scholarly journals Water in the Alluaudite Type-Compounds: Synthesis, Crystal Structure and Magnetic Properties of Co3(AsO4)0.5+x(HAsO4)2−x(H2AsO4)0.5+x[(H,□)0.5(H2O,H3O)0.5]2x+

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1372
Author(s):  
Tamara Đorđević ◽  
Ljiljana Karanović ◽  
Marko Jagodič ◽  
Zvonko Jagličić
Keyword(s):  
Crystal Structure ◽  
Tetrahedral Site ◽  
Hydroxyl Group ◽  
Dimensional Structure ◽  
Site Symmetry ◽  
Hydroxyl Groups ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Hydrothermal Conditions ◽  
Cobalt Ions

In this study, a new cobalt arsenate belonging to the alluaudite supergroup compounds with the general formula of Co3(AsO4)0.5+x(HAsO4)2−x(H2AsO4)0.5+x[(H,□)0.5(H2O,H3O)0.5]2x+ (denoted as CoAsAllu) was synthesized under hydrothermal conditions. Its crystal structure was determined by a room-temperature single-crystal X-ray diffraction analysis: space group C2/c, a = 11.6978(8), b = 12.5713(7), c = 6.7705(5) Å, β = 113.255(5)°, V = 914.76(11) Å3, Z = 2 for As6H8Co6O25. It represents a new member of alluaudite-like protonated arsenates and the first alluaudite-like phase showing both protonation of the tetrahedral site and presence of the H2O molecules in the channels. In the asymmetric unit of CoAsAllu, one of the two Co, one of the two As and one of the seven O atoms lie at 4e special positions (site symmetry 2). The crystal structure consists of the infinite edge-shared CoO6 octahedra chains, running parallel to the [101¯] direction. The curved chains are interconnected by [(As1O4)0.5(H2As1O4)0.5]2− and [HAs2O4]2− tetrahedra forming a heteropolyhedral 3D open framework with two types of parallel channels. Both channels run along the c-axis and are located at the positions (1/2, 0, z) and (0, 0, z), respectively. The H2 and H4 hydrogen atoms of O2H2 and O4H4 hydroxyl groups are situated in channel 1, while the uncoordinated water molecule H2O7 at half-occupied 4e special positions and hydrogen atoms of O6H6 hydroxyl group were found in channel 2. The results of the magnetic investigations confirm the quasi one-dimensional structure of divalent cobalt ions. They are antiferromagnetically coupled with the intrachain interaction parameter of J ≈ −8 cm−1 and interchain parameter of J’ ≈ −2 cm−1 that become effective below the Néel temperature of 3.4 K.

scholarly journals An investigation of polyhedral deformation in two mixed-metal diarsenates: SrZnAs2O7and BaCuAs2O7

2015 ◽  
Vol 71 (4) ◽  
pp. 330-337 ◽  
Author(s):  
Sabina Kovač ◽  
Ljiljana Karanović ◽  
Tamara Đorđević
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
General Formula ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Open Framework ◽  
Geometrical Characteristics ◽  
Barium Copper

Two isostructural diarsenates, SrZnAs2O7(strontium zinc diarsenate), (I), and BaCuAs2O7[barium copper(II) diarsenate], (II), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. The three-dimensional open-framework crystal structure consists of corner-sharingM2O5(M2 = Zn or Cu) square pyramids and diarsenate (As2O7) groups. Each As2O7group shares its five corners with five differentM2O5square pyramids. The resulting framework delimits two types of tunnels aligned parallel to the [010] and [100] directions where the large divalent nine-coordinatedM1 (M1 = Sr or Ba) cations are located. The geometrical characteristics of theM1O9,M2O5and As2O7groups of known isostructural diarsenates, adopting the general formulaM1IIM2IIAs2O7(M1II= Sr, Ba, Pb;M2II= Mg, Co, Cu, Zn) and crystallizing in the space groupP21/n, are presented and discussed.

A 2-D Zn(II) coordination polymer based on 4,5-imidazoledicarboxylate and bis(benzimidazole) ligands: synthesis, crystal structure and fluorescence properties

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Xinzhao Xia ◽  
Lixian Xia ◽  
Geng Zhang ◽  
Yuxuan Jiang ◽  
Fugang Sun ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Coordination Polymer ◽  
Zigzag Chain ◽  
Supramolecular Framework ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
Hydrogen Bond Interaction ◽  
X Ray ◽  
New Type ◽  
Solid State Fluorescence

Abstract In this work, a new type of zinc(II) coordination polymer {[Zn(HIDC)(BBM)0.5]·H2O} n (Zn-CP) was synthesized using 4,5-imidazoledicarboxylic acid (H3IDC) and 2,2-(1,4-butanediyl)bis-1,3-benzimidazole (BBM) under hydrothermal conditions. Its structure has been characterized by infrared spectroscopy, elemental analysis and single crystal X-ray diffraction analysis. The Zn(II) ion is linked by the HIDC2− ligand to form a zigzag chain by chelating and bridging, and then linked by BBM to form a layered network structure. Adjacent layers are further connected by hydrogen bond interaction to form a 3-D supramolecular framework. The solid-state fluorescence performance of Zn-CP shows that compared with free H3IDC ligand, its fluorescence intensity is significantly enhanced.

The first proof of protonated anion tetrahedra in the tsumcorite-type compounds

2004 ◽  
Vol 68 (5) ◽  
pp. 757-767 ◽  
Author(s):  
T. Mihajlović ◽  
H. Effenberger
Keyword(s):  
Crystal Structure ◽  
Hydrothermal Synthesis ◽  
Single Crystal ◽  
Diffraction Data ◽  
Title Compound ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Synthetic Compounds ◽  
X Ray

AbstractHydrothermal synthesis produced the new compound SrCo2(AsO4)(AsO3OH)(OH)(H2O). The compound belongs to the tsumcorite group (natural and synthetic compounds with the general formula M(1)M(2)2(XO4)2(H2O,OH)2; M(1)1+,2+,3+ = Na, K, Rb, Ag, NH4, Ca, Pb, Bi, Tl; M(2)2+,3+ = Al, Mn3+, Fe3+, Co, Ni, Cu, Zn; and X5+,6+ = P, As, V, S, Se, Mo). It represents (1) the first Sr member, (2) the until now unknown [7]-coordination for the M(1) position, (3) the first proof of (partially) protonated arsenate groups in this group of compounds, and (4) a new structure variant.The crystal structure of the title compound was determined using single-crystal X-ray diffraction data. The compound is monoclinic, space group P21/a, with a = 9.139(2), b = 12.829(3), c = 7.522(2) Å, β = 114.33(3)°, V = 803.6(3) Å3, Z = 4 [wR2 = 0.065 for 3530 unique reflections]. The hydrogen atoms were located experimentally.

scholarly journals Synthesis and crystal structure of a new polymorph of potassium europium(III) bis(sulfate) monohydrate, KEu(SO4)2·H2O

2018 ◽  
Vol 74 (2) ◽  
pp. 242-245 ◽  
Author(s):  
Avijit Kumar Paul
Keyword(s):  
Crystal Structure ◽  
Topological Analysis ◽  
Structural Connectivity ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Monoclinic Space Group ◽  
Hydrothermal Conditions ◽  
Metal Sulfate ◽  
Synthesis And Crystal Structure ◽  
Trigonal Prismatic

The mixed-metal sulfate, KEu(SO4)2·H2O, has been obtained as a new polymorph using hydrothermal conditions. The crystal structure is isotypic with NaCe(SO4)2·H2O and shows a three-dimensional connectivity of the tetrahedral sulfate units with EuIII and KI ions. Tricapped trigonal–prismatic EuO9 units and square-antiprismatic KO8 units link the SO4 tetrahedra, building the three-dimensional structure. Topological analysis reveals the existence of two nodes with 6- and 10-connected nets. The compound was previously reported [Kazmierczak & Höppe (2010). J. Solid State Chem. 183, 2087–2094] in the monoclinic space group P21/c with a similar structural connectivity and coordination environments to the present compound.

scholarly journals Redetermination of the crystal structure of RhPb2 from single-crystal X-ray diffraction data, revealing a rhodium deficiency

2021 ◽  
Vol 77 (12) ◽  
Author(s):  
Takashi Mochiku ◽  
Yoshitaka Matsushita ◽  
Nikola Subotić ◽  
Takanari Kashiwagi ◽  
Kazuo Kadowaki
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Structure Type ◽  
Site Symmetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Anisotropic Displacement Parameters ◽  
Slight Deficiency

RhPb2 (rhodium dilead) is a superconductor crystallizing in the CuAl2 structure type (space group I4/mcm). The Rh and Pb atoms are located at the 4a (site symmetry 422) and 8h (m.2m) sites, respectively. The crystal structure is composed of [RhPb8] antiprisms, which share their square faces along the c axis and the edges in the direction perpendicular to the c axis. We have succeeded in growing single crystals of RhPb2 and have re-determined the crystal structure on basis of single-crystal X-ray diffraction data. In comparison with the previous structure studies using powder X-ray diffraction data [Wallbaum (1943). Z. Metallkd. 35, 218–221; Havinga et al. (1972). J. Less-Common Met. 27, 169–186], the current structure analysis of RhPb2 leads to more precise unit-cell parameters and fractional coordinates, together with anisotropic displacement parameters for the two atoms. In addition and likewise different from the previous studies, we have found a slight deficiency of Rh in RhPb2, leading to a refined formula of Rh0.950 (9)Pb2.

A first Mn member in the struvite morphotropic series, CsMn(H2O)6(PO4): hydrothermal synthesis, crystal structure and interconnections within the family of related phosphates

2018 ◽  
Vol 74 (8) ◽  
pp. 936-943
Author(s):  
Galina V. Kiriukhina ◽  
Olga V. Yakubovich ◽  
Ekaterina M. Kochetkova ◽  
Olga V. Dimitrova ◽  
Anatoliy S. Volkov
Keyword(s):  
Crystal Structure ◽  
Ionic Radius ◽  
The Novel ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Cell Parameters ◽  
Structural Relationships ◽  
The Family

Caesium manganese hexahydrate phosphate, CsMn(H2O)6(PO4), was synthesized under hydrothermal conditions. Its crystal structure was determined from single-crystal X-ray diffraction data. The novel phase crystallizes in the hexagonal space group P63 mc and represents the first manganese member in the struvite morphotropic series, AM(H2O)6(TO4). Its crystal structure is built from Mn(H2O)6 octahedra and PO4 tetrahedra linked into a framework via hydrogen bonding. The large Cs atoms are encapsulated in the framework cuboctahedral cavities. It is shown that the size of the A + ionic radius within the morphotropic series AM(H2O)6(XO4) results is certain types of crystal structures and affects the values of the unit-cell parameters. Structural relationships with Na(H2O)Mg(H2O)6(PO4) and the mineral hazenite, KNa(H2O)2Mg2(H2O)12(PO4)2, are discussed.

Crystal structure of atropine sulfate monohydrate, (C17H24NO3)2(SO4)·(H2O)

2019 ◽  
Vol 34 (4) ◽  
pp. 389-395 ◽  
Author(s):  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Water Molecule ◽  
Powder Diffraction ◽  
Density Functional ◽  
Atropine Sulfate ◽  
Strong Hydrogen Bond ◽  
Hydroxyl Groups ◽  
Hydrogen Atoms ◽  
Sulfate Anion

The crystal structure of atropine sulfate monohydrate has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Atropine sulfate monohydrate crystallizes in space group P21/n (#14) with a = 19.2948(5), b = 6.9749(2), c = 26.9036(5) Å, β = 94.215(2)°, V = 3610.86(9) Å3, and Z = 4. Each of the two independent protonated nitrogen atoms participates in a strong hydrogen bond to the sulfate anion. Each of the two independent hydroxyl groups acts as a donor in a hydrogen bond to the sulfate anion, but only one of the water molecule hydrogen atoms acts as a hydrogen bond donor to the sulfate anion. The hydrogen bonds are all discrete but link the cations, anion, and water molecule along [101]. Although atropine and hyoscyamine (atropine is racemic hyoscyamine) crystal structures share some features, such as hydrogen bonding and phenyl–phenyl packing, the powder patterns show that the structures are very different. The powder pattern for atropine sulfate monohydrate has been submitted to ICDD for inclusion in the Powder Diffraction File™.

scholarly journals Interactions of neosaxitoxin with the sodium channel of the frog skeletal muscle fiber.

1991 ◽  
Vol 97 (3) ◽  
pp. 561-578 ◽  
Author(s):  
S L Hu ◽  
C Y Kao
Keyword(s):  
Skeletal Muscle ◽  
Sodium Channel ◽  
Relative Abundance ◽  
Sodium Current ◽  
Ph Dependence ◽  
Hydroxyl Group ◽  
Dimensional Structure ◽  
Hydroxyl Groups ◽  
Frog Skeletal Muscle ◽  
Relative Potencies

Neosaxitoxin (neoSTX) differs structurally from saxitoxin (STX) in that the hydrogen on N-1 is replaced by a hydroxyl group. On single frog skeletal muscle fibers in the vaseline-gap voltage clamp, the concentrations for reducing the maximum sodium current by 50% (ED50) at pH's 6.50, 7.25, and 8.25 are, respectively, 4.9, 5.1, and 8.9 nM for STX and 1.6, 2.7, and 17.2 nM for neoSTX. The relative potencies of STX at the different pH's closely parallel the relative abundance of the protonated form of the 7,8,9 guanidinium function, but the relative potencies of neoSTX at the same pH's vary with the relative abundance of the deprotonated N-1 group. In constant-ratio mixtures of the two toxins, the observed ED50's are consistent with the notion that the two toxins compete for the same site. At pH's 6.50 and 7.25, the best agreement between observed and computed values is obtained when the efficacy term (epsilon) for either toxin is 1. At pH 8.25 the best agreement is obtained if the efficacy is 1 for STX but 0.75 for neo-STX. The marked pH dependence of the actions of neoSTX probably reflects the presence of a site in the receptor that interacts with the N-1 -OH, in addition to those interacting with the 7,8,9 guanidinium and the C-12 hydroxyl groups. Considering the three-dimensional structure of the STX and neoSTX molecules, the various site points are probably located in a fold or a crevice of the channel protein, where the extracellular orifice of the sodium channel is located.

A mononuclear cobalt(III) 3-(2-pyridyl)-5-phenyl-1,2,4-triazolato complex: hydrothermal synthesis, crystal structure, thermostability, and DFT calculations

2015 ◽  
Vol 70 (9) ◽  
pp. 631-636 ◽  
Author(s):  
Huaixian Liu ◽  
Lin Sun ◽  
Huiliang Zhou ◽  
Peipei Cen ◽  
Xiaoyong Jin ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Density Functional ◽  
Free Ligand ◽  
Supramolecular Network ◽  
Stacking Interactions ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
Functional Theory ◽  
X Ray ◽  
Mononuclear Cobalt

AbstractStarting with 1H-3-phenyl-5-(pyridin-2-yl)-1,2,4-triazole (1-Hppt), a Co(III) complex, [Co(ppt)3] (1), has been synthesized by reaction with CoF3 under hydrothermal conditions and characterized by its infrared spectrum and elemental analysis. The structure was determined by single-crystal and powder X-ray diffraction. Density functional theory (DFT) was employed to determine the optimized geometry and preferred conformation of the free ligand. A supramolecular network is formed via π–π stacking interactions. The conformation and geometry of the ligands correspond with the calculated results.

AN INVESTIGATION OF THE CHLORINATION OF SPRUCE WOOD AND OF THE RESULTING CHLOROLIGNIN

1937 ◽  
Vol 15b (7) ◽  
pp. 279-294 ◽  
Author(s):  
G. V. Jansen ◽  
J. W. Bain
Keyword(s):  
Methyl Alcohol ◽  
Ring Structure ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Hydrogen Atoms ◽  
Chlorine Atoms ◽  
Spruce Wood ◽  
Simple Substitution ◽  
Homogeneous Fraction ◽  
Acid Reduction

Spruce sawdust was chlorinated under various conditions in an attempt to procure a homogeneous lignin chloride. Success finally attended the use of methyl alcohol as a medium for chlorination. The lignin chloride, which was dissolved by the alcohol during the chlorination and subsequently precipitated by the addition of water, was cream white in color, and analysis showed it to be an alcohol lignin.A homogeneous fraction (No. 2) was obtained from the re-chlorinated product, and it proved to be a chlorinated analogue of Hibbert's monomethylated methyl alcohol lignin, the formulas of the two products being C42H22O6Cl13(OH)2(OCH3)7, and C42H32O6(OH)3(OCH3)7. The molecular weight and the presence of the two hydroxyl groups were confirmed by acetylation, when 2.0 acetyl groups entered the molecule. Eleven of the chlorine atoms in Fraction 2 have evidently replaced ten hydrogen atoms and one hydroxyl group by simple substitution in methyl alcohol lignin, leaving two chlorine atoms which have apparently entered to saturate a double bond. Seven of these chlorine atoms have been shown to be readily removable either by an alkali or by acid reduction. The other six, because of their stable union with the molecule, are surmised to be joined to an aromatic nucleus or at least to some type of ring structure. The product has been shown to react stoichiometrically within limits as narrow as could be expected for such a large molecule.

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