ed. in English)》2018,57(11):2967-2971
Water compatibility for heterogeneous photocatalysts has been pursued for energy and environmental applications. However, there exists a trade‐off between hydrophilicity and recyclability of the photocatalyst. Herein, we report a conjugated polymer photocatalyst with tertiary amine terminals that reversibly binds CO2 in water, thereby generating switchable hydrophilicity. The CO2‐assisted hydrophilicity boosted the photocatalytic efficiency in aqueous medium with minimum dosage. When CO2 was desorbed, the photocatalyst could be simply regenerated from reaction media, facilitating the repeated use of photocatalyst. Hydrophilicity/hydrophobicity control of the polymer photocatalyst was successfully showcased through a variety of organic photoredox reactions under visible‐light irradiation in water. 相似文献
998.
Imaging of Colorectal Cancers Using Activatable Nanoprobes with Second Near‐Infrared Window Emission 下载免费PDF全文
Ge Xu Qinglong Yan Xiaoguang Lv Prof. Ying Zhu Kai Xin Ben Shi Rongchen Wang Jian Chen Wei Gao Prof. Ping Shi Prof. Chunhai Fan Prof. Chunchang Zhao Prof. He Tian 《Angewandte Chemie (International ed. in English)》2018,57(14):3626-3630
Fluorescent probes in the second near‐infrared window (NIR‐II) allow high‐resolution bioimaging with deep‐tissue penetration. However, existing NIR‐II materials often have poor signal‐to‐background ratios because of the lack of target specificity. Herein, an activatable NIR‐II nanoprobe for visualizing colorectal cancers was devised. This designed probe displays H2S‐activated ratiometric fluorescence and light‐up NIR‐II emission at 900–1300 nm. By using this activatable and target specific probe for deep‐tissue imaging of H2S‐rich colon cancer cells, accurate identification of colorectal tumors in animal models were performed. It is anticipated that the development of activatable NIR‐II probes will find widespread applications in biological and clinical systems. 相似文献
999.
1000.
The aggregation and assembly of crescent oligoamides with two to six benzene residues are investigated. In chloroform, the pentamer and hexamer are found to associate into large aggregates. In the solid state, all oligomers examined associate into columnar assemblies via stacking interactions, as shown by X-ray diffraction data from single crystals and powder samples. The columnar assemblies of the pentamer and hexamer should contain hydrophilic channels defined by the constituent oligomers. 相似文献