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91.
采用超高效液相色谱-四极杆飞行时间质谱(UPLC-Q-TOF MS/MS)技术,建立了睫毛用化妆品中9种前列腺素F2α类化合物(比马前列素、曲伏前列素、他氟前列素、他氟乙酰胺、拉坦前列素、比马前列素酸甲基酯、氯前列醇异丙基酯、15-酮-曲伏前列素、比马酰胺)的快速定性筛查方法。样品经乙腈超声提取,采用Waters ACQUITY UPLC BEH C18(2.1 mm×100 mm,1.7μm)色谱柱,以2 mmol/L甲酸铵水溶液(含0.05%甲酸)-乙腈为流动相,分离后进入四极杆飞行时间质谱,采用电喷雾离子源正离子模式(ESI+),以MSE模式进行数据采集,建立了9种前列腺素F2α类化合物的筛查数据库。9种化合物在各自质量浓度范围内线性关系良好,相关系数(r2)均大于0.99,检出限为0.075~0.75μg/g,定量下限为0.25~2.5μg/g。所建立的筛查数据库无需对照品即可对化妆品中的9种前列腺素F2α类化合物进行筛查。结果表明,该方法特异性良好,应用于48批睫毛类化妆品的定性筛查具有良好的选择性,可为化妆品中前列腺素F2α类化合物的筛查分析提供技术支... 相似文献
92.
The mechanism is investigated for CptBuRh(OH)2-catalyzed annulation of 2-biphenylboronic acid with three activated alkenes using M06-2X functional. The reaction comprises transmetalation via two steps and following C-H activation producing reactive Rh-biphenyl complex with two Rh—C σ bonds. After the coordination/insertion of alkenes, respective fused or bridged cyclic products are yielded depending on different alkenes accompanied by the release of CptBuRh. The promotion of CptBuRh(OH)2 lies in the barrier decrease of transmetalation and C-H activation ready for coordination/insertion ensuring the smooth progress of common rate-limiting reductive elimination. The stereoselective transfer and ring rotation are specific for benzoquinone and cyclopropenone. The role of Rh(III) catalyst and release of Rh(I) is supported by Multiwfn analysis on frontier molecular orbital(FMO) of specific transiton states(TSs) and Mayer bond order(MBO) value of vital bonding, breaking. 相似文献
93.
94.
Jiehao Du Banggui Cheng Huiqing Yuan Yuan Tao Ya Chen Mei Ming Zhiji Han Richard Eisenberg 《Angewandte Chemie (International ed. in English)》2023,62(9):e202211804
We report the unprecedented electrocatalytic activity of a series of molecular nickel thiolate complexes ( 1 – 5 ) in reducing CO2 to C1–3 hydrocarbons on carbon paper in pH-neutral aqueous solutions. Ni(mpo)2 ( 3 , mpo=2-mercaptopyridyl-N-oxide), Ni(pyS)3− ( 4 , pyS=2-mercaptopyridine), and Ni(mp)2− ( 5 , mp=2-mercaptophenolate) were found to generate C3 products from CO2 for the first time in molecular complex. Compound 5 exhibits Faradaic efficiencies (FEs) of 10.6 %, 7.2 %, 8.2 % for C1, C2, C3 hydrocarbons respectively at −1.0 V versus the reversible hydrogen electrode. Addition of CO to the system significantly promotes the FEC1–C3 to 41.1 %, suggesting that a key Ni−CO intermediate is associated with catalysis. A variety of spectroscopies have been performed to show that the structures of nickel complexes remain intact during CO2 reduction. 相似文献
95.
Dr. Songlin Xue Dr. W. Ryan Osterloh Xiaojuan Lv Ningchao Liu Yimei Gao Dr. Haitao Lei Dr. Yuanyuan Fang Dr. Zhongti Sun Dr. Peifeng Mei Dr. Daiki Kuzuhara Dr. Naoki Aratani Dr. Hiroko Yamada Dr. Rui Cao Dr. Karl M. Kadish Dr. Fengxian Qiu 《Angewandte Chemie (International ed. in English)》2023,62(17):e202218567
The molecular structure, electrochemistry, spectroelectrochemistry and electrocatalytic oxygen reduction reaction (ORR) features of two CoII porphyrin(2.1.2.1) complexes bearing Ph or F5Ph groups at the two meso-positions of the macrocycle are examined. Single crystal X-ray analysis reveal a highly bent, nonplanar macrocyclic conformation of the complex resulting in clamp-shaped molecular structures. Cyclic voltammetry paired with UV/Vis spectroelectrochemistry in PhCN/0.1 M TBAP suggest that the first electron addition corresponds to a macrocyclic-centered reduction while spectral changes observed during the first oxidation are consistent with a metal-centered CoII/CoIII process. The activity of the clamp-shaped complexes towards heterogeneous ORR in 0.1 M KOH show selectivity towards the 4e− ORR pathway giving H2O. DFT first-principle calculations on the porphyrin catalyst indicates a lower overpotential for 4e− ORR as compared to the 2e− pathway, consistent with experimental data. 相似文献
96.
Tao Song Dr. Da Wang Prof. Hongxia Wang Dr. Jia Yu Prof. Siqi Shi 《Angewandte Chemie (International ed. in English)》2023,62(31):e202305004
Integrating the advantages of both inorganic ceramic and organic polymer solid-state electrolytes, small-molecule solid-state electrolytes represented by LiI-3-hydroxypropionitrile (LiI-HPN) inorganic–organic hybrid systems possess good interfacial compatibility and high modulus. However, their lack of intrinsic Li+ conduction ability hinders potential application in lithium metal batteries until now, despite containing LiI phase composition. Herein, inspired by evolution tendency of ionic conduction behaviors together with first-principles molecular dynamics simulations, we propose a stepped-amorphization strategy to break the Li+ conduction bottleneck of LiI-HPN. It involves three progressive steps of composition (LiI-content increasing), time (long-time standing), and temperature (high-temperature melting) regulations, to essentially construct a small-molecule-based composite solid-state electrolyte with intensified amorphous degree, which realizes efficient conversion from an I− to Li+ conductor and improved conductivity. As a proof, the stepped-optimized LiI-HPN is successfully operated in lithium metal batteries cooperated with Li4Ti5O12 cathode to deliver considerable compatibility and stability over 250 cycles. This work not only clarifies the ionic conduction mechanisms of LiI-HPN inorganic–organic hybrid systems, but also provides a reasonable strategy to broaden the application scenarios of highly compatible small-molecule solid-state electrolytes. 相似文献
97.
Jing Cao Tong Mou Bingbao Mei Pengfei Yao Ce Han Xue Gong Ping Song Prof. Zheng Jiang Prof. Thomas Frauenheim Prof. Jianping Xiao Prof. Weilin Xu 《Angewandte Chemie (International ed. in English)》2023,62(43):e202310973
Full understanding to the origin of the catalytic performance of a supported nanocatalyst from the points of view of both the active component and support is significant for the achievement of high performance. Herein, based on a model electrocatalyst of single-iridium-atom-doped iron (Fe)-based layered double hydroxides (LDH) for oxygen evolution reaction (OER), we reveal the first completed origin of the catalytic performance of such supported nanocatalysts. Specially, besides the activity enhancement of Ir sites by LDH support, the stability of surface Fe sites is enhanced by doped Ir sites: DFT calculation shows that the Ir sites can reduce the activity and enhance the stability of the nearby Fe sites; while further finite element simulations indicate, the stability enhancement of distant Fe sites could be attributed to the much low concentration of OER reactant (hydroxyl ions, OH−) around them induced by the much fast consumption of OH− on highly active Ir sites. These new findings about the interaction between the main active components and supports are applicable in principle to other heterogeneous nanocatalysts and provide a completed understanding to the catalytic performance of heterogeneous nanocatalysts. 相似文献
98.
Prof. Xiaona Li Yang Xu Prof. Changtai Zhao Duojie Wu Dr. Limin Wang Matthew Zheng Xu Han Dr. Simeng Zhang Junyi Yue Prof. Biwei Xiao Dr. Wei Xiao Dr. Ligen Wang Prof. Tao Mei Prof. Meng Gu Prof. Jianwen Liang Prof. Xueliang Sun 《Angewandte Chemie (International ed. in English)》2023,62(48):e202306433
As exciting candidates for next-generation energy storage, all-solid-state lithium batteries (ASSLBs) are highly dependent on advanced solid-state electrolytes (SSEs). Here, using cost-effective LaCl3 and CeCl3 lattice (UCl3-type structure) as the host and further combined with a multiple-cation mixed strategy, we report a series of UCl3-type SSEs with high room-temperature ionic conductivities over 10−3 S cm−1 and good compatibility with high-voltage oxide cathodes. The intrinsic large-size hexagonal one-dimensional channels and highly disordered amorphous phase induced by multi-metal cation species are believed to trigger fast multiple ionic conductions of Li+, Na+, K+, Cu+, and Ag+. The UCl3-type SSEs enable a stable prototype ASSLB capable of over 3000 cycles and high reversibility at −30 °C. Further exploration of the brand-new multiple-cation mixed chlorides is likely to lead to the development of advanced halide SSEs suitable for ASSLBs with high energy density. 相似文献
99.
Dr. Yanbo Mei Prof. Dr. Xiaodan Chen Dr. Rui Wei Dr. Xiao-Yong Chang Prof. Dr. Lizhi Tao Prof. Dr. Liu Leo Liu 《Angewandte Chemie (International ed. in English)》2023,62(52):e202315555
Featuring an extra electron in the π* antibonding orbital, species with a 2-center-3-electron (2c3e) π bond without an underlying σ bond are scarcely known. Herein, we report the synthesis, isolation and characterization of a radical anion salt [K(18-C-6)]+{[(HCNDipp)2Si]2P2}⋅− (i.e. [K(18-C-6)]+ 3 ⋅−) (18-C-6=18-crown-6, Dipp=2,6-diisopropylphenyl), in which 3 ⋅− features a perfectly planar Si2P2 four-membered ring. This species represents the first example of a Si- and P-containing analog of a bicyclo[1.1.0]butane radical anion. The unusual bonding motif of 3 ⋅− was thoroughly investigated via X-ray diffraction crystallography, electron paramagnetic resonance spectroscopy (EPR), and calculations by density functional theory (DFT), which collectively unveiled the existence of a 2c3e π bond between the bridgehead P atoms and no clearly defined supporting P−P σ bond. 相似文献
100.
Shanshan Sun Litao Wang Jiasheng Wang Wenjing Lv Qinghua Yu Dong Pei Siqi Han Xingyu Li Miao Wang Sheng Liu Xiangao Quan Mei Lv 《Journal of separation science》2023,46(16):2200935
In this work, homochiral reduced imine cage was covalently bonded to the surface of the silica to prepare a novel high-performance liquid chromatography stationary phase, which was applied for the multiple separation modes such as normal phase, reversed-phase, ion exchange, and hydrophilic interaction chromatography. The successful preparation of the homochiral reduced imine cage bonded silica stationary phase was confirmed by performing a series of methods including X-ray photoelectron spectroscopy, thermogravimetric analysis, and infrared spectroscopy. From the extracted results of the chiral resolution in normal phase and reversed-phase modes, it was demonstrated that seven chiral compounds were successfully separated, among which the resolution of 1-phenylethanol reached the value of 3.97. Moreover, the multifunctional chromatographic performance of the new molecular cage stationary phase was systematically investigated in the modes of reversed-phase, ion exchange, and hydrophilic interaction chromatography for the separation and analysis of a total of 59 compounds in eight classes. This work demonstrated that the homochiral reduced imine cage not only achieved multiseparation modes and multiseparation functions performance with high stability, but also expanded the application of the organic molecular cage in the field of liquid chromatography. 相似文献