The ε-Keggin [AlO4Al12(OH)24(H2O)12](7+) ion (AlAl12(7+)) is a metastable precursor in the formation of aluminum oxyhydroxide solids. It also serves as a useful model for the chemistry of aluminous mineral surfaces. Herein we calculate the enthalpies of formation for this aqueous ion and its heterometal-substituted forms, GaAl12(7+) and GeAl12(8+), using solution calorimetry. Rather than measuring the enthalpies of the MAl12(7/8+) ions directly from solution hydrolysis, we measured the metathesis reaction of the crystallized forms with barium chloride creating an aqueous aluminum solution monospecific in MAl12(7/8+). Then, the contributions to the heat of formation from the crystallized forms were subtracted using referenced states. When comparing the aqueous AlAl12(7+) ion to solid aluminum (oxy)-hydroxide phases, we found that this ion lies closer in energy to solid phases than to aqueous aluminum monomers, thus explaining its role as a precursor to amorphous aluminum hydroxide phases.
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http://dx.doi.org/10.1002/anie.201503544 | DOI Listing |
J Orthop Surg Res
January 2025
Xuzhou Medical University Affiliated Stomatology Hospital, Xuzhou, 221002, Jiangsu Province, China.
Purpose: We aimed to explore the mechanism by which Boron-doped nano-hydroxyapatite (B-nHAp) facilitates the proliferation and differentiation of osteoblasts through controlled release of B.
Methods: B-nHAp characterization was accomplished by means of X-ray diffraction, scanning electron microscopy, inductively coupled plasma mass spectrometry, and transmission electron microscopy. Human bone marrow mesenchymal stem cells (hBMSCs) were subjected to flow cytometry, alizarin red S staining, and cell counting kit-8 assay for proliferation and differentiation determination.
J Phys Chem A
January 2025
Novosibirsk State University, Pirogov str. 1, Novosibirsk 630090, Russian Federation.
Nine metal complexes formed by three symmetric β-diketonates (, acetylacetonate (), 1,1,1,3,3,3-hexafluoro-acetylacetonate (), and 2,2,6,6-tetramethylheptane-3,5-dionate ()) and three metal ions (with three different coordination geometries, , Be - tetrahedral, Cu - square planar, and Pb - "swing" square pyramidal) were investigated. The study combines structural analyses, vibrational spectroscopic techniques, and quantum chemical calculations with the aim of bridging crystal structure, electronic structure, molecular topology, and far-infrared (FIR) spectroscopic characteristics. The effect of intramolecular interactions on the structural, electronic, and spectroscopic features is the center of this study.
View Article and Find Full Text PDFBiochem Biophys Res Commun
January 2025
San Francisco State University, Department of Chemistry and Biochemistry, San Francisco, CA, 94132, USA. Electronic address:
Enterococcus faecalis is a multi-drug-resistant human pathogen that is found in a variety of environments and is challenging to treat. Under stress conditions, some bacteria regulate intracellular polyamine concentrations via polyamine acetyltransferases to reduce their toxicity. The E.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Key Laboratory of Green Printing, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
Colloidal crystal engineering enables the precise construction of structures with remarkable properties. However, the flexible and synergistic regulation of multiple properties of colloidal crystals remains a significant challenge. Here, we inspire from Brazilian opals to self-assemble polymer nanoparticles in the gaps of a single-layer opal substrate to fabricate large-scale binary colloidal crystals (BCCs).
View Article and Find Full Text PDFChemistry
January 2025
Universite Claude Bernard Lyon 1, ICBMS, Bâtiment Lederer, 1 Rue Victor Grignard, F-69622, Villeurbanne, FRANCE.
In this article we describe research on the synthesis and characterization of a family of "Janus" amphiphiles composed of disaccharide head groups and alkaloid units joined together via a methylene linker, and bearing a lateral aliphatic chain of varying length. The condensed phases formed by self-organization of the products as a function of temperature were characterized by differential scanning calorimetry, thermal polarized light microscopy, and small angle X-ray scattering, allied with computational modelling and simulations. Structural studies on heating specimens from the solid showed that some homologues exhibited lamellar, columnar and bicontinuous mesophases, whereas the same homologues revealed different phase sequences on cooling from the amorphous liquid.
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