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151 results on '"Zeng, Yongfei"'

18. Highly Active Pd-PEPPSI Complexes for Suzuki-Miyaura Cross-coupling of Aryl Chlorides: an Investigation on the Effect of Electronic Properties

Author

Zhang, Yingying, Han, Fangwai, Zhang, Mengyao, Zhang, Huixin, Li, Ying, Wang, Ru, Zeng, Yongfei, and Liu, Guiyan

Abstract

Three new Pd-pyridine enhanced precatalyst preparation stabilization and initiation(PEPPSI) complexes with halogen groups on the N-heterocyclic carbene and pyridine were prepared. Their structures have been clearly characterized by nuclear magnetic resonance spectroscopy and X-ray single-crystal diffraction. The effects of the electronic properties of halogen groups on the catalytic activity in the Suzuki-Miyaura cross-coupling of aryl chlorides were investigated. These Pd-PEPPSI complexes could catalyze the cross-coupling reaction efficiently with a low catalyst loading(0.05%, molar ratio) at room temperature and the products were obtained in high yields.

Published
2024
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31. Construction of Covalent‐Organic Frameworks (COFs) from Amorphous Covalent Organic Polymers via Linkage Replacement

Author

Zhai, Yufeng, primary, Liu, Guiyan, additional, Jin, Fenchun, additional, Zhang, Yingying, additional, Gong, Xuefang, additional, Miao, Zhuang, additional, Li, Jinheng, additional, Zhang, Mengyao, additional, Cui, Yumeng, additional, Zhang, Lingyan, additional, Liu, Yu, additional, Zhang, Huixin, additional, Zhao, Yanli, additional, and Zeng, Yongfei, additional

Published
2019
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39. PKU-21 : A Novel Layered Germanate Built from Ge-7 and Ge-10 Clusters for CO2 Separation

Author

Liang, Jie, Su, Jie, Peng, Fei, Zeng, Yongfei, Sun, Junliang, Liang, Jie, Su, Jie, Peng, Fei, Zeng, Yongfei, and Sun, Junliang

Abstract

The attractive properties of layered inorganic materials, which make them suitable for numerous applications in chemical industries and life sciences, originated from their crystalline framework structures. Here, we report a new layered germanate PKU-21, which was prepared by the hydrothermal synthesis method using 2-propanolamine (MIPA) as the structure-directing agent. The structure of PKU-21 was determined from synchrotron single-crystal X-ray diffraction and synchrotron powder X-ray diffraction data. It reveals a complicated framework structure containing 18 unique Ge atoms in the asymmetric unit. PKU-21 is the first layered germanate built from both Ge-7 and Ge-10 clusters, following the 3-dimensional germanate PKU-17. The preparation and structure of PKU-21 are discussed in comparison with PKU-17, which provides new insight into the formation mechanism of germanates. Gas sorption experiments indicate that the layered PKU-21 sample exhibits a better CO2 sorption selectivity over N-2 and CH4 at 298K than at 273K, making it a promising candidate for CO2 separation.

Published
2017
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40. Three new Cu(II)-Ln(III) heterometallic coordination polymers constructed from quinolinic acid and nicotinic acid: Synthesis, structures, and magnetic properties

Author

Xue Li, Wang LiFu, Han Songde, Bu Xianhe, Song WeiChao, Zeng YongFei, and Liu Suijun

Subjects
chemistry.chemical_classification, Crystallography, chemistry.chemical_compound, Nicotinic agonist, Ferromagnetism, Chemistry, Stereochemistry, General Chemistry, Polymer, Isostructural, Antiferromagnetic coupling, Quinolinic acid
Abstract

Three new Cu(II)-Ln(III) heterometallic coordination polymers based on two N-heterocyclic carboxylic ligands, {[LnCu(L1)2(L2)(H2O)2]·mH2O}n (Ln = La(1), Nd(2), Gd(3), m = 2 (for 1), 1 (for 2, 3), H2L1 = quinolinic acid, HL2 = nicotinic acid), have been synthesized and characterized. 1 has a two-dimensional (2D) layer structure with a Schlafli symbol of (44.62), while complexes 2 and 3 are isostructural and have three-dimensional (3D) structures with a Schlafli symbol of (3.4.5)2(32.42.52.614.74.83.9)(32.63.7) of 3-nodal net. Magnetic investigations suggest that antiferromagnetic coupling exists between NdIII and CuII in 2, while weak ferromagnetic coupling between GdIII and CuII in 3. The difference of magnetic properties between 2 and 3 has been discussed.

Published
2012

41. Construction of a Three-dimensional Covalent Organic Framework viathe Linker Exchange Strategy

Author

Cui, Yumeng, Miao, Zhuang, Liu, Qi, Jin, Fenchun, Zhai, Yufeng, Zhang, Lingyan, Wang, Wenli, Wang, Ke, Liu, Guiyan, and Zeng, Yongfei

Abstract

Covalent organic framework(COF) is a porous crystalline material with a well-controlled structure and a wide range of potential applications. However, the construction of new COF faces huge challenges, including the design and synthesis of structural unit monomers, the choice of reaction solvent system, and the study of reaction time and temperature. So, it’s particularly important to widen the application scope of synthetic methods and further promote the development of COFs. Here, we performed structural transformations in a three-dimensional(3D) COF(COF-300), and Fourier transform infrared spectroscopy(FTIR), power X-ray diffraction analysis(PXRD) and nitrogen adsorption isotherms confirmed the chemical principles and the successful realization of these exchanges. At the same time, we found that the interpenetrating structure in 3D COF can be changed through the conversion of linkers. The structure simulation successfully proved the transformation of COF from five-fold to seven-fold interpenetration. In addition, in order to prove the versatility of this strategy, we used the same method to convert COF-300 into a high crystallinity 3D COF(TJNU-COF-302) that is also seven-fold interpenetrating and has not been reported. This simple strategy not only makes it easy to obtain a 3D COF connected with imines, which greatly promotes the development of COF, but also provides a new way to develop 3D COFs with complex interpenetrating structures.

Published
2021
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44. Engineering a Hollow Nanocontainer Platform with Multifunctional Molecular Machines for Tumor-Targeted Therapy in Vitroand in Vivo

Author

Luo, Zhong, Ding, Xingwei, Hu, Yan, Wu, Shaojue, Xiang, Yang, Zeng, Yongfei, Zhang, Beilu, Yan, Hong, Zhang, Huacheng, Zhu, Liangliang, Liu, Junjie, Li, Jinghua, Cai, Kaiyong, and Zhao, Yanli

Abstract

In order to selectively target malignant cells and eliminate severe side effects of conventional chemotherapy, biocompatible and redox-responsive hollow nanocontainers with tumor specificity were fabricated. The mechanized nanocontainers were achieved by anchoring mechanically interlocked molecules, i.e., [2]rotaxanes, onto the orifices of hollow mesoporous silica nanoparticles viadisulfide bonds as intermediate linkers for intracellular glutathione-triggered drug release. The [2]rotaxane employed was mainly composed of U.S. Food and Drug Administration approved tetraethylene glycol chains, α-cyclodextrin, and folic acid. In this study, folate groups on the mechanized hollow nanocontainers act as both the tumor-targeting agents and stoppers of the [2]rotaxanes. Detailed investigations showed that anticancer drug doxorubicin loaded mechanized nanocontainers could selectively induce the apoptosis and death of tumor cells. The drug-loaded nanocontainers enhanced the targeting capability to tumor tissues in vitroand inhibited the tumor growth with minimal side effects in vivo. The present controlled and targeted drug delivery system paves the way for developing the next generation of nanotherapeutics toward efficient cancer treatment.

Published
2024
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49. PKU-21: A Novel Layered Germanate Built from Ge7 and Ge10 Clusters for CO2 Separation.

Author

Liang, Jie, Su, Jie, Peng, Fei, Zeng, Yongfei, and Sun, Junliang

Subjects
GERMANATE glasses, GERMANIUM spectra, MOLECULAR clusters, SEPARATION of gases, CARBON dioxide adsorption, X-ray diffraction
Abstract

The attractive properties of layered inorganic materials, which make them suitable for numerous applications in chemical industries and life sciences, originated from their crystalline framework structures. Here, we report a new layered germanate PKU-21, which was prepared by the hydrothermal synthesis method using 2-propanolamine (MIPA) as the structure-directing agent. The structure of PKU-21 was determined from synchrotron single-crystal X-ray diffraction and synchrotron powder X-ray diffraction data. It reveals a complicated framework structure containing 18 unique Ge atoms in the asymmetric unit. PKU-21 is the first layered germanate built from both Ge7 and Ge10 clusters, following the 3-dimensional germanate PKU-17. The preparation and structure of PKU-21 are discussed in comparison with PKU-17, which provides new insight into the formation mechanism of germanates. Gas sorption experiments indicate that the layered PKU-21 sample exhibits a better CO2 sorption selectivity over N2 and CH4 at 298 K than at 273 K, making it a promising candidate for CO2 separation. [ABSTRACT FROM AUTHOR]

Published
2017
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