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921.
Youxin Yao Wenju Zeng Bin Zhang Yunqi Liu Daoben Zhu 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(3):e90-e91
The title complex, C14H20O4S8+.BF4?, is a charge‐transfer complex with typical charges for the donor and anion of +1 and ?1, respectively. Two centrosymmetrically related donors form a face‐to‐face π‐dimer with a strong intermolecular S?S interaction. These π‐dimers stack along the a axis to form a donor column. The structure is extensively hydrogen bonded. 相似文献
922.
A new water-soluble oligo(phenylenevinylene) containing a tyrosine unit (OPV-Tyr) was synthesized as a fluorescent probe to optically detect tyrosinase activity. Upon the addition of tyrosinase, the tyrosine moiety was oxidized to quinone, which quenched the fluorescence of OPV-Tyr via intramolecular electron transfer from the phenylenevinylene unit to the quinone site. OPV-Tyr was elaborated to detect tyrosinase activity both in aqueous buffer solution and in agarose gel. 相似文献
923.
924.
On the basis of the reactions of camphor-derived sulfur ylide with alpha-ylidene-beta-diketones, highly efficient and selective synthesis of optically active dihydrofurans has been achieved. 相似文献
925.
The electronic structure, vibrational properties, absorption spectra, and thermodynamic properties of crystalline ammonium perchlorate (AP) and ammonium dinitramide (ADN) have been comparatively studied using density functional theory in the local density approximation. The results shows that the p states for the two solids play a very important role in their chemical reaction. From the low frequency to high frequency region, ADN has more motion modes for the vibrational frequencies than AP. The absorption spectra of AP and ADN display a few, strong bands in the fundamental absorption region. The thermodynamic properties show that ADN is easier to decompose than AP as the temperature increases. 相似文献
926.
A new category of dinucleating macrocyclic Schiff base ligands with ring sizes from 34- to 52-membered have been synthesised employing metal template procedures involving the reaction of o-phenylenediamine with a series of α,ω-bis(3′-hydroxy-4′-formylphenyloxy)alkanes in the presence of calcium(II), barium(II) or manganese(II). The latter cations act as ‘transient’ templates for formation of the corresponding metal-free Schiff base macrocyclic ligands, H4Ln (where n signifies the number of carbons in each linking bis-alkoxy chain); the macrocycles corresponding to n = 4, 6 and 8 were isolated and characterised while, for n = 1, in which single methylene groups acts as the bridges between salicyl moieties, the cyclic product was used directly for preparation of its dinuclear complex, [Zn2L1], without prior isolation. Evidence for the templating role of barium in the preparation of H4L6 and H4L8 was obtained by isolation of the corresponding species of type H4Ln·2Ba(ClO4)2 (n = 6 or 8) as ‘intermediates’ before generation of the respective metal-free macrocycles. Reaction of zinc(II) acetate with the free macrocycles in methanol yielded complexes of type [Zn2Ln] in all cases. A related non-cyclic ligand, H2L0 and its corresponding mononuclear complex, [ZnL0]·H2O, were also synthesised and its spectral properties compared with those of the macrocyclic derivatives. The elemental analyses, 1H NMR, IR, UV–Vis and MS spectra of the respective zinc complexes in each case were in accord with the formation of the expected 2:2 condensation product. The results of DFT calculations to probe aspects of the electronic and structural natures of both H2L1 and H4L4 are briefly presented. 相似文献
927.
Dr. Yutao Sang Dr. Qirong Zhu Dr. Xiaoqin Zhou Dr. Yuqian Jiang Prof. Li Zhang Prof. Minghua Liu 《Angewandte Chemie (International ed. in English)》2023,62(8):e202215867
Herein we describe the self-assembly of an achiral molecule into macroscopic helicity as well as the emergent chiral-selective spin-filtering effect. It was found that a benzene-1,3,5-tricarboxamide (BTA) motif with an aminopyridine group in each arm could coordinate with AgI and self-assemble into nanospheres. Upon sonication, symmetry breaking occurred and the nanospheres transferred into helical nanofibers with strong CD signals. Although the sign of the CD signals appeared randomly, it could be controlled by using the as-made chiral assemblies as a seed. Furthermore, it was found that the charge transport of the helical nanofibers was highly selective with a spin-polarization transport of up to 45 %, although the chiral nanofibers are composed exclusively from achiral building blocks. This work demonstrates symmetry breaking under sonication and the chiral-selective spin-filtering effect. 相似文献
928.
Zejing Xing Xiaodan Gou Prof. Dr. Li-Ping Jiang Prof. Dr. Jun-Jie Zhu Dr. Cheng Ma 《Angewandte Chemie (International ed. in English)》2023,62(39):e202308950
Protein coronas are present extensively at the bio-nano interface due to the natural adsorption of proteins onto nanomaterials in biological fluids. Aside from the robust property of nanoparticles, the dynamics of the protein corona shell largely define their chemical identity by altering interface properties. However, the soft coronas are normally complex and rapidly changing. To real-time monitor the entire formation, we report here a self-regulated electrochemiluminescence (ECL) microscopy based on the interaction of the Ru(bpy)33+ with the nanoparticle surface. Thus, the heterogeneity of the protein corona is in situ observed in single nanoparticle “cores” before and after loading drugs in nanomedicine carriers. The label-free, optical stable and dynamic ECL microscopy minimize misinterpretations caused by the variation of nanoparticle size and polydispersity. Accordingly, the synergetic actions of proteins and nanoparticles properties are uncovered by chemically engineered protein corona. After comparing the protein corona formation kinetics in different complex systems and different nanomedicine carriers, the universality and accuracy of this technique were well demonstrated via the protein corona formation kinetics curves regulated by competitive adsorption of Ru(bpy)33+ and multiple proteins on surface of various carriers. The work is of great significance for studying bio-nano interface in drug delivery and targeted cancer treatment. 相似文献
929.
Dr. Tiancheng Pu Wenhao Zhang Prof. Minghui Zhu 《Angewandte Chemie (International ed. in English)》2023,62(4):e202212278
Strong metal–support interactions (SMSI) represent a classic yet fast-growing area in catalysis research. The SMSI phenomenon results in the encapsulation and stabilization of metal nanoparticles (NPs) with the support material that significantly impacts the catalytic performance through regulation of the interfacial interactions. Engineering SMSI provides a promising approach to steer catalytic performance in various chemical processes, which serves as an effective tool to tackle energy and environmental challenges. Our Minireview covers characterization, theory, catalytic activity, dependence on the catalytic structure and inducing environment of SMSI phenomena. By providing an overview and outlook on the cutting-edge techniques in this multidisciplinary research field, we not only want to provide insights into the further exploitation of SMSI in catalysis, but we also hope to inspire rational designs and characterization in the broad field of material science and physical chemistry. 相似文献
930.