New Coordination Compounds of Fe(III) with Organic Ligands

2009 ◽  
Vol 59 (12) ◽  
Author(s):  
Mihaela Flondor ◽  
Ioan Rosca ◽  
Doina Sibiescu ◽  
Mihaela-Aurelia Vizitiu ◽  
Daniel-Mircea Sutiman ◽  
...  

In this paper the synthesis and the study of some complex compounds of Fe(III) with ligands derived from: 2-(4-chloro-phenylsulfanyl)-1-(2-hydroxy-3,5-diiodo-phenyl)-ethanone (HL1), 1-(3,5-dibromo-2-hydroxy-phenyl)-2-phenylsulfanyl-ethanone(HL2), and 2-(4-chloro-phenylsulfanyl)-1-(3,5-dibromo-2-hydroxy-phenyl)-ethanone (HL3) is presented. The characterization of these complexes is based on method as: the elemental chemical analysis, IR and ESR spectroscopy, M�ssbauer, the thermogravimetric analysis and X-ray diffraction. Study of the IR and chemical analysis has evidenced that the precipitates form are a complexes and the combination ratio of M:L is 1:2. The central atoms of Fe(III) presented paramagnetic properties and a octaedric hybridization. Starting from this precipitation reactions, a method for the gravimetric determination of Fe(III) with this organic ligands has been possible. Based on the experimental data on literature indications, the structural formulae of the complex compounds are assigned.

Clay Minerals ◽  
2019 ◽  
Vol 54 (3) ◽  
pp. 283-291
Author(s):  
Victor Matheus Joaquim Salgado Campos ◽  
Luiz Carlos Bertolino ◽  
Luana Caroline Silveira Nascimento ◽  
José Yvan Pereira Leite ◽  
Vitor Schwenk Brandão ◽  
...  

AbstractThis research presents the mineralogical and chemical characterization and beneficiation study of two kaolin deposits from the Borborema Pegmatite Province, Brazil. Seven samples were collected and treated in two different beneficiation routes involving magnetic separation and chemical bleaching. The fractions obtained were studied by X-ray diffraction, X-ray fluorescence spectrometry, scanning electron microscopy, particle-size analyses, electron paramagnetic resonance and determination of optical properties. The samples are composed mainly of subhedral kaolinite in the form of booklets, as well as muscovite, quartz, microcline and illite impurities. The kaolinite structural formulae indicated significant replacement of Si4+ by Al3+ in tetrahedral sites and low replacement of Fe3+ by Al3+ in the octahedral sites. The first 30 min of chemical bleaching improved significantly the optical properties of kaolin, indicating that the process is more efficient than magnetic separation.


2014 ◽  
Vol 805 ◽  
pp. 486-491
Author(s):  
J.M.R. Figueirêdo ◽  
Juliana Melo Cartaxo ◽  
I.A. Silva ◽  
C.D. Silva ◽  
Gelmires Araújo Neves ◽  
...  

The State of Paraíba, Brazil, retains about 88.5% of all Brazilian bentonite, and much of this production comes from deposits in the District of Boa Vista, PB. Nevertheless, the deposits are almost depleted. Recently, new deposits were found, which will increases the reserves of the State, in the regions of Cubati and Pedra Lavrada, PB. The objective of this work is to characterize and develop purified clays, through sieving and hydrocycloning techniques, from those recently discovered bentonites for several applications. The characterization of the sample was done through granulometric analysis by laser diffraction, X-ray diffraction, chemical analysis by X-ray fluorescence, and thermogravimetric and differential thermal analysis. The results show that the samples are typical of bentonite clays, and that the purification solely by hydrocyclone presents the best results.


2016 ◽  
Vol 257 ◽  
pp. 147-151 ◽  
Author(s):  
Yi Wang ◽  
Svilen Bobev

Single-crystals of the new compound Ca14NbxIn1–xAs11 have been obtained from a solid-state reaction in a sealed Nb ampoule. The initial experiment had been set up with the aim to investigate the effect of electron doping (via In) on the crystal structure and physical properties of Ca14MnAs11. Subsequent single-crystal X-ray diffraction and elemental analysis work suggested that instead of Ca14MnxIn1–xAs11, the major product of the reaction is the phase Ca14NbxIn1–xAs11. This supposition was corroborated when the title compound was synthesized from a reaction of Ca, In and As in a sealed Nb ampoule, proving that, 1) Mn metal is not included in the structure, and 2) that the inadvertent side reaction of As with the walls of the Nb container is the source of the niobium. The overall structure is isotypic with the tetragonal Ca14AlSb11 structure type (space group I41/acd), although some marked differences between the two must be noted. Current ongoing work is focused on the synthesis of phase pure polycrystalline samples and determination of the physical properties of this unusual transition metal Zintl phase.


2016 ◽  
Vol 869 ◽  
pp. 159-163
Author(s):  
Danúbia Lisbôa da Costa ◽  
Ingrid Mayara Medeiros Fernandes ◽  
Aluska Nascimento Simões Braga ◽  
Rosiane Maria da Costa Farias ◽  
Romualdo Rodrigues Menezes ◽  
...  

Ornamental rocks are among the most promising business areas of the mineral sector, raising the necessity for, besides beauty, investments in quality, safety and characterization in the various application fields of these rocks. So, this work aims at the microstructural characterization of the class of these rocks: the Cariri Rocks, also known the limestone, which are calcareous rocks mainly formed by calcium and magnesium carbonate, possibly presenting variations due to their origins. For characterization, we studied four samples, being two from Chapada do Apodi and two from Chapada do Araripe, characterized physically and micro-structurally through chemical analysis, X-ray diffraction, optical micrography and porosimetry tests. The results prove that the limestones are calcitic and dolomitic, and present porosity varying from 5 to 15%, with pores concentration between 100nm and 10μm, besides the high microstructural heterogeneity.


2020 ◽  
Vol 8 (12) ◽  
pp. 1088-1095
Author(s):  
Abdoulkader Moussa Issaka ◽  
◽  
Bouba Hassane ◽  
Ibrahim Wagani ◽  
Amadou Abdourhamane Toure ◽  
...  

In order to characterizeclays of the Zinder region, 20 samples were taken from the quarries of Magaria, Mirriah, Guidimouni and Kolleram and four composite samples were made and representative of the quarries. These samples were subjected to chemical and mineralogical analyzes. Chemical analysis shows that the materials from these four quarries are aluminosilicates, but in varying proportions. The samplesfrom the Magaria and Kolleramquarries, contain proportions of carbonwhichinducethem a blackishcolor and alkaline and alkaline-earthelements (CaO, K2O, MgO. The samplesfromMirriah and Guidimouni,are veryrich in ironoxide (Fe2O3) whichinduces a reddishcolor. The main mineralogical phases detected by X-ray diffraction in the rawsamples and fine fractions from the four quarrieswere kaolinite, a mica structure close to illite and quartz.Thesequarriesthenconstitutekaolinicdeposits, primary and secondary. Those of Magaria and Kolleram are secondary and less favorable to formulations of ceramicproducts and those of Mirriah and Guidimouni are primary and very favorable to formulations of ceramicproductssuch as potteryfromMirriah.


2008 ◽  
Vol 591-593 ◽  
pp. 487-492 ◽  
Author(s):  
Monica Castoldi Borlini Gadioli ◽  
J.C.G. Correia ◽  
A. Caranassios

This work has for objective to characterize the clay from Vale do Mulembá-ES. The Vale do Mulembá is located in Joana D´Arc, Vitória in Espírito Santo State, Brazil. That clay is used in the production of the traditional clay pans of the State, what contributes to the economy of the area. The clay from Vale do Mulembá presents characteristics and behavior different from the other clays used for the production of clay pans. The characterization studies were carried out through chemical analysis, X-ray diffraction, particle size distribution, plasticity and thermal analyses (DTA, TGA). The results showed that the clay is typical kaolinitic, present relatively to the amount high of Al2O3 and high plasticity.


Clay Minerals ◽  
1990 ◽  
Vol 25 (3) ◽  
pp. 249-260 ◽  
Author(s):  
A. Plançon ◽  
C. Zacharie

AbstractUntil recently, the determination of the defect structures (previously referred to incorrectly as “crystallinity”) of kaolinites has been obtained in one of two ways: (1) measurement of the Hinckley index, or (2) by comparing calculated X-ray diffraction patterns based on a model of the defect structure (including types of defects and abundances) with experimental diffraction profiles. The Hinckley method is simple and easy to perform but contains no real information about the defect structure. Calculated XRD patterns are based on real defects but these calculations are time consuming and require some skill in application. Another approach is proposed: an expert system which will accurately describe the defect structure of kaolinites based on a few measurements taken from a normal powder diffraction profile. This system has been verified for nine kaolinite samples for which the defect structure was previously determined by comparison of calculated and observed diffraction profiles. The expert system reproduced the correct defect structure for each of the samples.


1991 ◽  
Vol 35 (A) ◽  
pp. 151-157
Author(s):  
G. Will ◽  
T. C. Huang ◽  
F. Sequeda

The structural characterization of thin films is important for research development and manufacturing of electronic, magnetic, optical, and other high-tech materials. The grazing incidence X-ray diffraction technique has bean used successfully for the determination of crystalline phases, structural-depth profiles, crystallite size, and strain, etc. of thin films with thickness's down to a few tens of Å, If the crystal structure, e.g. the distribution of atoms in the unit cell, or the crystallinity and texture (or preferred orientation) of a film is of interest, the conventional Bragg-Brentano diffractometer technique with the θ-2θ scanning geometry has been found to be appropriate.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Saleh S. Hayek

This study focuses on the synthesis and characterization of a magnetic nanomaterial used in magnetic hyperthermia. Cerium gadolinium zinc-iron (CeGdZnFe) magnetic nanoparticles were synthesized by a coprecipitation method for application as magnetic hyperthermia agents. Determination of phase purity and their identification was achieved by X-ray diffraction studies using a Phillips powder diffractometer with Cu Kα radiation. Typical TEM micrographs of the dispersion of CeGdZn-ferrite nanoparticles and CeGdZn-ferrite PEG-encapsulated nanoparticles in ethanol deposited over a Cu grid were taken as part of the characterization techniques to be used for newly developed materials. It was then fitted by a Gaussian distribution with mean diameter dm ±1.0 nm. The investigation of magnetic properties showed that adjusting, Gd and Zn contributes to the nanoparticles added to the adjustment of all magnetic properties of CeGdZnFe.


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