The crystal structure of a pyridine-vermiculite complex

Clay Minerals ◽  
1967 ◽  
Vol 7 (2) ◽  
pp. 145-153 ◽  
Author(s):  
K. Susa ◽  
H. Steinfink ◽  
W. F. Bradley
Keyword(s):  
Cation Exchange Capacity ◽  
Three Dimensional ◽  
Exchange Capacity ◽  
Water Molecules ◽  
Hydrogen Ions ◽  
X Ray Diffraction ◽  
Difference Electron Density ◽  
Cell Water ◽  
X Ray ◽  
Density Maps

AbstractA pyridine-vermiculite complex has been investigated by three dimensional X-ray diffraction techniques. The preparation of the complex was carried out at a pH ∼ 4 using a solution of pyridinium hydrochloride. Exsolved magnesium from the octahedral positions satisfied approximately one-half of the cation exchange capacity. The rest of the exchange capacity is satisfied by hydrogen ions and pyridinium ions which are statistically distributed over crystallographic sites so that less than three electrons per Å3 are present at any given point. Three dimensional difference electron density maps did not locate the carbon atoms except to indicate that the organic molecule occupies positions in the true and in the two pseudo mirror planes in the unit cell. Water molecules were present in the interlayer in octahedral arrangement around the cation as in the natural mineral.

scholarly journals The three-dimensional structure of a class-Pi glutathione S-transferase complexed with glutathione: the active-site hydration provides insights into the reaction mechanism

1998 ◽  
Vol 333 (3) ◽  
pp. 811-816 ◽  
Author(s):  
Antonio PÁRRAGA ◽  
Isabel GARCÍA-SÁEZ ◽  
Sinead B. WALSH ◽  
Timothy J. MANTLE ◽  
Miquel COLL
Keyword(s):  
Conformational Changes ◽  
Active Site ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Glutathione S Transferase ◽  
X Ray ◽  
The Right

The structure of mouse liver glutathione S-transferase P1-1 complexed with its substrate glutathione (GSH) has been determined by X-ray diffraction analysis. No conformational changes in the glutathione moiety or in the protein, other than small adjustments of some side chains, are observed when compared with glutathione adduct complexes. Our structure confirms that the role of Tyr-7 is to stabilize the thiolate by hydrogen bonding and to position it in the right orientation. A comparison of the enzyme–GSH structure reported here with previously described structures reveals rearrangements in a well-defined network of water molecules in the active site. One of these water molecules (W0), identified in the unliganded enzyme (carboxymethylated at Cys-47), is displaced by the binding of GSH, and a further water molecule (W4) is displaced following the binding of the electrophilic substrate and the formation of the glutathione conjugate. The possibility that one of these water molecules participates in the proton abstraction from the glutathione thiol is discussed.

scholarly journals Synthesis, Structures and Electrochemical Properties of Lithium 1,3,5-Benzenetricarboxylate Complexes

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 126 ◽  
Author(s):  
Pei-Chi Cheng ◽  
Bing-Han Li ◽  
Feng-Shuen Tseng ◽  
Po-Ching Liang ◽  
Chia-Her Lin ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Electrode Materials ◽  
Three Dimensional ◽  
Lithium Ion ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Crystal Transformation ◽  
Discharge Capacities

Four lithium coordination polymers, [Li3(BTC)(H2O)6] (1), [Li3(BTC)(H2O)5] (2), [Li3(BTC)(μ2-H2O)] (3), and [Li(H2BTC)(H2O)] (4) (H3BTC = 1,3,5-benzenetricarboxylatic acid), have been synthesized and characterized. All the structures have been determined using single crystal X-ray diffraction studies. Complexes 1 and 2 have two-dimensional (2-D) sheets, whereas complex 3 has three-dimensional (3-D) frameworks and complex 4 has one-dimensional (1-D) tubular chains. The crystal-to-crystal transformation was observed in 1–3 upon removal of water molecules, which accompanied the changes in structures and ligand bridging modes. Furthermore, the electrochemical properties of complexes 3 and 4 have been studied to evaluate these compounds as electrode materials in lithium ion batteries with the discharge capacities of 120 and 257 mAhg−1 in the first thirty cycles, respectively.

A lithium-bearing aluminian regular mixed layer montmorillonite-chlorite from Huy, Belgium

Clay Minerals ◽  
1974 ◽  
Vol 10 (3) ◽  
pp. 135-144 ◽  
Author(s):  
G. Brown ◽  
P. Bourguignon ◽  
J. Thorez
Keyword(s):  
Mixed Layer ◽  
Cation Exchange Capacity ◽  
Structural Formula ◽  
Exchange Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Saturated Clay ◽  
Bluish Green ◽  
Image Position ◽  
Green Clay

AbstractA bluish-green clay found in veins cutting across brecciated slates of the Llanvirnian stage at Huy, Belgium, is shown by X-ray diffraction and chemical analysis to be a lithium-bearing, aluminium-rich, regular mixed layer montmorillonite-chlorite with associated pyrophyllite, nacrite and quartz and smaller amounts of calcite and ankerite. The cation exchange capacity of the purified air-dry magnesium saturated clay is 49 mEq/100 g and its structural formula isThe problem of the nomenclature of regular mixed layer montmorillonite-chlorites is discussed.

A novel dinuclear bismuth(III) coordination compound: bis(μ-pyridine-2,6-dicarboxylato)-κ4O2,N,O6:O6′;κ4O2:O2′,N,O6-bis[(azido-κN)(1,10-phenanthroline-κ2N,N′)bismuth(III)] tetrahydrate

2014 ◽  
Vol 70 (6) ◽  
pp. 562-565 ◽  
Author(s):  
Wei Zhang ◽  
Yu-Quan Feng
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonds ◽  
Coordination Compound ◽  
Photoelectron Spectroscopy ◽  
Three Dimensional ◽  
Water Molecules ◽  
Stacking Interactions ◽  
Coordination Geometry ◽  
X Ray Diffraction ◽  
X Ray

A novel dinuclear bismuth(III) coordination compound, [Bi2(C7H3NO4)2(N3)2(C12H8N2)2]·4H2O, has been synthesized by an ionothermal method and characterized by elemental analysis, energy-dispersive X-ray spectroscopy, IR, X-ray photoelectron spectroscopy and single-crystal X-ray diffraction. The molecular structure consists of one centrosymmetric dinuclear neutral fragment and four water molecules. Within the dinuclear fragment, each BiIIIcentre is seven-coordinated by three O atoms and four N atoms. The coordination geometry of each BiIIIatom is distorted pentagonal–bipyramidal (BiO3N4), with one azide N atom and one bridging carboxylate O atom located in axial positions. The carboxylate O atoms and water molecules are assembledviaO—H...O hydrogen bonds, resulting in the formation of a three-dimensional supramolecular structure. Two types of π–π stacking interactions are found, with centroid-to-centroid distances of 3.461 (4) and 3.641 (4) Å.

A one-dimensional coordination polymer with a three-dimensional supramolecular framework:catena-poly[[[(3,4,7,8-tetramethyl-1,10-phenanthroline)cadmium(II)]-μ3-4,4′-sulfonyldibenzoato] trihydrate]

2013 ◽  
Vol 69 (3) ◽  
pp. 241-243 ◽  
Author(s):  
Jun Wang ◽  
Jian-Qing Tao ◽  
Xiao-Juan Xu ◽  
Chun-Yun Tan
Keyword(s):  
Three Dimensional ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Polymeric Compound ◽  
Chain Polymer ◽  
One Dimensional ◽  
X Ray ◽  
Carboxylate Groups ◽  
Metal Organic ◽  
Coordination Patterns

In the title mixed-ligand metal–organic polymeric compound, {[Cd(C14H8O6S)(C16H16N2)]·3H2O}n, the asymmetric unit contains a crystallographically unique CdIIatom, one doubly deprotonated 4,4′-sulfonyldibenzoic acid (H2SDBA) ligand, one 3,4,7,8-tetramethyl-1,10-phenanthroline (TMPHEN) molecule and three solvent water molecules. Each CdIIcentre is six-coordinated by two O atoms from a chelating carboxylate group of a SDBA2−ligand, two O atoms from monodentate carboxylate groups of two different SDBA2−ligands and two N atoms from a chelating TMPHEN ligand. There are two coordination patterns for the carboxylate groups of the SDBA2−ligand, with one in a μ1-η1:η1chelating mode and the other in a μ2-η1:η1bis-monodentate mode. Single-crystal X-ray diffraction analysis revealed that the title compound is a one-dimensional double-chain polymer containing 28-membered rings based on the [Cd2(CO2)2] rhomboid subunit. More interestingly, a chair-shaped water hexamer cluster is observed in the compound.

SEM, XRF, XRD, Nitrogen Adsorption, Fosters Swelling and Capacity Adsorption Characterization of Cloisite 30 B

2012 ◽  
Vol 727-728 ◽  
pp. 1591-1595 ◽  
Author(s):  
Aline Cadigena Lima Patrício ◽  
Marcílio Máximo da Silva ◽  
Anna Karoline Freires de Sousa ◽  
Mariaugusta Ferreira Mota ◽  
Meiry Glaúcia Freire Rodrigues
Keyword(s):  
Quaternary Ammonium ◽  
Cation Exchange Capacity ◽  
Nitrogen Adsorption ◽  
Exchange Capacity ◽  
X Ray Diffraction ◽  
Oil And Grease ◽  
X Ray ◽  
Quaternary Ammonium Cations ◽  
Cloisite 30B

Cationic surfactants, such as quaternary ammonium cations, have been used, in order to ameliorate the oil sorption capacity of inorganics materials, such as clays. Clays modified with quaternary ammonium cations (organoclays) have better performance in sorption, remove oil and grease from water at seven times the rate of activated carbon, as well as they can be used like perforation fluids of oil wells to the oil base, lubricants, among others industries. This work aims characterize the Cloisite 30B using various techniques: X-Ray Diffraction (XRD), Specific Surface Area (BET) and Cation Exchange Capacity. Different organic solvents, namely gasoline, diesel and kerosene were used in order to investigate the clays compatibility after orgophilization.

Physico-Mineralogical Characterization: Bentonitic Clays Recently Found in Olivedos, Paraíba, Brazil

2015 ◽  
Vol 820 ◽  
pp. 56-59
Author(s):  
F.K.A. Sousa ◽  
I.A. Silva ◽  
W.S. Cavalcanti ◽  
Gelmires Araújo Neves ◽  
Heber Carlos Ferreira
Keyword(s):  
Cation Exchange Capacity ◽  
Petroleum Industry ◽  
Specific Area ◽  
Exchange Capacity ◽  
X Ray Diffraction ◽  
Mineralogical Characterization ◽  
X Ray ◽  
Petroleum Wells ◽  
The Town

Used in various branches of the industry, bentonitic clays are considered a valuable mineral, used specially in the petroleum industry for manufacturing of fluids used the drilling of petroleum wells in long depth. Recently, a deposit of this valuable mineral was discovered in the town of Olivedos-PB. There are data that prove that this is a very poor and underdeveloped town. So, this work aims at the physico-mineralogical characterization of clays recently discovered and, this way, verify if they present similar characteristics which allow them to replace the clays from Boa Vista-PB, and if they can be used by the industry, thus bringing social development for that town. The characterization was made by means of the analysis of chemical composition by X-ray fluorescence (EDX), thermogravimetric and thermal differential analyses (TG and DTA), X-ray diffraction (XRD), cation-exchange capacity (CEC) and specific area (SA). The results show that the clays recently discovered in Olivedos-PB are polycationic clays, presenting MgO, CaO and K2O content, and that they are constituted by smectitic clay mineral, by quartz and kaolinite.

Alteration of smectites induced by hydrolytic exchange

Clay Minerals ◽  
2005 ◽  
Vol 40 (1) ◽  
pp. 15-24 ◽  
Author(s):  
S. Ramirez ◽  
D. Righi ◽  
S. Petit
Keyword(s):  
Infrared Spectroscopy ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Relative Increase ◽  
Exchange Capacity ◽  
Capacity Analysis ◽  
Soluble Salts ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mixed Layers

AbstractHydrolytic exchange was performed experimentally on four smectitic clays to evaluate the extent of clay alteration induced by this process and the associated ‘auto-transformation’ of H+ clays. Clay samples were Na-saturated and submitted to 10, 50 and 100 wetting-drying (WD) cycles and characterized after treatment using X-ray diffraction (XRD), infrared spectroscopy (FTIR) and cation exchange capacity analysis. Evidence for hydrolytic exchange was given by increasing amounts of exchangeable Mg2+ and precipitation of Na soluble salts for samples subjected to 100 WD cycles. Results indicated a decrease in the interlayer charge after 10 WD cycles but no further decrease was observed after 50 and 100 WD cycles. For one sample, XRD data indicated a decrease in the proportion of the smectite phase and a relative increase in the concentration of illite-smectite mixed layers also present in the sample. The results suggested that the reaction induces first a decrease in the layer charge and then a partial dissolution of some smectite layers.

scholarly journals Characterisation of Natural and HDTMA-Br Modified Dijah-Monkin Bentonite Clay: FTIR, XRF, XRD and SEM

2021 ◽  
Vol 7 (5) ◽  
pp. 2010-2018
Author(s):  
Olukayode Gideon Oloyede ◽  
◽  
Umar Omeiza Aroke ◽  
Saidat Olanipekun Giwa ◽  
Alexander Asanja Jock ◽  
...  
Keyword(s):  
Cation Exchange Capacity ◽  
Bentonite Clay ◽  
Exchange Capacity ◽  
Basal Spacing ◽  
Hexadecyltrimethylammonium Bromide ◽  
Acid Activation ◽  
X Ray Diffraction ◽  
X Ray ◽  
North East ◽  
Scanning Electron

In this study, Dijah-Monkin bentonite clay was modified with a cationic surfactant hexadecyltrimethylammonium bromide (HDTMA-Br) at the level of twice the cation exchange capacity (CEC). This process results in the development of hydrophobic organoclay with an improved adsorption capacity. The clay obtained from Zing LGA Taraba State, North-East Nigeria, was beneficiated and pulverised to a particle size of 125 µm. The modification was performed without acid activation to prevent damages to the clay’s crystal structure. The organoclay was characterised for chemical composition, functional groups, mineralogical and surface morphology using X-ray fluorescence (XRF), Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The XRD showed an increase in the basal spacing from 15.681Å to 17.758 Å, while the XRF revealed a 5.35% concentration of Br on the modified clay, indicating successful intercalation. The FTIR spectra also revealed the appearance of symmetric and asymmetric stretching bands at 2847.7cm-1 and 2914.8cm-1, respectively, as a consequence of the modification, resulting in more sites for adsorption.

scholarly journals Study On The Performance Of Carbonate-Mineralized Bacteria Combined With Eggshell For Immobilizing Pb and Cd in Water And Soil

2021 ◽  
Author(s):  
Ting Wei ◽  
Noman Yashir ◽  
Fengqiu An ◽  
Syed Asad Imtiaz ◽  
Xian Li ◽  
...  
Keyword(s):  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Contaminated Water ◽  
Carbonate Precipitation ◽  
Bacterial Isolates ◽  
X Ray Diffraction ◽  
X Ray ◽  
Soil Enzymatic Activity ◽  
Microbially Induced Carbonate Precipitation ◽  
Eggshell Waste

Abstract Microbially induced carbonate precipitation (MICP) is an advanced bioremediation approach to remediate heavy metals (HMs) contaminated water and soil. In this study, metal tolerant urease-producing bacterial isolates, namely UR1, UR16, UR20 and UR21, were selected based on their urease activity. The efficiency of these isolates in water for Pb and Cd immobilization was explored. Our results revealed that UR21 had the highest removal rates of Pb (81.9%) and Cd (65.0%) in solution within 72 h through MICP. The scanning electron microscopy-energy dispersive x-ray and x-ray diffraction analysis confirmed the structure and the existence of PbCO3 and CdCO3 crystals in the precipitates. In addition, the strain UR21, in combination with urea/eggshell waste (EGS) or both, was further employed to investigate the effect of MICP on soil enzymatic activity, chemical fractions and bioavailability of Pb and Cd. The outcomes indicated that the applied treatments reduced the proportion of soluble-exchangeable Pb and Cd, resulted an increment in carbonated bound Pb and Cd in the soil. The DTPA extractable Pb and Cd was reduced by 29.2% and 25.2% with the treatment of UR21 + urea + EGS as compared to the control. Besides, the application of UR21 and EGS significantly increased the soil pH, cation exchange capacity, and enzyme activities. Our findings may provide a novel perceptive for an eco-friendly and sustainable approach to remediate heavy metal contaminated environment through a combination of metal-resistant ureolytic bacterial strain and EGS.

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