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Aida Contreras-Ramirez Dr. Bryan E. Tomlin Gregory S. Day Prof. Dr. Abraham Clearfield Prof. Dr. Hong-Cai Zhou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(28):6185-6194
Nanosized α-zirconium phenylphosphonate particles were successfully prepared by the reaction between different zirconium sources and molten phenylphosphonic acid in the absence of solvent. The resultant nanoplates exhibit particle sizes in the range of 15 to 30 nm. The use of a topotactic anion exchange method starting from α-zirconium phosphate instead resulted in the generation of 15 to 180 nm plates, while also resulting in nanoparticles with a higher degree of crystallinity. The topotactic anion exchange of the phosphate groups by phenylphosphonate groups could be performed to completion when performed in molten phenylphosphonic acid. Characterization of both the final products as well as the individual steps in the anion exchange were performed by powder XRD, fast neutron activation analysis, TGA, FTIR spectroscopy, TEM, solid-state NMR and XPS. 相似文献
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Vladimir I. Bakhmutov Aida Contreras-Ramirez Hannah Drake Hong-Cai Zhou 《Magnetic resonance in chemistry : MRC》2022,60(6):541-553
Solid-state NMR experiments on 2H, 31P, 13C, and 1H nuclei, including 31P T1, 1H T1, and 1H T1ρ measurements, as well as on the kinetics of proton-phosphorus cross-polarization have been performed to characterize the crystalline and amorphous α-zirconium phosphates, which were intercalated with D2O and/or CD3OD. The 13C{1H} CP MAS NMR experiment performed for compound 1-CD 3 OD (Zr (HPO4)2 . 0.2CD3OD) with carbon cross-polarization via protons of phosphate groups has provided a prove that the methanol was intercalated into the interlayer spaces of this compound. The variable-temperature 2H solid-echo MAS NMR spectra of intercalated compounds demonstrated that the methanol molecules, in contrast to the mobile water, were immobile, keeping, however, free CD3 rotations around the C3-axis. It has been demonstrated that the intercalated species, D2O and CD3OD, do not affect the high-frequency motions of the phosphate groups. By utilizing local structural models that satisfy the constraints of the experimental data, it has been suggested that the immobile methanol molecules are located in the cavity between two neighboring layers of the zirconium phosphates. Thus, the present work illustrates the reliable criteria in a comprehensive NMR approach to structural and dynamic studies of such systems. 相似文献
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Yi-Xiang Shi Huan-Huan Chen Prof. Wen-Hua Zhang Gregory S. Day Prof. Jian-Ping Lang Prof. Hong-Cai Zhou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(36):8543-8549
The photoinduced dynamic behavior of flexible materials has received considerable attention for potential applications, such as in data storage or as smart optical devices and molecular mechanical actuators. Until now, precisely controlling expansion and contraction with light has remained a challenge. Unraveling the detailed mechanisms of photoinduced structural transformations remains a critical step necessary to understand the molecular architecture necessary for the design of sensitive photomechanical actuators. Herein, a two-dimensional flexible metal–organic framework [Zn2(bdc)2(3-CH3-spy)2]⋅H2O ( Zn2-1 ; H2bdc=1,4-benzenedicaboxylic acid; 3-CH3-spy=3-methylstyrylpyridine) with a positive volumetric thermal expansion coefficient of +78.78×10−6 K−1 is reported. Upon light irradiation at different wavelengths, the MOF underwent a [2+2] cycloaddition, which afforded a family of isomeric, three-dimensional MOFs ( Zn2-2 n , n=a–d) in a single-crystal-to-single-crystal (SCSC) manner. An unprecedented phenomenon, that is, photoinduced nonlinear contraction (PINC), was observed during this conversion. The PINC is caused by conformational changes in the 3-CH3-spy and bdc2− ligands, the bending of metal–ligand bonds, and the local distortion of the paddle-wheel SBUs. The formation of a “wrinkle morphology” on the crystal surface after the photoreaction was observed by AFM. This PINC behavior can broaden the studies on materials expansion and offer a photodriven approach for the future design of supersensitive photomechanical actuators. 相似文献
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The extent to which drugs combine with trypsin is influenced by the interaction of tartrazine and trypsin, which may cause overdose or underdose of drugs. Therefore, the interaction of tartrazine and trypsin is investigated by methods of spectrometry in this paper. The binding rate of tartrazine to trypsin is 80.95–95.71% at 310?K, and Hill’s coefficients are almost 1. The effect of tartrazine on trypsin structure was studied by synchronous and circular dichroism. The results showed that the binding of tartrazine and trypsin induced the conformational change of trypsin, and quenched the endogenous fluorescence in trypsin. The results of molecular docking revealed that tartrazine is located in the catalytic active site of trypsin, and is consistent with that of experimental calculation. 相似文献
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Jialuo Li Shuai Yuan Jun-Sheng Qin Jiandong Pang Peng Zhang Yingmu Zhang Yanyan Huang Hannah F. Drake Wenshe R. Liu Prof. Dr. Hong-Cai Zhou 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(24):9405-9409
The controlled synthesis of multicomponent metal–organic frameworks (MOFs) allows for the precise placement of multiple cooperative functional groups within a framework, leading to emergent synergistic effects. Herein, we demonstrate that turn-on fluorescence sensors can be assembled by combining a fluorophore and a recognition moiety within a complex cavity of a multicomponent MOF. An anthracene-based fluorescent linker and a hemicyanine-containing CN−-responsive linker were sequentially installed into the lattice of PCN-700. The selective binding of CN− to hemicyanine inhibited the energy transfer between the two moieties, resulting in a fluorescence turn-on effect. Taking advantage of the high tunability of the MOF platform, the ratio between anthracene and the hemicyanine moiety could be fine-tuned in order to maximize the sensitivity of the overall framework. The optimized MOF-sensor had a CN−-detection limit of 0.05 μm , which is much lower than traditional CN− fluorescent sensors (about 0.2 μm ). 相似文献
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A simple scheme for the generation of the three-qutrit Λ-type singlet state with resonant interaction via trapped ions is proposed. In the present proposal, the required interaction time is very short due to resonant interaction. The present proposal may be realized based on the current technologies. We also note that the three-ion three-level maximally entangled state can be generated via resonant interaction in one step. 相似文献
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利用高分子支撑法将气相沉积(CVD)石墨烯从铜基底上转移到聚对苯二甲酸乙二醇酯(PET)基底上,制备出石墨烯平面电极(GPE), 通过循环伏安法将铁氰化钴(CoHCF)纳米颗沉积到GPE上,得到铁氰化钴修饰石墨烯平面电极(CoHCF/GPE).研究表明,此电极对过氧化氢具有良好的传感作用,从而构建一种新型无酶过氧化氢传感器.此传感器在过氧化氢浓度为5.0-1200 μmol/L范围内,响应电流与浓度呈现良好的线性关系,检出限为7.1 nmol/L (S/N=3),响应时间约为2 s,具有稳定性好、抗干扰能力强、制备简单等优点. 相似文献
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AbstractThe interaction of pioglitazone hydrochloride bound to tryptophan residues and tyrosine residues in bovine transferrin was investigated using synchronous fluorescence spectroscopy at various temperatures (298, 310, and 318?K). From binding constants and thermodynamic parameters, it was shown that 1:1 stable compound was formed by the electrostatic force interaction of pioglitazone hydrochloride bound to tryptophan residues and tyrosine residues in bovine transferrin. The extent of binding between pioglitazone hydrochloride and tryptophan residues in bovine transferrin was more than that between pioglitazone hydrochloride and tyrosine residues in bovine transferrin. At 310?K, the fluorescence quenching ratio number of tyrosine residues and tryptophan residues in bovine transferrin were 47.52% and 54.19%, respectively, which indicated that the fluorescence contribution of tryptophan residues was greater. At 310?K, pioglitazone hydrochloride-tyrosine residues(in bovine transferrin) binding rate were 55.60–73.82%, and the combined model was W?=??0.0315R2???0.1520R?+?0.7385. The value of Hill’s coefficients was greater than 1, which suggested that there was a positive cooperativity between pioglitazone hydrochloride and subsequent ligands. The results of molecular docking were consistent with that of experimental calculation. 相似文献