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971.
Nikita Barman Saikat Banerjee Paula Brandão Antonio Bauzá 《Journal of Coordination Chemistry》2016,69(7):1188-1205
Four complexes based on N,N′-bis(2-pyridylmethylene)-1,3-propanediamine (L) and different Cd(II) salts have been synthesized and characterized by single-crystal X-ray diffraction analysis. The complexes are [Cd2(L)2(μ-Cl)2](ClO4)2 (1), [Cd2(L)2(μ-Br)2](ClO4)2 (2), [Cd(L)I](ClO4) (3), and [Cd(L)(NCS)2] (4). L exhibits the same coordination mode in 1–4. The radius of each anion plays a role in affecting the structures and luminescent intensities of the final products. CdCl2, CdBr2, and CdI2 react with L to produce chloride or bromido-bridged binuclear complexes and mononuclear iodido complex, respectively, whereas an unusual mononuclear trigonal prismatic (TP) 4 is obtained when thiocyanate was used as a coligand. Photoluminescence properties of all the complexes show that the trend of fluorescence intensity is 1 > 4 > 2 > 3. All four complexes exhibit different supramolecular interactions such as C–H/σ, π–π, and C–H/π and hydrogen bonding interactions. The experimental findings are complemented by density functional theory (DFT) calculations. 相似文献
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Direct Structural Identification of Gas Induced Gate‐Opening Coupled with Commensurate Adsorption in a Microporous Metal–Organic Framework 下载免费PDF全文
Dr. Debasis Banerjee Hao Wang Dr. Anna M. Plonka Dr. Thomas J. Emge Dr. John B. Parise Prof. Dr. Jing Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(33):11816-11825
Gate‐opening is a unique and interesting phenomenon commonly observed in flexible porous frameworks, where the pore characteristics and/or crystal structures change in response to external stimuli such as adding or removing guest molecules. For gate‐opening that is induced by gas adsorption, the pore‐opening pressure often varies for different adsorbate molecules and, thus, can be applied to selectively separate a gas mixture. The detailed understanding of this phenomenon is of fundamental importance to the design of industrially applicable gas‐selective sorbents, which remains under investigated due to the lack of direct structural evidence for such systems. We report a mechanistic study of gas‐induced gate‐opening process of a microporous metal–organic framework, [Mn(ina)2] (ina=isonicotinate) associated with commensurate adsorption, by a combination of several analytical techniques including single crystal X‐ray diffraction, in situ powder X‐ray diffraction coupled with differential scanning calorimetry (XRD‐DSC), and gas adsorption–desorption methods. Our study reveals that the pronounced and reversible gate opening/closing phenomena observed in [Mn(ina)2] are coupled with a structural transition that involves rotation of the organic linker molecules as a result of interaction of the framework with adsorbed gas molecules including carbon dioxide and propane. The onset pressure to open the gate correlates with the extent of such interaction. 相似文献
975.
Dr. Markus Ruetz Aranganathan Shanmuganathan Dr. Carmen Gherasim Agnes Karasik Dr. Robert Salchner M. Sc. Christoph Kieninger Dr. Klaus Wurst Prof. Ruma Banerjee Prof. Markos Koutmos Prof. Bernhard Kräutler 《Angewandte Chemie (International ed. in English)》2017,56(26):7387-7392
B12 antivitamins are important and robust tools for investigating the biological roles of vitamin B12. Here, the potential antivitamin B12 2,4-difluorophenylethynylcobalamin (F2PhEtyCbl) was prepared, and its 3D structure was studied in solution and in the crystal. Chemically inert F2PhEtyCbl resisted thermolysis of its Co−C bond at 100 °C, was stable in bright daylight, and also remained intact upon prolonged storage in aqueous solution at room temperature. It binds to the human B12-processing enzyme CblC with high affinity (KD=130 nm ) in the presence of the cosubstrate glutathione (GSH). F2PhEtyCbl withstood tailoring by CblC, and it also stabilized the ternary complex with GSH. The crystal structure of this inactivated assembly provides first insight into the binding interactions between an antivitamin B12 and CblC, as well as into the organization of GSH and a base-off cobalamin in the active site of this enzyme. 相似文献
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Satyabrata Sahu D. K. Banerjee 《International journal of environmental analytical chemistry》2013,93(1-4):35-44
Abstract Potentiometric titration with ion-selective electrodes was applied to determine characteristic parameters like the degree of complexation and the approximate molecular weight of humic acids from theoretical considerations and conditional stability constants for the complexes of Cu(II) and Cd(II) with humic acids obtained from sources such as garden soil, peat prepared by decomposing water hyacinth in soil and humified water hyacinth. Double-reciprocal and Scatchard plots were constructed to determine the conditional stability constants of the complexes formed. Cu(II) was found to have more affinity for the humic acids than Cd(II) and the stability of the metal complexes in aqueous medium was found to increase with increasing pH. The order of stability of the complexes was M-HA (soil)>M-HA (peat)>M-HA (humified water hyacinth), where M and HA represent metal and humic acids, respectively. 相似文献
979.
Two hexanuclear zinc(II) complexes, [Zn6(L1)2(μ2-OH)2(μ2-CH3COO)8] · CH3CN (1 · CH3CN) and [Zn6(L2)2(μ2-OH)2(μ2-CH3COO)8] · 4CH3CN (2 · 4CH3CN), where HL1 = 4-methyl-2,6-bis(cyclohexylmethyliminomethyl)-phenol and HL2 = 4-methyl-2,6-bis(1-naphthalylmethyliminomethyl)-phenol, have been synthesized and characterized by elemental analysis, FT-IR and fluorescence spectroscopic methods, and by X-ray diffraction analysis. In the asymmetric unit of complex 1, two of the three zinc atoms have pentacoordinate geometries and the other is tetrahedrally coordinated, whereas the three distinct Zn atoms in complex 2 adopt three different coordination environments, namely distorted octahedral, trigonal bipyramidal and tetrahedral. The fluorescence properties of the ligands and complexes have been investigated. 相似文献