scholarly journals Crystal structure of Zn2(HTeO3)(AsO4)

2021 ◽  
Vol 77 (5) ◽  
pp. 555-558
Author(s):  
Felix Eder ◽  
Matthias Weil
Keyword(s):  
Hydrothermal Reaction ◽  
Three Dimensional ◽  
Lone Pair ◽  
Site Symmetry ◽  
Hydroxide Group ◽  
Molar Ratios ◽  
Distorted Trigonal Bipyramid ◽  
Stereochemical Activity ◽  
By Products ◽  
Oxygen Atoms

Single crystals of Zn2(HTeO3)(AsO4), dizinc(II) hydroxidodioxidotellurate(IV) oxidoarsenate(V), were obtained as one of the by-products in a hydrothermal reaction between Zn(NO3)2·6H2O, TeO2, H3AsO4 and NH3 in molar ratios of 2:1:2:10 at 483 K for seven days. The asymmetric unit of Zn2(HTeO3)(AsO4) contains one Te (site symmetry m), one As (m), one Zn (1), five O (three m, two 1) and one H (m) site. The ZnII atom exhibits a coordination number of 5 and is coordinated by four oxygen atoms and a hydroxide group, forming a distorted trigonal bipyramid. The hydroxide ion is positioned at a significantly larger distance on one of the axial positions of the bipyramid. The [ZnO4OH] polyhedra are connected to each other by corner-sharing to form ∞ 2[ZnO3/2(OH)1/2O1/1] layers extending parallel to (001). The TeIV atom is coordinated by three oxygen atoms and a hydroxide group in a one-sided manner in the shape of a bisphenoid, revealing stereochemical activity of its 5s 2 electron lone pair. The AsV atom is coordinated by four oxygen atoms to form the tetrahedral oxidoarsenate(V) anion. By corner-sharing, [TeO3OH] and [AsO4] groups link adjacent ∞ 2[ZnO3/2(OH)1/2O1/1] layers along [001] into a three-dimensional framework structure.

scholarly journals The crystal structure of a new CdTe2O5 polymorph, isotypic with ∊-CaTe2O5

2020 ◽  
Vol 76 (6) ◽  
pp. 831-834
Author(s):  
Felix Eder ◽  
Matthias Weil
Keyword(s):  
Crystal Structure ◽  
Hydrothermal Reaction ◽  
Lone Pair ◽  
Quantitative Comparison ◽  
The Other ◽  
Asymmetric Unit ◽  
Molar Ratios ◽  
Wyckoff Position ◽  
By Products ◽  
Oxygen Atoms

Single crystals of cadmium pentaoxidoditellurate(IV), CdTe2O5, were obtained as by-products in a hydrothermal reaction of Cd(NO3)2·4H2O, TeO2, H6TeO6 and NH3 (molar ratios 2:1:1:6) at 483 K for seven days. The crystals represent a different polymorph (henceforth referred to as the β-form) than the α-CdTe2O5 crystals grown from the melt, and are isotypic with hydrothermally grown ∊-CaTe2O5. The asymmetric unit of β-CdTe2O5 comprises one Cd, two Te and five O sites, all of which are located in general positions (Wyckoff position 4 e). The cadmium(II) atom is coordinated by seven oxygen atoms, forming 2 ∞[CdO6/2O1/1] (100) layers. Both tellurium sites are surrounded by four oxygen atoms with one of them being at a significantly longer distance than the other three. The resulting bisphenoidal [TeO4] units also form layers propagating parallel to (100) by sharing edges with each other. The stereochemically active 5s 2 lone pair of the TeIV atoms leads to the formation of large channels extending along [011] and smaller ones along [010]. A quantitative comparison between the crystal structures of β-CdTe2O5 and ∊-CaTe2O5 is made.

scholarly journals Mixed-metal phosphates K1.64Na0.36TiFe(PO4)3 and K0.97Na1.03Ti1.26Fe0.74(PO4)3 with a langbeinite framework

2021 ◽  
Vol 77 (12) ◽  
Author(s):  
Igor V. Zatovsky ◽  
Nataliia Yu. Strutynska ◽  
Ivan V. Ogorodnyk ◽  
Vyacheslav N. Baumer ◽  
Nickolai S. Slobodyanik ◽  
...  
Keyword(s):  
High Temperature ◽  
Single Crystals ◽  
Three Dimensional ◽  
The Other ◽  
Site Symmetry ◽  
Mixed Metal ◽  
Metal Phosphates ◽  
Temperature Range ◽  
Molar Ratios ◽  
Sodium Cations

Single crystals of the langbeinite-type phosphates K1.65Na0.35TiFe(PO4)3 and K0.97Na1.03Ti1.26Fe0.74(PO4)3 were grown by crystallization from high-temperature self-fluxes in the system Na2O–K2O–P2O5–TiO2–Fe2O3 using fixed molar ratios of (Na+K):P = 1.0, Ti:P = 0.20 and Na:K = 1.0 or 2.0 over the temperature range 1273–953 K. The three-dimensional framework of the two isotypic phosphates are built up from [(Ti/Fe)2(PO4)3] structure units containing two mixed [(Ti/Fe)O6] octahedra (site symmetry 3) connected via three bridging PO4 tetrahedra. The potassium and sodium cations share two different sites in the structure that are located in the cavities of the framework. One of these sites has nine and the other twelve surrounding O atoms.

Oxotellurate(IV) der Lanthanide: II. Die isotype Reihe M2Te5O13 (M = Dy – Lu) / Oxotellurates(IV) of Lanthanides: II. The Isotypic Series M2Te5O13 (M = Dy – Lu)

2005 ◽  
Vol 60 (7) ◽  
pp. 720-726 ◽  
Author(s):  
Steffen F. Meier ◽  
Thomas Schleid
Keyword(s):  
Electron Pair ◽  
Three Dimensional ◽  
Lone Pair ◽  
Formula Unit ◽  
Partial Structure ◽  
Tellurium Oxide ◽  
Stereochemical Activity ◽  
Formula Type ◽  
Trigonal Prismatic ◽  
Bonding Electron

For the shortly discovered formula type M2Te5O13 (triclinic, P1̄), the establishment of an isostructural series in the last third of the lanthanide family (M = Dy - Lu) was possible. The excessive formula unit TeO2 additional to the well-known composition M2Te4O11 (monoclinic, C2/c) leads to the slicing of the [M2O10]14− layers which are typical for the tellurium-oxide poorer compounds. By coupling together the bicapped trigonal prismatic (M1, CN = 8) and the pentagonal bipyramidal (M2, CN = 7) lanthanide-oxygen polyhedra via edges, [M4O20]28− bands are formed stretching along the a axis and piling up to a primitive rod-packing. The linkage of these bands occurs parallel to the (010) plane via Te3 as well as via Te4 parallel to (100). Besides the usual 3+1 coordination, two of the five crystallographically independent tellurium sites are coordinated regularly fourfold (d(Te−O) ≈ 186−213 pm) and even 3+2-fold by oxygen atoms. The tellurium-oxygen polyhedra form corrugated layers running parallel to (101) which follow so close to each other that the tellurium-oxygen partial structure appears to be almost three-dimensional at a passing glance. As in M2Te4O11-type representatives, the non-bonding electron pair (lone pair) of each Te4+ cation shows stereochemical activity which always appears to flock together in large tellurium neighboured positions.

NdClSeO3 and ErClSeO3: First Chloride-Selenites of the Rare Earth Elements

2002 ◽  
Vol 57 (12) ◽  
pp. 1414-1418 ◽  
Author(s):  
Mathias S. Wickleder
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Single Crystals ◽  
Three Dimensional ◽  
Chloride Ions ◽  
Dimensional Structure ◽  
Electron Pairs ◽  
Dimensional Network ◽  
Stereochemical Activity ◽  
Oxygen Atoms

Violet single crystals of NdClSeO3 (Pnma, Z = 8, a = 1115.3(2), b = 535.19(6), c = 1356.8(1) pm, Rall = 0.0281) were obtained from the reaction of Nd2O3, NdCl3, and SeO2 in evacuated silica ampoules. The analogous procedure using Er2O3 and ErCl3 led to pink single crystals of ErClSeO3 (Pnma, Z = 4, a = 721.8(1), b = 692.2(1), c = 874.3(2) pm, Rall = 0.0305). The crystal structure of NdClSeO3 contains two crystallographically different neodymium ions. Nd(2)3+ is coordinated by four oxygen atoms and four chloride ions while eight oxygen atoms and one Cl− ion are connected to Nd(1)3+. The linkage of the polyhedra leads to a three-dimensional structure. In the structure of ErClSeO3 the Er3+ ion is coordinated by two Cl− ions, three O-monodentate SeO32− and one O,O-chelating SeO32− groups. The [ErO5Cl2] polyhedra can be seen as pentagonal bipyramids, which are connected in the [010] direction via opposite edges of oxygen atoms to infinite chains. These are further linked via chloride ions to give a three-dimensional network. In both crystal structures a prominent stereochemical activity of the lone electron pairs of the selenite ions can be observed.

Synthesis, spectroscopic and structural studies of O-methyl and O-isopropyl monothiocarbonate (monoxanthate) derivatives of dimethyl-and diphenyltellurium(IV). Crystal structures of Me2Te[SCO2(i-Pr)]2, Ph2Te[SCO2(i-Pr)]2, Me2TeCl[SCO2Me], and Me2TeBr[SCO2(i-Pr)]

1996 ◽  
Vol 74 (11) ◽  
pp. 1968-1982 ◽  
Author(s):  
John E. Drake ◽  
Robert J. Drake ◽  
Layla N. Khasrou ◽  
Anil G. Mislankar ◽  
Raju Ratnani ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Key Words ◽  
Lone Pair ◽  
Supramolecular Interactions ◽  
Equatorial Position ◽  
Structural Studies ◽  
Cell Parameters ◽  
Distorted Trigonal Bipyramid ◽  
Derivatives Of ◽  
Oxygen Atoms

Monothiocarbonate derivatives of diorganotellurium(IV), R2Te[SCO2R′]2, and R2TeX[SCO2R′], where R = Me, Ph; R′ = Me, i-Pr; X = Cl, Br, and I, have been prepared and characterized by vibrational and 1H, 13C, and 125Te NMR spectroscopy. Me2Te[SCO2(i-Pr)]2 (2): P21/n (No. 14) with cell parameters a = 6.942(6) Å, b = 25.599(3) Å, c = 9.404(6) Å, β = 94.48(6)°, V = 1666(1) Å3, Z = 4, R = 0.0648, Rw = 0.0624; Ph2Te[SCO2(i-Pr)]2 (4): P21/n (No. 14) with a = 12.360(4) Å, b = 12.277(3) Å, c = 15.066(3) Å, β = 102.82(2)°, V = 2229.1(9) Å3, Z = 4, R = 0.0368, Rw = 0.0312; Me2TeCl[SCO2Me] (5); P21/c (No. 14) with a = 5.193(2) Å, b = 18.118(4) Å, c = 9.613(5) Å, β = 91.31(6)°, V = 904.2(6) Å3, Z = 4, R = 0.0396, Rw = 0.0361; and Me2TeBr[SCO2(i-Pr)] (8): P21/n (No. 14) with a = 11.701(2) Å, b = 6.250(2) Å, c = 16.152(2) Å, β = 98.43(1)°, V = 1168.4(4) Å3, Z = 4, R = 0.0369, Rw = 0.0325. In all molecules, the immediate environment about tellurium is that of the saw-horse structure in which the lone pair is assumed to be stereochemically active and occupying an equatorial position in a distorted trigonal bipyramid. In 2 and 5, the terminal oxygen atoms are oriented toward tellurium, whereas in 4, one O(i-Pr) group is oriented toward tellurium, as it is in 8. In the latter cases, the terminal oxygen atoms act as weak bridges to form a pseudo dimeric species in 4 and a pseudo polymer in 8. Supramolecular interactions in 2 and 5 lead to a sulfur-bridged dimer in the former and a chlorine-bridged polymer in the latter. Key words: structure, tellurium, dimethyl, diphenyl, monothiocarbonates.

Monte Carlo Simulation of Precipitate Nucleation and Growth: Time Dependent Results

1988 ◽  
Vol 141 ◽  
Author(s):  
James P. Lavine ◽  
Gilbert A. Hawkins
Keyword(s):  
Monte Carlo ◽  
Crystalline Silicon ◽  
Three Dimensional ◽  
Nucleation Site ◽  
Nucleation And Growth ◽  
Lattice Points ◽  
Growth Time ◽  
Decay Kinetics ◽  
Time Step ◽  
Oxygen Atoms

AbstractA three-dimensional Monte Carlo computer program has been developed to study the heterogeneous nucleation and growth of oxide precipitates during the thermal treatment of crystalline silicon. In the simulations, oxygen atoms move on a lattice with randomly selected lattice points serving as nucleation sites. The change in free energy that the oxygen cluster would experience in gaining or losing one oxygen atom is used to govern growth or dissolution of the cluster. All the oxygen atoms undergo a jump or a growth decision during each time step of the anneal. The growth and decay kinetics of each nucleation site display interesting fluctuation phenomena. The time dependence of the cluster size generally differs from the expected 3/2 power law due to the fluctuations in oxygen arrival at and incorporation in a precipitate. Competition between growing sites and coarsening are observed.

scholarly journals Crystal structure of 2-methyl-1H-imidazol-3-ium aquatrichlorido(oxalato-κ2O,O′)stannate(IV)

2015 ◽  
Vol 71 (5) ◽  
pp. 520-522 ◽  
Author(s):  
Mouhamadou Birame Diop ◽  
Libasse Diop ◽  
Laurent Plasseraud ◽  
Thierry Maris
Keyword(s):  
Hydrogen Bonds ◽  
Water Molecule ◽  
Three Dimensional ◽  
Free Oxygen ◽  
Coordination Environment ◽  
Dimensional Network ◽  
Oxalate Ligand ◽  
Distorted Octahedral ◽  
Distorted Octahedral Coordination Environment ◽  
Oxygen Atoms

The tin(IV) atom in the complex anion of the title salt, (C4H7N2)[Sn(C2O4)Cl3(H2O)], is in a distorted octahedral coordination environment defined by three chlorido ligands, an oxygen atom from a water molecule and two oxygen atoms from a chelating oxalate anion. The organic cation is linked through a bifurcated N—H...O hydrogen bond to the free oxygen atoms of the oxalate ligand of the complex [Sn(H2O)Cl3(C2O4)]−anion. Neighbouring stannate(IV) anions are linked through O—H...O hydrogen bonds involving the water molecule and the two non-coordinating oxalate oxygen atoms. In combination with additional N—H...Cl hydrogen bonds between cations and anions, a three-dimensional network is spanned.

On the consequences of the stereochemical activity of the Bi(iii) 6s2 lone pair in cyclen-based complexes. The [Bi(DO3A)] case

2018 ◽  
Vol 47 (39) ◽  
pp. 13830-13842 ◽  
Author(s):  
Rosa Pujales-Paradela ◽  
Aurora Rodríguez-Rodríguez ◽  
Antonella Gayoso-Padula ◽  
Isabel Brandariz ◽  
Laura Valencia ◽  
...  
Keyword(s):  
Lone Pair ◽  
Spatial Arrangement ◽  
Stereochemical Activity

The spatial arrangement of donor atoms in Bi(iii) cyclen derivatives modulates the orientation and activity of the 6s2 lone pair.

A three-dimensional manganese(II) coordination polymer with two functional properties: magnetism and photochemical detection

2021 ◽  
Vol 77 (12) ◽  
Author(s):  
Dan Zhao ◽  
Yanyan An ◽  
Tingting Guo ◽  
Juanzhi Yan ◽  
Danmei Song
Keyword(s):  
Coordination Polymer ◽  
Hydrothermal Reaction ◽  
Three Dimensional ◽  
Building Blocks ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Detection Mechanism ◽  
Susceptibility Data ◽  
Dichromate Ions ◽  
Ditopic Ligand

Hydrothermal reaction of Mn2+ with the ditopic ligand 2,5-bis(1H-1,2,4-triazol-1-yl)benzoic acid (Hdtba) resulted in the complex poly[aqua[μ3-2,5-bis(1H-1,2,4-triazol-1-yl)benzoato-κ3 N 4:N 4′:O]chloridomanganese(II)] monohydrate], {[Mn(C11H7N6O2)Cl(H2O)]·H2O} n , (I). Coordination polymer I has been characterized by X-ray diffraction, IR spectroscopy, elemental analysis, thermogravimetry and susceptibility measurements. The topology of I corresponds to a three-dimensional (3,6)-conn net linked by {Mn2Cl2(COO)2} building blocks and dtba− anions. Significant antiferromagnetic exchange is observed within the dinuclear {Mn2Cl2(COO)2} subunits. A fit of the susceptibility data resulted in the magnetic parameters g = 1.93 and J = −1.52. Studies of the photoluminescence properties revealed that I represents a promising luminescence sensor for sensitively detecting dichromate ions in aqueous solution. The associated photochemical detection mechanism was studied in detail.

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