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51.
Bischler-Napieralski cyclization has been successfully employed to prepare planar S,N-heteroacenes (SNHs) with the analogue structures to 1,10-phenanthroline. The opto-/electrical properties and the packing modes of these S,Nheteroacenes were examined, which were dependent on the structure of the fused groups. SNH-based copolymers with high molecular weight and good solubility in common organic solvents or water have been synthesized by Suzuki-Miyaura- Schlüter polycondensation. The photophysical property studies revealed that the copolymers may be a promising chemosensor material. 相似文献
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修正了以第二类Chebyshev多项式的零点为插值结点组的拟Grünwald插值多项式,使之转化为积分形式,并利用不等式技巧和Hardy-Littlewood极大函数的方法,研究了此积分型拟Grünwald插值算子在带权Orlicz空间内的逼近问题,得出了意义相对广泛的逼近度估计的结果. 相似文献
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Dr. Yang Jiao Lei Zhang Xu Gao Wen Si Prof. Chunying Duan 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(15):6077-6083
Identifying the location and expression levels of enzymes under hypoxic conditions in cancer cells is vital in early-stage cancer diagnosis and monitoring. By encapsulating a fluorescent substrate, L-NO2 , within the NADH mimic-containing metal–organic capsule Zn- MPB , we developed a cofactor-substrate-based supramolecular luminescent probe for ultrafast detection of hypoxia-related enzymes in solution in vitro and in vivo. The host–guest structure fuses the coenzyme and substrate into one supramolecular probe to avoid control by NADH, switching the catalytic process of nitroreductase from a double-substrate mechanism to a single-substrate one. This probe promotes enzyme efficiency by altering the substrate catalytic process and enhances the electron transfer efficiency through an intra-molecular pathway with increased activity. The enzyme content and fluorescence intensity showed a linear relationship and equilibrium was obtained in seconds, showing potential for early tumor diagnosis, biomimetic catalysis, and prodrug activation. 相似文献
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Dr. Yihui Yuan Shiwei Feng Lijuan Feng Qiuhan Yu Tingting Liu Prof. Ning Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(11):4292-4298
Biology has evolved excellent spatial structures for high-selectivity and high-affinity capture of heavy metals. Inspired by the spatial structure of the superb-uranyl binding protein SUP, we mimic the spatial structure of SUP in metal–organic frameworks (MOFs). The MOF UiO-66-3C4N fabricated by introducing 4-aminoisophthalic acid into UiO-66 shows high uranyl adsorption capacity both in simulated seawater and in natural seawater. In natural seawater, UiO-66-3C4N exhibits 17.03 times higher uranium extraction capacity than that of vanadium, indicating the high selectivity of the adsorbent. The EXAFS analysis and DFT calculation reveal that UiO-66-3C4N forms smaller nano-pocket for uranyl capture than that of SUP protein, which can both restrict the entrance of the other interfering ions with larger size and reinforce the binding by increasing the coordination interaction, and therefore qualify the nano-pocket with high affinity and high selectivity to uranyl. 相似文献
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Liangyu Hu Kun Li Weili Shang Dr. Xuefeng Zhu Prof. Minghua Liu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(12):4983-4988
The chiral feature of γCD-MOF, and especially the emergent cubic void, was not unveiled so far. Now, through the host–guest interaction between γCD-MOF and achiral luminophores with different charges and sizes, the unique cubic chirality of the emerging void in γCD-MOF as well as a size effect on CPL induction are revealed for the first time. Numerous achiral luminophores could be integrated into γCD-MOF and emitted significantly boosted circularly polarized luminescence. While the small sized luminophores preferred to be loaded into the intrinsic void of γCD, large ones were selectively encapsulated into the cubic void. Interestingly, when the size of the guest luminophores was close to the cube size, it showed strong negative CPL. Otherwise, either positive or negative CPL was induced. 相似文献
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In‐Hyeok Park Eunji Lee Shim Sung Lee Jagadese J. Vittal 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(42):15002-15006
Conventional chemical patterning involves films of polymeric materials. Herein, we demonstrate that the presence or absence of guest solvents in the crystal voids modulates the patterning of the cyclobutane rings in highly strained metal–organic frameworks (MOFs) under UV light. The olefin pairs of the spacer ligands, which resemble a ladder‐like structure, in the MOF, undergo a [2+2] cycloaddition reaction in a single‐crystal‐to‐single‐crystal manner. For instance, a partial photoreaction in the MOFs in the absence of a guest solvent as well as with dimethylacetamide in the voids generated two different patterns of the cyclobutane rings. Surprisingly, the MOF with the lattice dimethylformamide undergoes 100 % photoreaction, but the photoproduct contains broken chains. Such chemical patterning at the molecular level represents a next step in crystal engineering. 相似文献
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Hongfeng Li Peng Wu Yawen Xiao Meng Shao Yu Shen Yun Fan Huanhuan Chen Ruijie Xie Wenlei Zhang Prof. Sheng Li Prof. Jiansheng Wu Prof. Yu Fu Prof. Bing Zheng Prof. Weina Zhang Prof. Fengwei Huo 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(12):4793-4799
Metal–organic frameworks (MOFs) are promising materials with fascinating properties. Their widespread applications are sometimes hindered by the intrinsic instability of frameworks. However, this instability of MOFs can also be exploited for useful purposes. Herein, we report the use of MOFs as metal ion precursors for constructing functional nanocomposites by utilizing the instability of MOFs. The heterogeneous growth process of nanostructures on substrates involves the release of metal ions, nucleation on substrates, and formation of a covering structure. Specifically, the synthesized CoS with carbon nanotubes as substrates display enhanced performance in a lithium-ion battery. Such strategy not only presents a new way for exploiting the instability of MOFs but also supplies a prospect for designing versatile functional nanocomposites. 相似文献