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51.
Xudong Hou Giang Truong Nguyen Tingting Xu Dr. Haipeng Wei Dr. Tun Seng Herng Dr. Guifei Huo Dr. Dingguan Wang Prof. Jun Ding Dr. Shaofei Wu Prof. Liviu Ungur Prof. Jishan Wu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(31):e202200687
The incorporation of organic radicals into coordination polymers was considered as a promising strategy to promote metal-ligand exchange interactions, but there are only a very limited number of stable organic radical-based ligands that can serve well such a purpose. Herein, we report two new tris(2,4,6-trichlorophenyl)methyl (TTM) radical-based ligands L1 and L2 with two and three imidazole substituents, respectively. The imidazole unit serves as a coordination site and it can also stabilize the TTM radical by intramolecular donor–acceptor interaction. Coordination of L1 and L2 with cobalt(II) ions gave the corresponding one- ( CoCP - 1 ) and two-dimensional ( CoCP - 2 ) coordination polymers, the structures of which were confirmed by X-ray crystallographic analysis. Magnetic measurements and theoretical calculations suggest antiferromagnetic coupling between the paramagnetic cobalt(II) ions and the radical ligands. Our study provides a rational design for stable organic radical-based ligands and further demonstrated the feasibility of a metal–radical approach toward magnetic materials. 相似文献
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We prove the uniqueness of weak solutions of the 3‐D time‐dependent Ginzburg‐Landau equations for super‐conductivity with initial data (ψ0, A0)∈ L2 under the hypothesis that (ψ, A) ∈ Ls(0, T; Lr,∞) × (0, T; with Coulomb gauge for any (r, s) and satisfying + = 1, + = 1, ≥ , ≥ and 3 < r ≤ 6, 3 < ≤ ∞. Here Lr,∞ ≡ is the Lorentz space. As an application, we prove a uniqueness result with periodic boundary condition when ψ0 ∈ , A0 ∈ L3 (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Xuefeng Lu Dongyue An Yi Han Ya Zou Yanjun Qiao Ning Zhang Dongdong Chang Jishan Wu Yunqi Liu 《Chemical science》2021,12(11):3952
A cyclopenta-fused macrocyclic tetraradicaloid, MC4-S, containing alternating phenanthrene (Phen) and dibenzo[b,d]thiophene (DBTh) units was synthesized and isolated in single-crystal form. Compared with its all-carbon isoelectronic structure, CPTP-M, the incorporation of two sulfur atoms leads to a smaller radical character and a larger singlet–triplet energy gap. X-ray crystallographic analysis reveals that the spin–spin coupling through the DBTh unit is stronger than that through the Phen moiety. In addition, the electron-rich sulfur atoms also raise the energies of both the HOMO and LUMO in MC4-S, but the overall optical and electronic energy gaps are close to that of the CPTP-M. MC4-S displays global anti-aromaticity according to the NMR measurements and theoretical calculations (NICS, ACID and 2D ICSS), with a 36π ring current circuit along the all-carbon periphery excluding the two sulphur atoms. Its dication becomes globally aromatic due to the existence of a dominant 34π-conjugation pathway. This study sheds some light on the effect of heteroatoms on the electronic properties of open-shell polyradicaloids.The first member of sulfur-heterocycloarene neutral tetraradicaloids, MC4-S, was synthesized in crystalline form, which displays strong global anti-aromaticity and unique properties. 相似文献
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We consider the compressible magnetohydrodynamic (MHD) equations with nonnegative thermal conductivity or infinite electric conductivity. We prove the existence of unique local strong solutions for all initial data satisfying some compatibility condition. The initial density need not be positive and may vanish in an open set. 相似文献
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Ya Zou Víctor Bonal Sergio Moles Quintero Dr. Pedro G. Boj Dr. José M. Villalvilla Dr. José A. Quintana Dr. Guangwu Li Shaofei Wu Dr. Qing Jiang Dr. Yong Ni Prof. Juan Casado Prof. María A. Díaz-García Prof. Jishan Wu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(35):15037-15044
Perylene-fused, aggregation-free polycyclic aromatic hydrocarbons with partial zigzag periphery ( ZY-01 , ZY-02 , and ZY-03 ) were synthesized. X-ray crystallographic analysis reveals that there is no intermolecular π–π stacking in any of the three molecules, and as a result, they show moderate-to-high photoluminescence quantum yield in both solution and in the solid state. They also display the characteristic absorption and emission spectra of perylene dyes. ZY-01 and ZY-02 with a nearly planar π-conjugated skeleton exhibit amplified spontaneous emission (ASE) when dispersed in polystyrene thin films. Solution-processed distributed feedback lasers have been fabricated using ZY-01 and ZY-02 as active gain materials, both showing narrow emission linewidth (<0.4 nm) at wavelengths around 515 and 570 nm, respectively. In contrast, ZY-03 did not show ASE and lasing, presumably due to its highly twisted backbone, which facilitates nonradiative internal conversion and intersystem crossing. 相似文献
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This note proves a regularity criterion ∇b∈L1(0,T;BMO(R2)) for the 2D MHD system with zero magnetic diffusivity. 相似文献
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通过对模拟窜气技术的更新,研制成功一种具有双通道反应体系的DWY-I型低温油泥试验仪,并且在这种试验仪上,对影响试验结果的温度、时间、引发剂用量、模拟窜气中NOx的含量和水分等因素进行了优化筛选,建立了一种评价油品低温分散性能的实验室模拟试验方法,以NO在线合成NO2替代常用的气瓶NO2,解决了气源流量不稳定、容易泄漏和污染环境等问题,而且模拟窜气的控制精度约为1%.在选定的试验条件下,DWY-I型低温油泥试验仪能有效地区分不同级别油品的分散性,试验的平行性和重复性都相当好,并与MS程序VD台架试验具有良好的相关性 相似文献