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991.
Dr. Junning Kou Dr. Qi Wu Dr. Dongxu Cui Dr. Yun Geng Dr. Kunhao Zhang Prof. Dr. Min Zhang Prof. Dr. Hongying Zang Prof. Dr. Xinlong Wang Prof. Dr. Zhongmin Su Prof. Dr. Chunyi Sun 《Angewandte Chemie (International ed. in English)》2023,62(47):e202312733
Chiral induction has been an important topic in chemistry, not only for its relevance in understanding the mysterious phenomenon of spontaneous symmetry breaking in nature but also due to its critical implications in medicine and the chiral industry. The induced chirality of fullerenes by host–guest interactions has been rarely reported, mainly attributed to their chiral resistance from high symmetry and challenges in their accessibility. Herein, we report two new pairs of chiral porous aromatic cages (PAC), R- PAC-2 , S- PAC-2 (with Br substituents) and R- PAC-3 , S- PAC-3 (with CH3 substituents) enantiomers. PAC-2 , rather than PAC-3 , achieves fullerene encapsulation and selective binding of C70 over C60 in fullerene carbon soot. More significantly, the occurrence of chiral induction between R- PAC-2 , S- PAC-2 and fullerenes is confirmed by single-crystal X-ray diffraction and the intense CD signal within the absorption region of fullerenes. DFT calculations reveal the contribution of electrostatic effects originating from face-to-face arene-fullerene interactions dominate C70 selectivity and elucidate the substituent effect on fullerene encapsulation. The disturbance from the differential interactions between fullerene and surrounding chiral cages on the intrinsic highly symmetric electronic structure of fullerene could be the primary reason accounting for the induced chirality of fullerene. 相似文献
992.
Xi Su Zhiye Zhong Dr. Xiaoli Yan Dr. Ting Zhang Chuanzhe Wang Dr. Yi-Xuan Wang Prof. Gang Xu Prof. Long Chen 《Angewandte Chemie (International ed. in English)》2023,62(22):e202302645
As an emerging class of promising porous materials, the development of two-dimensional conductive metal organic frameworks (2D c-MOFs) is hampered by the few categories and tedious synthesis of the specific ligands. Herein, we developed a nonplanar hexahydroxyl-functionalized Salphen ligand (6OH-Salphen) through a facile two-step synthesis, which was further applied to construct layered 2D c-MOFs through in situ one pot synthesis based on the synergistic metal binding effect of the N2O2 pocket of Salphen. Interestingly, the C2v-symmetry of ligand endows Cu-Salphen-MOF with periodically heterogeneous pore structures. Benefitting from the higher metal density and shorter in-plane metal-metal distance, Cu-Salphen-MOF showcased excellent NO2 sensing performance with good sensitivity, selectivity and reversibility. The current work opens up a new avenue to construct 2D c-MOF directly from nonplanar ligands, which greatly simplifies the synthesis and provides new possibilities for preparing different topological 2D c-MOF based functional materials. 相似文献
993.
Xinlin Huang Chuang Wang Dr. Chuanfa Li Dr. Meng Liao Jiaxin Li Haibo Jiang Yao Long Xiangran Cheng Kun Zhang Pengzhou Li Prof. Bingjie Wang Prof. Huisheng Peng 《Angewandte Chemie (International ed. in English)》2023,62(24):e202303616
Fiber lithium-ion batteries represent a promising power strategy for the rising wearable electronics. However, most fiber current collectors are solid with vastly increased weights of inactive materials and sluggish charge transport, thus resulting in low energy densities which have hindered the development of fiber lithium-ion batteries in the past decade. Here, a braided fiber current collector with multiple channels was prepared by multi-axial winding method to not only increase the mass fraction of active materials, but also to promote ion transport along fiber electrodes. In comparison to typical solid copper wires, the braided fiber current collector hosted 139 % graphite with only 1/3 mass. The fiber graphite anode with braided current collector delivered high specific capacity of 170 mAh g−1 based on the overall electrode weight, which was 2 times higher than that of its counterpart solid copper wire. The resulting fiber battery showed high energy density of 62 Wh kg−1. 相似文献
994.
Dr. Chi Zhang Dr. Meiling Shao Dr. Dongqing Wu Dr. Zhongyi Li Muzhi Zhao Xiangfei Zhang Prof. Bin Zhai Prof. Yunjun Luo Prof. Xiaoyu Li 《Angewandte Chemie (International ed. in English)》2023,62(52):e202314052
Azide compounds are widely used and especially, polymers bearing pendant azide groups are highly desired in numerous fields. However, harsh reaction conditions are always mandatory to achieve full azidation, causing severe side reactions and degradation of the polymers. Herein, we report the design and preparation of two azide ionic liquids (AILs) with azide anion and triethylene glycol (E3)-containing cation, [P444E3][N3] and [MIME3][N3]. Compared with the traditional sodium azide (NaN3) approach, both AILs showed much higher reaction rates and functional-group tolerance. More importantly, they could act as both reagents and solvents for the quantitative azidation of various polymeric precursors under mild conditions. Theoretical simulations suggested that the outstanding performance of AILs originated from the existence of ion pairs during the reaction, and the E3 moieties played a crucial role. Lastly, after the reaction, the AILs could be easily regenerated, presenting a safer, greener, and highly efficient synthesis route for azide polymers. 相似文献
995.
Shenghao Li Jing Lin Mareen Schaller Sylvio Indris Xin Zhang Torsten Brezesinski Ce-Wen Nan Shuo Wang Florian Strauss 《Angewandte Chemie (International ed. in English)》2023,62(50):e202314155
Superionic solid electrolytes (SEs) are essential for bulk-type solid-state battery (SSB) applications. Multicomponent SEs are recently attracting attention for their favorable charge-transport properties, however a thorough understanding of how configurational entropy (ΔSconf) affects ionic conductivity is lacking. Here, we successfully synthesized a series of halogen-rich lithium argyrodites with the general formula Li5.5PS4.5ClxBr1.5-x (0≤x≤1.5). Using neutron powder diffraction and 31P magic-angle spinning nuclear magnetic resonance spectroscopy, the S2−/Cl−/Br− occupancy on the anion sublattice was quantitatively analyzed. We show that disorder positively affects Li-ion dynamics, leading to a room-temperature ionic conductivity of 22.7 mS cm−1 (9.6 mS cm−1 in cold-pressed state) for Li5.5PS4.5Cl0.8Br0.7 (ΔSconf=1.98R). To the best of our knowledge, this is the first experimental evidence that configurational entropy of the anion sublattice correlates with ion mobility. Our results indicate the possibility of improving ionic conductivity in ceramic ion conductors by tailoring the degree of compositional complexity. Moreover, the Li5.5PS4.5Cl0.8Br0.7 SE allowed for stable cycling of single-crystal LiNi0.9Co0.06Mn0.04O2 (s-NCM90) composite cathodes in SSB cells, emphasizing that dual-substituted lithium argyrodites hold great promise in enabling high-performance electrochemical energy storage. 相似文献
996.
Dr. Feifei Zhang Dr. Hua Shang Bolun Zhai Zhiwei Zhao Dr. Yong Wang Prof. Libo Li Prof. Jinping Li Prof. Jiangfeng Yang 《Angewandte Chemie (International ed. in English)》2023,62(50):e202316149
Porous materials with d3 electronic configuration open metal sites have been proved to be effective adsorbents for N2 capture and N2/O2 separation. However, the reported materials remain challenging to address the trade-off between adsorption capacity and selectivity. Herein, we report a robust MOF, MIL-102Cr, that features two binding sites, can synergistically afford strong interactions for N2 capture. The synergistic adsorption site exhibits a benchmark Qst of 45.0 kJ mol−1 for N2 among the Cr-based MOFs, a record-high volumetric N2 uptake (31.38 cm3 cm−3), and highest N2/O2 selectivity (13.11) at 298 K and 1.0 bar. Breakthrough experiments reveal that MIL-102Cr can efficiently capture N2 from a 79/21 N2/O2 mixture, providing a record 99.99 % pure O2 productivity of 0.75 mmol g−1. In situ infrared spectroscopy and computational modelling studies revealed that a synergistic adsorption effect by open Cr(III) and fluorine sites was accountable for the strong interactions between the MOF and N2. 相似文献
997.
Hongbin Dai Prof. Ran Hong Yafei Ma Dr. Xiaoxiao Cheng Prof. Wei Zhang 《Angewandte Chemie (International ed. in English)》2023,62(50):e202314848
Precise control over the chirality and morphologies of polymer assemblies, a remaining challenge for both chemists and materials scientists, is receiving ever-increasing attention in the recent years. Herein, we report the subtle manipulation of the achiral spacers from the chiral stereocenter to the azobenzene (Azo) unit, of which the chiroptical consistency or chiroptical inversion of self-assemblies could be successfully controlled and present “two-fold” odd-even effect. Furthermore, morphological transitions from 0D spherical micelles, 1D worms, and nanowires to 3D vesicles, spindle- and dumbbell-shaped vesicles were also unexpectedly found to exhibit odd-even correlations. These observations were collectively elucidated by mesomorphic properties, stacking modes, chiroptical dynamics, and stimuli-responsive behaviors. Negligible modifications to the spacer structures can enable remarkable modulation of supramolecular chirality and anisotropic topologies in polymer assemblies, which is of great significance for the design of complex chiral functional polymers. 相似文献
998.
Ziqi Zhu Di Zhang Tongtong Xiao Yu-Hui Fang Xiao Xiao Xiao-Ge Wang Prof. Shang-Da Jiang Prof. Dahui Zhao 《Angewandte Chemie (International ed. in English)》2023,62(49):e202314900
Stable carbon-based polyradicals exhibiting strong spin-spin coupling and slow depolarization processes are particularly attractive functional materials. A new molecular motif synthesized by a convenient method that allows the integration of stable, high-spin radicals to (hetero)aromatic polycycles has been developed, as illustrated by a non-Kekulé diradical showing a triplet ground state with long persistency (τ1/2≈31 h) in air. Compared to the widely used 1,3-phenylene, the newly designed (diaza)pyrene-4,10-diyl moiety is for the first time demonstrated to confer ferromagnetic (FM) spin coupling, allowing delocalized non-disjoint SOMOs. With the X-ray crystallography unambiguously proving the diradical structure, the triplet ground state was thoroughly characterized. A large ΔES-T of 1.1 kcal/mol, proving the strong FM coupling effect, was revealed consistently by superconducting quantum interference device (SQUID) measurements and variable-temperature electron paramagnetic resonance (EPR) spectroscopy, while the zero-field splitting and triplet nutation characters were examined by continuous-wave and pulsed EPR spectroscopy. A millisecond spin-lattice relaxation time was also detected. The current study not only offers a new molecular motif enabling FM coupling between carbon-based spins, but more importantly presents a general method for installing stable polyradicals into functional π-systems. 相似文献
999.
Lu Luo Shuai Tang Jiangyue Wu Shiwei Jin Hua Zhang 《Chemical record (New York, N.Y.)》2023,23(4):e202300023
Aromatic organoboron compounds are highly valuable building blocks in organic chemistry. They were mainly synthesized through aromatic C−H and C−Het borylation, in which transition metal-catalysis dominate. In the past decade, with increasing attention to sustainable chemistry, numerous transition metal-free C−H and C−Het borylation transformations have been developed and emerged as efficient methods towards the synthesis of aromatic organoboron compounds. This account mainly focuses on recent advances in transition metal-free aromatic C−H, C−N, C−S, and C−O borylation transformations and provides insights to where further developments are required. 相似文献
1000.
Bing-Chiuan Shiu Shihan Wulin Qian-Yu Yuan Ying Zhang Zhicai Yu 《Macromolecular bioscience》2023,23(11):2300233
In this study, lacquer is gathered from a lacquer tree and rotary evaporation is used to remove impurities to obtain urushiol. Next, 10 mL of anhydrous ethanol serves as the solvent for blending polyvinylpyrrolidone (PVP) at a specified content (0.7 g and 0.2–0.7 g urushiol) to form an electrospinning solution. Electrospinning is carried out with a voltage of 18 kV to prepare PVP/urushiol nanofibrous membranes. At a ratio of 7/4, the PVP/urushiol nanofibrous membranes are not eroded in 98% sulfuric acid and these membranes also demonstrate a 50–60% antibacterial effect against Staphylococcus aureus and Escherichia coli. Moreover, the antibacterial effect can be boosted to 98% with the incorporation of zinc ions. The results indicate that anhydrous ethanol can remove the sensitization of urushiol from PVP/urushiol membranes. Furthermore, animal test results indicate that when rats are in contact with PVP/urushiol anhydrous ethanol for 48 h, their skins are free from dark brown skin allergy. The presence of PVP eliminates the sensitization of urushiol, and the nanofibrous membranes demonstrate low toxicity. Hence, urushiol is the only natural material that enables PVP to withstand 98% sulfuric acid as well as acquire hydrolyzability, thereby qualify PVP as a medical material. 相似文献