Tutton salt (NH 4 ) 2 Zn(SO 4 ) 2 (H 2 O) 6 : thermostructural, spectroscopic, Hirshfeld surface, and DFT investigations.

Autor: de Oliveira Neto JG; Center for Social Sciences, Health, and Technology, Federal University of Maranhão-UFMA, Imperatriz, MA, 65900-410, Brazil., Viana JR; Center for Social Sciences, Health, and Technology, Federal University of Maranhão-UFMA, Imperatriz, MA, 65900-410, Brazil., Abreu KR; Center for Social Sciences, Health, and Technology, Federal University of Maranhão-UFMA, Imperatriz, MA, 65900-410, Brazil., da Silva LFL; Institute of Criminalistics, Scientific Police of Pará, Marabá, PA, 68507-000, Brazil., Lage MR; Center for Social Sciences, Health, and Technology, Federal University of Maranhão-UFMA, Imperatriz, MA, 65900-410, Brazil. mateus.lage@ufma.br., Stoyanov SR; CanmetENERGY Devon, Natural Resources Canada, 1 Oil Patch Drive, Devon, AB, T9G 1A8, Canada. stanislav.stoyanov@nrcan-rncan.gc.ca., de Sousa FF; Center for Social Sciences, Health, and Technology, Federal University of Maranhão-UFMA, Imperatriz, MA, 65900-410, Brazil.; Institute of Exact and Natural Sciences, Federal University of Pará-UFPA, Belem, PA, 66075-110, Brazil., Lang R; Institute of Science and Technology, Federal University of São Paulo-UNIFESP, São José Dos Campos, SP, 12231-280, Brazil., Dos Santos AO; Center for Social Sciences, Health, and Technology, Federal University of Maranhão-UFMA, Imperatriz, MA, 65900-410, Brazil.
Jazyk: angličtina
Zdroj: Journal of molecular modeling [J Mol Model] 2024 Sep 17; Vol. 30 (10), pp. 339. Date of Electronic Publication: 2024 Sep 17.
DOI: 10.1007/s00894-024-06089-7
Abstrakt: Context: Ammonium Tutton salts have been widely studied in recent years due to their thermostructural properties, which make them promising compounds for application in thermochemical energy storage devices. In this work, a detailed experimental study of the Tutton salt with the formula (NH 4 ) 2 Zn(SO 4 ) 2 (H 2 O) 6 is carried out. Its structural, vibrational, and thermal properties are analyzed and discussed. Powder X-ray diffraction (PXRD) studies confirm that the compound crystallizes in a structure of a Tutton salt, with monoclinic symmetry and P2 1 /a space group. The Hirshfeld surface analysis results indicate that the main contacts stabilizing the material crystal lattice are H···O/O···H, H···H, and O···O. In addition, a typical behavior of an insulating material is confirmed based on the electronic bandgap calculated from the band structure and experimental absorption coefficient. The Raman and infrared spectra calculated using DFT are in a good agreement with the respective experimental spectroscopic results. Thermal analysis in the range from 300 to 773 K reveals one exothermic and several endothermic events that are investigated using PXRD measurements as a function of temperature. With increasing temperature, two new structural phases are identified, one of which is resolved using the Le Bail method. Our findings suggest that the salt (NH 4 ) 2 Zn(SO 4 ) 2 (H 2 O) 6 is a promising thermochemical material suitable for the development of heat storage systems, due to its low dehydration temperature (≈ 330 K), high enthalpy of dehydration (122.43 kJ/mol of H 2 O), and hydration after 24 h.
Methods: Computational studies using Hirshfeld surfaces and void analysis are conducted to identify and quantify the intermolecular contacts occurring in the crystal structure. Furthermore, geometry optimization calculations are performed based on density functional theory (DFT) using the PBE functional and norm-conserving pseudopotentials implemented in the Cambridge Serial Total Energy Package (CASTEP). The primitive unit cell optimization was conducted using the Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithm. The electronic properties of band structure and density of states, and vibrational modes of the optimized crystal lattice are calculated and analyzed.
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Databáze: MEDLINE
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