The crystal structures of two compounds, CuL(2) and LiNCS.HL [HL = 4'-[2-(tosylamino)benzylideneamino]-2,3-benzo-15-crown-5], have been determined from synchrotron powder diffraction data. Both compounds crystallize in the monoclinic space group P2(1)/c and with one molecule in the asymmetric unit. In CuL(2) the four N atoms of two bidentate L ligands coordinate the Cu(II) ion in a distorted tetrahedral geometry with Cu-N distances of 1.98 (5)-2.05 (5) A, while two O atoms from two sulfoxide groups complete the distorted octahedral Cu coordination [Cu-O 2.64 (4), 2.74 (4) A]. In LiNCS.HL, lithium is coordinated by all five ether O atoms with Li-O distances of 2.03 (3)-2.50 (3) A and an N atom from the thiocyanate moiety [Li-N 1.98 (3) A] in a distorted pentagonal pyramidal geometry. Preliminary potentiometric selectivity measurements for ion-selective electrodes (ISEs) based on CuL(2) and ZnL(2) demonstrated significant differences in their selectivity. In order to find a possible reason for this, theoretical calculations at the DFT (B3LYP) level were performed. These calculations used the crystal structures of CuL(2), LiNCS.HL, ZnL(2) and HL as input geometries for the minimum energy optimization in vacuo. The results indicate that in ML(2) complexes (M = Cu, Zn) the electronic structure of the metal ion determines the spatial orientation of benzo-15-crown-5 macrocycles, and their different orientation in CuL(2) and ZnL(2) results in different potentiometric selectivities of ISEs based on these compounds.
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http://dx.doi.org/10.1107/S0108768107003898 | DOI Listing |
JACS Au
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Laboratory of Energy Science and Engineering, Department of Mechanical and Process Engineering, Eidgenössische Technische Hochschule (ETH) Zürich, 8092 Zürich, Switzerland.
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Department of Geological Sciences, Pusan National University, Busan 46241, Korea.
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Center for Advanced Low-Dimension Materials, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Chemistry, Chemical Engineering, Donghua University, Shanghai 201600, China.
Creating simple methods to produce antioxidant nanozymes with clear structure-activity relationships, particularly aiming to improve disinfection and create practical drug formulations for bacterial wound healing, remains a crucial challenge. Herein, we synthesized iron-loaded covalent organic framework nanospheres, which were then controllably transformed into a carbon-based nanozyme with both iron single atoms and iron clusters through simple pyrolysis. We discovered that the gradual growth of iron clusters significantly boosted the nanozyme's adsorption onto the substrate and electron transfer, greatly influencing its activity.
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Departamento de Física Aplicada-Instituto de Ciencia de Materiales, MALTA Consolider Team, Universidad de Valencia, Edificio de Investigación, C/Dr. Moliner 50, Burjassot, 46100 Valencia, Spain.
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View Article and Find Full Text PDFJ Phys Chem A
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National Key Laboratory of Solid Propulsion, School of Astronautics, Northwestern Polytechnical University, Xi'an 710072, China.
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