The title compound, penta-iron tripraseodymium dodeca-oxide (PrIG), has an iron garnet structure. There are two Fe site symmetries. One of the Fe atoms is coordinated by six O atoms, forming a slightly distorted octa-hedron, and has site symmetry. The other Fe atom is coordinated by four O atoms, forming a slightly distorted tetra-hedron, and has site symmetry. FeO(6) octa-hedra and FeO(4) tetra-hedra are linked together by corners. The Pr atom is coordinated by eight O atoms, forming a distorted dodeca-hedron, and has 222 site symmetry. The O atoms occupy the general positions.
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http://dx.doi.org/10.1107/S1600536809038100 | DOI Listing |
Chemphyschem
January 2025
Shanxi University, Institute of Molecular Science, CHINA.
Delocalized multicenter bonds play a crucial role in clusters with a planar hypercoordinate center(s), making it difficult for highly electronegative elements, especially halogen atoms, to achieve the planar hypercoordinate arrangement. Herein, we introduce a star-like cluster Br6Li5-, whose global minimum contains a planar pentacoordinate bromine (ppBr). In this cluster, the central ppBr atom coordinates with five alkali metal Li atoms, which in turn bridge an equal number of electronegative Br atoms in the periphery, leading to the formation of the binary cluster Br6Li5-.
View Article and Find Full Text PDFMolecules
January 2025
N. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninsky Prosp. 31, 119991 Moscow, Russia.
The interaction of sodium phytate hydrate CHOP·xNa·yHO (phytNa) with Cu(OAc)·HO and 1,10-phenanthroline (phen) led to the anionic tetranuclear complex [Cu(HO)(phen)(phyt)]·2Na·2NH·32HO (), the structure of the latter was determined by X-ray diffraction analysis. The phytate is completely deprotonated; six phosphate fragments (with atoms P1-P6) are characterized by different spatial arrangements relative to the cyclohexane ring (1a5e conformation), which determines two different types of coordination to the complexing agents-P1 and P3, P4, and P6 have monodentate, while P2 and P5 are bidentately bound to Cu cations. The molecular structure of the anion complex is stabilized by a set of strong intramolecular hydrogen bonds involving coordinated water molecules.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Departamento de Micro y Nanotecnologías, Instituto de Ciencias Aplicadas y Tecnología, Universidad Nacional Autónoma de México, Cto. Exterior S/N, C.U., Coyoacán, Ciudad de México C.P. 04510, Mexico.
Thermus thermophilus HB27 laccase (Tth-Lac) is a thermostable enzyme that contains a β-hairpin (Ala292-Gln307) covering the substrate entrance. We analyzed the role of this β-hairpin in the enzymatic activity of Tth-Lac through three β-hairpin mutants: two variants without the β-hairpin (C1Tth-Lac and C2Tth-Lac) and one with a partially modified β-hairpin (P1Tth-Lac). Enzymatic activity was assayed with different substrates with and without copper.
View Article and Find Full Text PDFJ Environ Sci (China)
July 2025
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address:
Arsenic (As) and antimony (Sb), with analogy structure, belong to VA group in the periodic table and pose a great public concern due to their potential carcinogenicity. The speciation distribution, migration and transformation, enrichment and retention, as well as bioavailability and toxicity of As and Sb are influenced by several environmental processes on mineral surfaces, including adsorption/desorption, coordination/precipitation, and oxidation/reduction. These interfacial reactions are influenced by the crystal facet of minerals with different atomic and electronic structures.
View Article and Find Full Text PDFChemSusChem
January 2025
Sun Yat-Sen University, School of Materials Science and Engineering, No. 135, Xingang Xi Road, China, 510006, Guangzhou, CHINA.
Sluggish oxygen evolution reaction (OER) is a crucial part of water splitting and solar fuel generation, which limits their utilization. Ni3S2 is a promising OER catalyst, in which surface reconstruction is an important step to improve performance. In this study, DFT calculations were employed to investigate the effect of surface reconstruction on (001), (110), and (101) surfaces of Ni3S2 in alkaline OER.
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