scholarly journals High-temperature study of basic ferric sulfate, FeOHSO4

2020 ◽  
Vol 47 (10) ◽  
Author(s):  
Gennaro Ventruti ◽  
Giancarlo Della Ventura ◽  
Mario Alberto Gomez ◽  
Giancarlo Capitani ◽  
Marco Sbroscia ◽  
...  
Keyword(s):  
Variable Temperature ◽  
Chemical Study ◽  
Ferric Sulfate ◽  
Hydrogen Atoms ◽  
Selected Area Electron Diffraction ◽  
Linear Chains ◽  
Structure Solution ◽  
Ir And Raman Spectroscopies ◽  
Ir And Raman ◽  
High Temperature Study

Abstract We report in this paper a new crystal-chemical study of synthetic basic ferric sulfate FeOHSO4. The structure solution performed by the Endeavour program, from new X-ray powder diffraction (XRPD) data, indicated that the correct space group of the monoclinic polytype of FeOHSO4 is C2/c. Selected Area Electron Diffraction (SAED) patterns are also consistent with this structure solution. The arrangement of Fe and S atoms, based on linear chains of Fe3+ octahedra cross-linked by SO4 tetrahedra, corresponds to that of the order/disorder (OD) family. The positions of the hydrogen atoms were located based on DFT calculations. IR and Raman spectra are presented and discussed according to this new structure model. The decomposition of FeOHSO4 during heating was further investigated by means of variable temperature XRPD, thermogravimetry, and differential thermal analysis as well as IR and Raman spectroscopies.

scholarly journals Study of the coordination of quinuclidine to a chiral zinc phthalocyanine dimer

2016 ◽  
Vol 20 (08n11) ◽  
pp. 1224-1232 ◽  
Author(s):  
Nelson Giménez-Agulló ◽  
Gemma Aragay ◽  
José Ramón Galán-Mascarós ◽  
Pablo Ballester
Keyword(s):  
Chemical Exchange ◽  
Variable Temperature ◽  
Exchange Process ◽  
Zinc Phthalocyanine ◽  
Hydrogen Atoms ◽  
Dimerization Constant ◽  
H Nmr ◽  
Dimerization Process ◽  
Nmr Titrations ◽  
Millimolar Concentration

We attempted the calculation of an accurate equilibrium constant for the dimerization process of enantiomerically pure Zn-1 using UV-vis dilution experiments. At millimolar concentration Zn-1 is involved in a chemical exchange process between its monomeric and dimeric state that is slow on the 1H NMR timescale. We performed variable-temperature 1H NMR experiments in CDCl3 solution to determine the dimerization constant value at different temperatures and performed a van’t Hoff plot to derive the thermodynamic parameters of the process. The calculated thermodynamic data revealed that the dimerization process is entropy-driven and enthalpically opposed. We also probed the coordination of quinuclidine, 1-azabicyclo[2.2.2]octane, 2, to the Zn-1 using UV-vis and 1H NMR titrations in CDCl3 solution. At micromolar concentration the Zn-1 exclusively exists in solution as a monomer and forms a simple 1:1, [Formula: see text], complex with quinuclidine having a stability constant of [Formula: see text]([Formula: see text]) [Formula: see text] 106 M[Formula: see text]. On the other hand, the 1H NMR titrations carried out at 298 K and at millimolar concentration showed that Zn-1 was present in solution as the dimer and formed 1:2, [Formula: see text], and 2:2, [Formula: see text] complexes by coordination to 2. In addition, the 1:1 complex, [Formula: see text] showed a reduced dimerization constant compared to the uncoordinated parent monomer Zn-1. At high quinuclidine concentration, the 1:1 complex, [Formula: see text], derived from the coordinated dimer dissociation was also detected. The 1H NMR spectra of the titrations displayed separate signals for some hydrogen atoms of the Zn-phthalocyanine in each one of the four species. Remarkably, the chemical exchange processes involving free and bound quinuclidine in the monomeric and dimeric complexes showed different kinetics on the NMR timescale.

Magnetic concentration and polymorphism in di-n-octyl-, di-n-decyl-, and di-n-dodecylphosphinates of copper(II)

1985 ◽  
Vol 63 (5) ◽  
pp. 1111-1117 ◽  
Author(s):  
John S. Haynes ◽  
Katherine W. Oliver ◽  
Robert C. Thompson
Keyword(s):  
Differential Scanning Calorimetry ◽  
Magnetic Susceptibility ◽  
Heisenberg Model ◽  
Variable Temperature ◽  
Electronic Spectroscopy ◽  
Chain Structure ◽  
Magnetic Data ◽  
Scanning Calorimetry ◽  
Extended Chain ◽  
Linear Chains

Phosphinates of copper(II) of the type Cu(R2PO2)2 where R is n-octyl, n-decyl, and n-dodecyl have been synthesized and characterized by differential scanning calorimetry, vibrational and electronic spectroscopy, and variable temperature (300 to 4.2 K) magnetic susceptibility studies. Each of these compounds was obtained in distinct α and β structural forms. All materials appear to have the double phosphinate bridged extended chain structure and the magnetic data have been successfully analyzed according to the isotropic Heisenberg model for linear chains. The α forms exhibit antiferromagnetic behaviour with J values of −25, −29, and −29 cm−1 for the octyl, decyl, and dodecyl derivatives respectively. The β forms are ferromagnetic and have corresponding J values of 1.8, 2.1, and 2.3 cm−1 respectively. Magneto-structural correlations in these extended chain coordination polymers are discussed.

scholarly journals Sonochemical-assisted magnesium borate synthesis from different boron sources

2017 ◽  
Vol 19 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Meral Yildirim ◽  
Azmi Seyhun Kipcak ◽  
Emek Moroydor Derun
Keyword(s):  
High Efficiency ◽  
Synthesis Method ◽  
Spectroscopic Studies ◽  
X Ray Diffraction ◽  
Magnesium Borate ◽  
Ir And Raman Spectroscopies ◽  
Ft Ir ◽  
Surface Morphologies ◽  
Ir And Raman ◽  
Good Agreement

Abstract In this study, sonochemical-assisted magnesium borate synthesis is studied from different boron sources. Various reaction parameters are successfully applied by a simple and green method. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and Raman spectroscopies are used to characterize the synthesized magnesium borates on the other hand surface morphologies are investigated by using scanning electron microscope (SEM). The XRD analyses showed that the products were admontite [MgO(B2O3)3 · 7(H2O)] with JCPDS (Joint Committee on Powder Diffraction Standards) no. of 01-076-0540 and mcallisterite [Mg2(B6O7(OH)6)2 · 9(H2O)] with JCPDS no. of 01-070-1902. The results that found in the spectroscopic studies were in a good agreement with characteristic magnesium borate bands in both regions of infra-red and visible. According to SEM results, obtained borates were in micro and sub-micro scales. By the use of ultrasonication, reaction yields were found between 84.2 and 97.9%. As a result, it is concluded that the sonochemical approach is a practicable synthesis method to get high efficiency and high crystallinity in the synthesis magnesium borate compounds.

scholarly journals P(VDF-TrFE) nanofibers: structure of the ferroelectric and paraelectric phases through IR and Raman spectroscopies

RSC Advances ◽  
2020 ◽  
Vol 10 (62) ◽  
pp. 37779-37796
Author(s):  
Alessia Arrigoni ◽  
Luigi Brambilla ◽  
Chiara Bertarelli ◽  
Gianluca Serra ◽  
Matteo Tommasini ◽  
...  
Keyword(s):  
Vinylidene Fluoride ◽  
Complex Morphology ◽  
Ir And Raman Spectroscopies ◽  
Poly Vinylidene Fluoride ◽  
Ir And Raman

This study elucidates the complex morphology and the related spectroscopic response of poly(vinylidene fluoride-co-trifluoroethylene) copolymer, with 80% molar VDF content, namely P(VDF-TrFE) (80/20).

Variable temperature Hirshfeld surface analysis of interdigitated calix[6]arene bearing O-alkyl C18 linear chains

CrystEngComm ◽  
2007 ◽  
Vol 9 (7) ◽  
pp. 566 ◽  
Author(s):  
Thomas E. Clark ◽  
Mohamed Makha ◽  
Joshua J. McKinnon ◽  
Alexandre N. Sobolev ◽  
Mark A. Spackman ◽  
...  
Keyword(s):  
Surface Analysis ◽  
Variable Temperature ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Linear Chains

scholarly journals Alp Inhibitors: Vanadyl(IV) Complexes Of Ferulic And Cinnamic Acid

2005 ◽  
Vol 60 (3) ◽  
pp. 305-311 ◽  
Author(s):  
Evelina G. Ferrer ◽  
María V. Salinas ◽  
María J. Correa ◽  
Fernanda Vrdoljak ◽  
Patricia A. M. Williams
Keyword(s):  
Alkaline Phosphatase ◽  
Cinnamic Acid ◽  
Alkaline Phosphatase Activity ◽  
Elemental Analysis ◽  
Diffuse Reflectance ◽  
Quinic Acid ◽  
Inhibitory Effect ◽  
Cinnamic Acids ◽  
Ir And Raman Spectroscopies ◽  
Ir And Raman

Two new vanadyl(IV) carboxylate complexes have been obtained: Na2[VO(Fer)2(CH3OH)2] and Na2[VO(Cin)2(CH3O)2] and characterized by elemental analysis and UV-vis, diffuse reflectance and IR and Raman spectroscopies (FerH2 = ferulic acid, CinH= cinnamic acid). The thermal behavior was also investigated. The inhibitory effect on alkaline phosphatase activity was tested for the compounds and ferulic and cinnamic acids as well as for the vanadyl(IV) complex of quinic acid for comparison. The ferulic complex together with the free ligands exhibited the lowest inhibitory effect, while the VO/quinic and VO/cinnamic complexes showed an intermediate inhibition potential

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