The Structural and Magnetic Properties of FeII and CoII Complexes with 2-(furan-2-yl)-5-pyridin-2-yl-1,3,4-oxadiazole

Two novel coordination compounds containing heterocyclic bidentate N,N-donor ligand 2-(furan-2-yl)-5-(pyridin-2-yl)-1,3,4-oxadiazole (fpo) were synthesized. A general formula for compounds originating from perchlorates of iron, cobalt, and fpo can be written as: [M(fpo)2(H2O)2](ClO4)2 (M = Fe(II) for (1) Co(II) for (2)). The characterization of compounds was performed by general physico-chemical methods—elemental analysis (EA), Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) in case of organics, and single crystal X-ray diffraction (sXRD). Moreover, magneto-chemical properties were studied employing measurements in static field (DC) for 1 and X-band EPR (Electron paramagnetic resonance), direct current (DC), and alternating current (AC) magnetic measurements in case of 2. The analysis of DC magnetic properties revealed a high spin arrangement in 1, significant rhombicity for both complexes, and large magnetic anisotropy in 2 (D = −21.2 cm−1). Moreover, 2 showed field-induced slow relaxation of the magnetization (Ueff = 65.3 K). EPR spectroscopy and ab initio calculations (CASSCF/NEVPT2) confirmed the presence of easy axis anisotropy and the importance of the second coordination sphere.

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The guanidinium t-diaqua-bis(oxalato)chromate(III) dihydrate complex: synthesis, crystal structure, EPR spectroscopy and magnetic properties

Zeitschrift für Naturforschung B ◽

10.1515/znb-2021-0006 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Idelle Nono Kamga ◽

Augustin Nkwento Nana ◽

Bridget Ndoye Ndosiri ◽

Frédéric Capet ◽

Michel Foulon ◽

...

Keyword(s):

Crystal Structure ◽

Magnetic Properties ◽

Three Dimensional ◽

X Ray Diffraction ◽

Paramagnetic Resonance ◽

Dimensional Network ◽

Ft Ir ◽

Water Ligands ◽

Electron Paramagnetic ◽

Oxygen Atoms

Abstract A new salt (CH6N3)[t-Cr(C2O4)2(H2O)2]·2H2O (1) (CH6N3 + = guanidinium cation) has been synthesized and characterized by single-crystal X-ray diffraction, FT-IR and UV–Vis spectroscopies, elemental and thermogravimetric analyses. In the crystal structure of 1, the chromate(III) ion lies on an inversion center in the form of an elongated octahedron. The coordination sphere consists of four oxygen atoms of two chelating oxalato ligands in the equatorial plane and two axial oxygen atoms of water ligands. The structural feature of focal interest in the structure of 1 is the formation of pillars of [Cr(C2O4)2(H2O)2]− complex anions and CH6N3 + guanidinium cations, with the next-neighbor cations rotated by an angle of 60° relative to each other. O–H···O and N–H···O hydrogen bonds play an important role in the construction of the three-dimensional network. The electron paramagnetic resonance (EPR) and magnetic properties of 1 have also been investigated.

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Production of Micro Crystalline Cellulose from Tapioca Solid Waste: Effect of Acid Concentration on its Physico-chemical Properties

Jurnal Kimia Sains dan Aplikasi ◽

10.14710/jksa.23.5.147-151 ◽

2020 ◽

Vol 23 (5) ◽

pp. 147-151

Author(s):

Ansharullah Ansharullah ◽

Nur Muhammad Abdillah Saenuddin ◽

RH Fitri Faradilla ◽

Asranuddin Asranudin ◽

Asniar Asniar ◽

...

Keyword(s):

Solid Waste ◽

Water Solubility ◽

Chemical Properties ◽

Xrd Analysis ◽

Sem Analysis ◽

Crystalline Cellulose ◽

Cellulose Content ◽

X Ray Diffraction ◽

Physico Chemical ◽

Ft Ir

This study was aimed to examine the production of microcrystalline cellulose (MCC) from tapioca solid waste (TSW), using HCl hydrolysis with various concentrations, i.e., 2 N, 2.5 N, 3 N, and 3.5 N. MCC was produced by delignifying the TSW with NaOH 20%, and bleaching with NaOCl 3.5% to produce α-cellulose, and subsequently hydrolyzing α-cellulose with three different HCl concentrations to produce MCC. The physicochemical properties of MCC were then analyzed, including Scanning Electron Micrograph (SEM), X-ray diffraction (XRD), and FTIR spectra. The results showed that hydrolysis with 2.0 N HCl resulted in a higher yield of 61.28%, α-cellulose content of 56.33%, moisture 6.25%, pH of 6.54; ash 0.23%, and water solubility 0.34%. SEM analysis showed the morphology and size of the MCC produced were like those of a commercial MCC (Avicel PH101), while the XRD analysis showed the higher concentration of HCl gave rise to an increased crystalline index. FT-IR spectrum analysis indicated that TSW, MCC produced, and commercial MCC had similar functional groups.

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Consequences of Fluoride Incorporation on Properties of Apatites

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.309-311.697 ◽

2006 ◽

Vol 309-311 ◽

pp. 697-700 ◽

Cited By ~ 4

Author(s):

Racquel Z. LeGeros ◽

Dindo Q. Mijares ◽

Fang Yao ◽

John P. LeGeros ◽

T. Bromage ◽

...

Keyword(s):

Crystal Size ◽

Chemical Properties ◽

Calcium Deficiency ◽

X Ray Diffraction ◽

X Ray ◽

Physico Chemical ◽

Lower Solubility ◽

Ft Ir ◽

Hydrolysis Of ◽

Ft Ir Spectroscopy

Fluoride, when incorporated in the apatite, stabilizes the structure. The purpose of this study was to determine the consequences of fluoride (F) substitution on the physico-chemical properties of apatites. F-containing apatites were prepared by precipitation or by hydrolysis of CaHPO4 in solutions containing different F concentrations and characterized using x-ray diffraction, FT-IR spectroscopy, scanning electron microscopy, thermogravimetry and chemical analyses. Results showed that F incorporation have the following effects: (a) decrease in a-axis dimension, (b) increase in crystal size and thickness, (c) decrease in calcium deficiency, and (d) lower solubility.

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Experimental and Physico-Chemical Comparison of ZnO Nanoparticles’ Activity for Photocatalytic Applications in Wastewater Treatment

Catalysts ◽

10.3390/catal11060678 ◽

2021 ◽

Vol 11 (6) ◽

pp. 678

Author(s):

Stefano Alberti ◽

Irene Basciu ◽

Marco Vocciante ◽

Maurizio Ferretti

Keyword(s):

Wastewater Treatment ◽

Zno Nanoparticles ◽

Energy Dispersive Spectrometer ◽

Chemical Properties ◽

X Ray Diffraction ◽

Commercial Sample ◽

Synthetic Process ◽

Physico Chemical ◽

Photocatalytic Applications ◽

Reflectance Measurements

In this contribution, the photoactivity upon activation by simulated sunlight of zinc oxide (ZnO) obtained from two different synthetic pathways (Acetate and Nitrate) is investigated for water purification. Different reagents and processes were exploited to obtain ZnO nanoparticles. Products have been characterized by means of X-Ray Diffraction, Scanning Electron Microscopy along with Energy Dispersive Spectrometer, Dynamic Light Scattering, and Diffuse Reflectance Measurements, to highlight the different outcomes ascribable to each synthesis. A comparison of characteristics and performances was also carried out with respect to commercial ZnO. Nanoparticles of this semiconductor can be obtained as aggregates with different degrees of purity, porosity, and shape, and their physical-chemical properties have been addressed to the specific use in wastewater treatment, testing their effectiveness on the photocatalytic degradation of methylene blue (MB) as a model pollutant. Excluding the commercial sample, experimental results evidenced a better photocatalytic behavior for the ZnO Nitrate sample annealed at 500 °C, which was found to be pure and stable in water, suggesting that ZnO could be effectively exploited as a heterogeneous photocatalyst for the degradation of emerging pollutants in water, provided that thermal treatment is included in the synthetic process.

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Electrospun Nanosystems Based on PHBV and ZnO for Ecological Food Packaging

Polymers ◽

10.3390/polym13132123 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2123

Author(s):

Maria Râpă ◽

Maria Stefan ◽

Paula Popa ◽

Dana Toloman ◽

Cristian Leostean ◽

...

Keyword(s):

Food Packaging ◽

Spin Trapping ◽

X Ray Diffraction ◽

Paramagnetic Resonance ◽

Hno3 Solution ◽

X Ray ◽

Trapping Method ◽

Ft Ir ◽

Doped Zno ◽

Electron Paramagnetic

The electrospun nanosystems containing poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and 1 wt% Fe doped ZnO nanoparticles (NPs) (with the content of dopant in the range of 0–1 wt% Fe) deposited onto polylactic acid (PLA) film were prepared for food packaging application. They were investigated by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), antimicrobial analysis, and X-ray photoelectron spectrometry (XPS) techniques. Migration studies conducted in acetic acid 3% (wt/wt) and ethanol 10% (v/v) food simulants as well as by the use of treated ashes with 3% HNO3 solution reveal that the migration of Zn and Fe falls into the specific limits imposed by the legislation in force. Results indicated that the PLA/PHBV/ZnO:Fex electrospun nanosystems exhibit excellent antibacterial activity against the Pseudomonas aeruginosa (ATCC-27853) due to the generation of a larger amount of perhydroxyl (˙OOH) radicals as assessed using electron paramagnetic resonance (EPR) spectroscopy coupled with a spin trapping method.

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Physico-Chemical and Morphological Changes of Sayong Kaolinite Clay Treated with Sulphuric Acid for Enzyme Immobilization

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.832.589 ◽

2013 ◽

Vol 832 ◽

pp. 589-595 ◽

Cited By ~ 1

Author(s):

N.A. Edama ◽

A. Sulaiman ◽

K.H. Ku Hamid ◽

M.N. Muhd Rodhi ◽

Mohibah Musa ◽

...

Keyword(s):

Surface Area ◽

Sulphuric Acid ◽

Enzyme Immobilization ◽

Morphological Changes ◽

Chemical Properties ◽

X Ray Diffraction ◽

Kaolinite Clay ◽

X Ray ◽

Mineral Oxides ◽

Physico Chemical

This study analyzed the effects of sulphuric acid (H2SO4) treatment on pysico-chemical properties and morphological changes of clay obtained from Sg. Sayong, Perak. The clay was ground and sieved to <150μm and treated with different concentrations of H2SO4. The treatment was completed by refluxing the clay with different concentration of H2SO4 (1M, 5M and 10M ) at 100 °C for 4 hours and followed by calcination at 500 °C for 1 hour. The physic-chemical properties and morphological changes of the untreated and treated clay were compared using Surface Area Analyser, X-Ray Diffraction (XRD), Field Emission Scanning Electron Micrograph (FESEM), X-Ray Diffraction (XRD) and Fourier Transformed Infrared Spectroscopy (FTIR). The results showed that acid treatment of 5M increased the surface area from 25 m2/g to 75 m2/g and the pore volume increased from 0.1518 cc/g to 0.3546 cc/g. The nanopore size of the clay decreased from 24.8 nm to 19.4 nm after treated with acid. This can be explained due to the elimination of the exchangeable cations and generation of microporosity. The results of XRF showed SiO2 increased from 58.34% to 74.52% and Al2O3 reduced from 34.6% to 18.31%. The mineral oxides such as Fe2O3, MgO, CaO, K2O and TiO2 also reduced. This concluded that H2SO4 treatment has led to significant removal of octahedral Al3+, Fe3+ cations and other impurities. In conclusion, this study showed the physico-chemical properties and morphology of Sayong clay were improved once treated with H2SO4 and therefore suggests better supporting material for enzyme immobilization.

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Albumen-mediated Green Synthesis of ZnFe2O4 Nanoparticles and Their Physico-Chemical Properties

Jordan Journal of Physics ◽

10.47011/14.5.6 ◽

2021 ◽

Vol 14 (5) ◽

pp. 445-449

Keyword(s):

Zinc Ferrite ◽

Single Phase ◽

Chemical Properties ◽

Synthesis Process ◽

X Ray Diffraction ◽

Scanning Microscope ◽

Physico Chemical ◽

Znfe2o4 Nanoparticles ◽

Photoluminescence Studies ◽

Combustion Technique

Abstract: Spinel ferrites with general formula AB2O4 possess charming magnetic and electrical properties owing to their thermal and chemical steadfastness. Spinel zinc ferrite (ZnFe2O4) nanoparticles have attracted massive attention due to their unusual amalgamation of properties, especially magnetic properties, where these properties are equipped as suitable candidates in the field of electronics. Here, a simple self-combustion technique is made with the assistance of albumen to synthesize nanocrystalline zinc ferrite (ZnFe2O4) particles. The egg white (albumen) that is used in the synthesis process plays the fuel role in the process of combustion. The results of the powder X-ray diffraction (PXRD) and Fourier Transform Infrared Spectroscopy (FTIR) suggested that the synthesized nanoparticles are of single phase and show spinel structure. The photoluminescence studies reported a doublet peak at around 360-380 nm. The functional groups present in the synthesized nanoparticles were revealed from FTIR data. EDX findings give an account of the percentage composition of the elements Fe, Zn and O present in the synthesized sample. High-resolution Scanning Microscope (HRSEM) reveals the agglomerated coalescence nature of ferrite nanoparticles. Keywords: Ferrite, PXRD, FTIR, HRSEM, EDX Albumen.

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Nitroxide radicals appended to phthalonitriles: synthesis, structural characterization and photophysical properties

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229621001832 ◽

2021 ◽

Vol 77 (3) ◽

pp. 137-143

Author(s):

Ismail Fidan ◽

Emel Onal ◽

Catherine Hirel

Keyword(s):

Magnetic Measurements ◽

Photophysical Properties ◽

Nucleophilic Aromatic Substitution ◽

Structural Studies ◽

Aromatic Substitution ◽

Nitronyl Nitroxide ◽

X Ray Diffraction ◽

X Ray ◽

Microwave Assisted ◽

Ft Ir

The syntheses of 4-[4-(4,4,5,5-tetramethyl-2-imidazoline-3-oxide-1-oxyl-2-yl)phenoxy]phthalonitrile (3, C21H19N4O3) and 4-[4-(4,4,5,5-tetramethyl-2-imidazoline-1-oxyl-2-yl)phenoxy]phthalonitrile (4) were carried out by microwave-assisted nucleophilic aromatic substitution of 4-nitrophthalonitrile (2) by the pre-formed 2-(4-hydroxyphenyl)-4,4,5,5-tetramethyl-2-imidazoline-3-oxide-1-oxyl (1). Compounds 3 and 4 were characterized unambiguously by a rich array of analyses, such as melting point, FT–IR, MALDI–TOF MS, elemental analysis, UV–Vis, CV, EPR, magnetic measurements and single-crystal X-ray diffraction. Structural studies demonstrate that the C—H...X and C—X...π (X = O and N) interactions in the radical nitronyl nitroxide groups play an important role in the assembly of the crystal structures. Moreover, cyclic voltammetry analyses show that the phthalonitrile substituent retains the redox properties of the Ullman radicals.

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Influence of Alloying Additions on Enhancement of Soft Magnetic Properties Effect and Crystallization in FeXSiB (X=Cu, V, Co, Zr, Nb) Amorphous Alloys

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.130.171 ◽

2007 ◽

Vol 130 ◽

pp. 171-174 ◽

Cited By ~ 3

Author(s):

Z. Stokłosa ◽

G. Badura ◽

P. Kwapuliński ◽

Józef Rasek ◽

G. Haneczok ◽

...

Keyword(s):

Magnetic Properties ◽

Amorphous Alloys ◽

Crystallization Process ◽

Annealing Temperature ◽

Magnetic Measurements ◽

X Ray Diffraction ◽

Soft Magnetic ◽

X Ray ◽

Second Stage ◽

Transmission Electron

The crystallization and optimization of magnetic properties effects in FeXSiB (X=Cu, V, Co, Zr, Nb) amorphous alloys were studied by applying X-ray diffraction methods, high resolution transmission electron microscopy (HRTEM), resistometric and magnetic measurements. The temperatures of the first and the second stage of crystallization, the 1h optimization annealing temperature and the Curie temperature were determined for different amorphous alloys. Activation energies of crystallization process were obtained by applying the Kissinger method. The influence of alloy additions on optimization effect and crystallization processes was carefully examined.

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Tuning Properties of Partially Reduced Graphene Oxide Fibers upon Calcium Doping

Nanomaterials ◽

10.3390/nano10050957 ◽

2020 ◽

Vol 10 (5) ◽

pp. 957 ◽

Cited By ~ 1

Author(s):

Krzysztof Tadyszak ◽

Jacek K. Wychowaniec ◽

Karol Załęski ◽

Emerson Coy ◽

Łukasz Majchrzycki ◽

...

Keyword(s):

Graphene Oxide ◽

Chemical Properties ◽

Fiber Axis ◽

Paramagnetic Resonance ◽

Physico Chemical ◽

Reduced Graphene ◽

Calcium Doping ◽

Bulk Structures ◽

Pulsed Electron Paramagnetic Resonance ◽

Electron Paramagnetic

The arrangement of two-dimensional graphene oxide sheets has been shown to influence physico-chemical properties of the final bulk structures. In particular, various graphene oxide microfibers remain of high interest in electronic applications due to their wire-like thin shapes and the ease of hydrothermal fabrication. In this research, we induced the internal ordering of graphene oxide flakes during typical hydrothermal fabrication via doping with Calcium ions (~6 wt.%) from the capillaries. The Ca2+ ions allowed for better graphene oxide flake connections formation during the hydrogelation and further modified the magnetic and electric properties of structures compared to previously studied aerogels. Moreover, we observed the unique pseudo-porous fiber structure and flakes connections perpendicular to the long fiber axis. Pulsed electron paramagnetic resonance (EPR) and conductivity measurements confirmed the denser flake ordering compared to previously studied aerogels. These studies ultimately suggest that doping graphene oxide with Ca2+ (or other) ions during hydrothermal methods could be used to better control the internal architecture and thus tune the properties of the formed structures.

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