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1.
Heliyon ; 10(10): e31219, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38807897

RESUMO

New calcium borovanadate glass containing manganese ions within the system x Mn2O3-(30-x) V2O5-50 B2O3-20 CaO has been elaborated* in this work using melt quench process. The primary objective of this research is to examine the influence of introducing Mn2O3 upon the various properties of the elaborated glass specimens including physical, thermal, structural, optical and magnetic properties. X-ray diffraction indicated that the samples prepared were amorphous. The variation in density and molar volume revealed that the structure of the glass matrix cross-links and becomes more compact with increasing Mn2O3 content, which is confirmed when the glass transition temperature is increased. Furthermore, in order to check the group constitution of our glasses, a structural study was carried out using infrared (FTIR) and Raman spectroscopy. The optical characteristics of our vitreous materials were analyzed by UV solid, and the results of the band gap energy and refractive index values revealed an enhancement of non-bridging oxygen atoms (NBOs) with rising Mn2O3 concentration, also suggests that manganese acts as a structure modifier. The low Urbach energy values are an indication that the structure of our glasses is stable and uniform. The magnetic investigation highlighted the presence of the predominant antiferromagnetic order in the glass samples studied, which becomes stronger with the incorporation of more manganese ions into the structure.

2.
Materials (Basel) ; 17(5)2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38473501

RESUMO

In this study, a chemical precipitation approach was adopted to produce a photocatalyst based on bismuth tungstate Bi2WO6 for enhanced and environmentally friendly organic pollutant degradation. Various tools such as X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), optical spectroscopy and X-ray photoelectron spectroscopy, were employed to assess the structural and morphological properties. Hence, the XRD profiles showed a well crystallized Bi2WO6 orthorhombic phase. The photocatalytic performance of the resulting photocatalyst was assessed by the decomposition of Rhodamine B (RhB) and methyl orange (MO) with a decomposition efficiency of 97 and 92%, along with the highest chemical oxygen demand of 82 and 79% during 120 min of illumination, respectively. The principal novelty of the present work is to focus on the changes in the crystalline structure, the morphology, and the optical and the photoelectrochemical characteristics of the Bi2WO6, by tuning the annealing temperature of the designed photocatalyst. Such physicochemical property changes in the as-prepared photocatalyst will affect in turn its photocatalytic activity toward the organic pollutant decomposition. The photocatalytic mechanism was elaborated based on electrochemical impedance spectroscopy, photocurrent analysis, photoluminescence spectroscopy, and radical trapping measurements. The overall data indicate that the superoxide O2•- and holes h+ are the principal species responsible for the pollutant photodegradation.

3.
J Biomol Struct Dyn ; 38(12): 3578-3586, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31476977

RESUMO

6-Methyl-7H,8H,9H-[1,2,4]triazolo[4,3-b][1,2,4]triazepin-8-onehas been synthesized, characterized by spectroscopic techniques (FT-IR, 1H and 13C NMR) and finally the structure was confirmed by single crystal X-ray diffraction studies. In the title molecule, C6H7N5O, the 7-membered ring adopts a bowl-like conformation. In the crystal, the molecules form stacks along the c-axis direction through offset π-stacking interactions between the 5-membered rings and C-H···N hydrogen bonds. The stacks are associated via a combination of N-H···N, C-H···O and C-H···N hydrogen bonds. Further, the Hirshfeld surface analysis reveals the nature of molecular interactions and the fingerprint plot provides information about the percentage contribution from each individual molecular contact to the surface. In addition, due to its biological interest the target molecule adenosine A1 receptor was found based on Structural Activity Relationship (SAR) analysis and, further, subjected into molecular docking and molecular dynamics analysis to understand the binding interaction and stability of the molecule in adenosine A1 receptor system. Furthermore, the Density Functional Theory (DFT) calculations were carried for free compound and the compound in active site (single point DFT), to know the internal stability.Communicated by Ramaswamy H. Sarma.


Assuntos
Antagonistas do Receptor A1 de Adenosina/química , Simulação de Dinâmica Molecular , Receptor A1 de Adenosina , Cristalografia por Raios X , Simulação de Acoplamento Molecular , Espectroscopia de Infravermelho com Transformada de Fourier
4.
Acta Crystallogr E Crystallogr Commun ; 75(Pt 12): 1919-1924, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31871758

RESUMO

In the title mol-ecule, C13H16N4O3, the mean planes of the phenyl and triazole rings are nearly perpendicular to one another as a result of the intra-molecular C-H⋯O and C-H⋯π(ring) inter-actions. In the crystal, layers parallel to (101) are generated by O-H⋯N, N-H⋯O and N-H⋯N hydrogen bonds. The layers are connected by inversion-related pairs of C-H⋯O hydrogen bonds. The experimental mol-ecular structure is close to the gas-phase geometry-optimized structure calculated by DFT methods. Hirshfeld surface analysis indicates that the most important inter-action involving hydrogen in the title compound is the H⋯H contact. The contribution of the H⋯O, H⋯N, and H⋯H contacts are 13.6, 16.1, and 54.6%, respectively.

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