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971.
Long Tang Liang Bai Yaping Duan Wei Xia Wenwen Dong Dongsheng Li 《无机化学与普通化学杂志》2014,640(11):2268-2273
Three ZnII and CdII complexes with Y‐shaped dicarboxylate ligands, namely [Zn(L1)(2,2′‐bpy)2(H2O)] · 2H2O ( 1 ), [Zn(L1)(bpp)(H2O)] ( 2 ), and [Cd(L1)(H2O)] · H2O ( 3 ) [H2L1 = N‐phenyliminodiacetic acid, 2,2′‐bpy = 2,2′‐bipyridine, bpp = 1,3‐bis(4‐pyridyl)propane] were synthesized and characterized by elemental analysis, IR spectroscopy single‐crystal X‐ray diffraction, and thermogravimetric analyses. Compound 1 shows an hydrogen‐bonded 2D network, whereas compound 2 is an infinite 1D wavy chain structure, though O–H ··· O hydrogen‐bonded to form a 2D network. Compound 3 displays a 2D uninodal 3‐connected Shubnikov plane net with the point symbol of (4.82). Moreover, the solid‐state such as thermal stabilities and fluorescence properties of 1 – 3 were also investigated. 相似文献
972.
Jian‐Hua Zou Da‐Liang Zhu Fei‐Fei Li Fu‐Song Li He Wu Qiao‐Yun Li Gao‐Wen Yang Ping Zhang Yun‐Xia Miao Jian Xie 《无机化学与普通化学杂志》2014,640(11):2226-2231
Reactions of three tetrazole containing carboxylic acid ligands, namely, Hpztza, Htzpya, and Hpytza [Hpztza = 5‐(2‐pyrazinyl)tetrazole‐2‐acetic acid, Htzpya = 3‐(5‐tetrazolyl)pyridine‐1‐acetic acid, Hpytza = 5‐(3‐pyridyl)tetrazole‐2‐acetic acid] with NdCl3 · 6H2O under hydrothermal conditions, afforded the complexes [Nd(pztza)2(H2O)6] · pztza · 3H2O ( 1 ), [Nd2(tzpya)2(H2O)12]Cl4 · 2H2O ( 2 ), and [Nd(pytza)2Cl(H2O)2] ( 3 ). The compounds were structurally characterized by elemental analysis, IR spectroscopy and single‐crystal X‐ray diffraction. X‐ray diffraction analyses revealed that compound 1 displays a mononuclear structure, 2 shows a dinuclear structure, and 3 features a 1D polymeric chain structure via pytza as linker. Furthermore, the luminescent properties investigated at room temperature in the solid state show that compound 2 has an obvious decrease in its luminescence, when compared to the ligand. 相似文献
973.
974.
975.
Tomoki Yoneda Young Mo Sung Jong Min Lim Dongho Kim Atsuhiro Osuka 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(48):13385-13389
Reductive metalation of [44]decaphyrin with [Pd2(dba)3] provided a Hückel aromatic [46]decaphyrin PdII complex, which was readily oxidized upon treatment with DDQ to produce a Hückel antiaromatic [44]decaphyrin PdII complex. In CH2Cl2 solution the latter complex underwent slow tautomerization to a Möbius aromatic [44]decaphyrin PdII complex which exists as a mixture of conformers in dynamic equilibrium. To the best of our knowledge, these three PdII complexes represent the largest Hückel aromatic, Hückel antiaromatic, and Möbius aromatic complexes to date. 相似文献
976.
Enhancement of enantioselectivity in chiral capillary electrophoresis using hydroxypropyl‐beta‐cyclodextrin as chiral selector under molecular crowding conditions induced by dextran or dextrin 下载免费PDF全文
Molecular crowding is a new approach to enhance the retention properties and selectivity of molecularly imprinted polymers. In this work, this concept was first applied to chiral CE to enhance its enantioselectivity. A model system, enantioseparation of salbutamol using hydroxypropyl‐beta‐cyclodextrin as chiral selector in the presence of dextran or dextrin as crowding‐inducing agents, was chosen to demonstrate its potency. Some parameters, especially the concentration of crowding‐inducing agents and cyclodextrins were investigated intensively. Moreover, based on fluorescence spectroscopy and affinity CE, it was found that the presence of crowding‐inducing agents could promote the association of enantiomers with cyclodextrins and intensify the interacting differences of two enantiomers with cyclodextrins. As a result, the essential concentration of cyclodextrins to make the enantiomers reach baseline separation was significantly decreased with the aid of molecular crowding. This study shows that molecular crowding is an effective strategy to enhance the enantioselectivity of cyclodextrin in chiral CE. 相似文献
977.
A simple fabrication method for tapered capillary tip and its applications in high‐speed CE and ESI‐MS 下载免费PDF全文
Yong‐Qiang Cheng Yuan Su Xiao‐Xia Fang Jian‐Zhang Pan Qun Fang 《Electrophoresis》2014,35(10):1484-1488
Fabrication of capillaries with tapered tips is an important technique that is required in many analytical chemistry areas, such as ESI‐MS, CE, electrochemical analysis, and microinjection. This paper describes a simple and effective grinding‐based fabrication method for capillaries with tapered tips. A novel grinding mode utilizing the combination of rotation and precession of an elastic capillary was developed, which significantly improved the controllability to the grinding process as well as the capillary tip shape. The capillary was fabricated by fixing it in an electric drill installed perpendicularly, and grind the capillary tip rotated around its own axis as well as the drill axis on sandpapers. Compared with conventional fabrication techniques for capillary tips, the present method is easy to control the capillary tip shape in routine laboratories without the requirement of expensive equipments or poisonous reagent (e.g. hydrofluoric acid (HF) solution). Various capillaries with different tip diameters and tip taper angles could be fabricated using the present method with good controllability and reproducibility. These capillaries were applied in high‐speed CE and ESI‐MS analysis to demonstrate the feasibility and potential of this fabrication method. 相似文献
978.
Jian-Jun Tang Li Zhang Li-Ping Jiang Lei Di Yong-Ming Yan Zheng-Chao Tu Cui-Ping Yang Zhi-Li Zuo Bo Hou Hou-Lin Xia Yong-Bin Chen Yong-Xian Cheng 《Tetrahedron》2014
Polyrhachis dives is consumed as an insect food in some regions of China. In this study, new dopamine derivatives, (+)-polyrhadopamine A (1a) and (−)-polyrhadopamine A (1b), (+)-polyrhadopamine B (2a) and (−)-polyrhadopamine B (2b), and polyrhadopamines C–E (3–5), were isolated from this species. The structures and stereochemistry of these substances were assigned by using spectroscopic and computational methods. Compounds 1a, 1b, 2a, and 2b are dimeric N-acetyldopamine derivatives, 3 is a dopamine analog containing an unusual sulfone group, and 4 and 5 possess a rare benzo[d]thiazole moiety. The functions of these substances as ROCK1/2 inhibitors, neural stem cell (NSCs) proliferation stimulators, immunosuppressive, and anti-inflammatory agents were determined. 相似文献
979.
A novel and direct cross-dehydrogenative coupling (CDC) between benzimidazoles with aldehydes promoted by di-tert-butyl peroxide (DTBP) was developed. The reactions generated the corresponding N-acylbenzimidazoles in good yields under metal-free conditions. This method has broad substrate scope and high efficiency. 相似文献
980.
Nickel(I) complexes were generated in situ from Ni (PPh3)2Cl2 using activated iron and the complexes combined with N,N′-bis(4-fluorobenzylidene) ethane-1,2-diamine (BFBED) were then used as a catalyst for the 1,4-addition reaction of arylboronic acids to α,β-unsaturated substrates. The reaction proceeded to completion and did not require the addition of a base but the addition of potassium iodide is crucial to this cross-coupling reaction. Moreover, experimental observations suggested a possible Ni(I)–Ni(III) catalytic cycle mechanism. 相似文献