Structure and optical non-linearity of PbO.2B2O3

1996 ◽  
Vol 52 (2) ◽  
pp. 260-265 ◽  
Author(s):  
D. L. Corker ◽  
A. M. Glazer
Keyword(s):  
Room Temperature ◽  
Three Dimensional ◽  
Asymmetric Distribution ◽  
X Ray Diffraction ◽  
Acta Cryst ◽  
X Ray ◽  
Dimensional Network ◽  
Non Linear ◽  
Linear Optical ◽  
Atomic Coordinates

The crystal structure of lead tetraborate, PbO.2B2O3, has been refined using single-crystal X-ray diffraction data (Mo Kα radiation, λ = 0.71069 Å). Crystal data at room temperature: Mr = 362.43, orthorhombic, P21 nm (C 7 2v ), a = 4.251 (2), b = 4.463 (3), c = 10.860 (3) Å, V = 206.04 Å3 with Z = 2, μ = 402.6 cm−1, Dx = 5.88 Mg m−3, F(000) = 316, final R = 0.022, wR = 0.025 over 655 reflections with I > 2.5σ(I). Atomic coordinates are in general agreement with those previously reported for the isostructural compound, SrO.2B2O3, by Perloff & Block [Acta Cryst. (1966), 20, 274–279]. All the borons are tetrahedrally coordinated with a three-dimensional network formed from O atoms that are common to either two or three tetrahedra. The tetrahedra show deformation because the B—O bonds involving the two-coordinated O atoms are much shorter than those involved with three-coordinated O atoms. The Pb atoms are situated in empty tunnels running along [010] left by the network of tetrahedra. The Pb atoms display a highly asymmetric distribution of Pb—O bonding, with the five shortest bonds covering the range 2.483 (5)–2.664 (5) Å, being all situated to one side of the Pb atom. Preliminary investigations of the non-linear optical behaviour of lead tetraborate are also discussed. The results indicate that doping with barium should lead to a new non-linear optical material that is both phase-matchable and has a high optical non-linearity.

New Metal-Rich Compounds NblrSi, NblrGe, and TalrSi -Synthesis, Structure, and Magnetic Properties

2001 ◽  
Vol 56 (6) ◽  
pp. 463-468 ◽  
Author(s):  
Ratikanta Mishra ◽  
Rainer Pöttgen ◽  
Gunter Kotzyba
Keyword(s):  
Magnetic Properties ◽  
Silicon Germanium ◽  
High Frequency ◽  
Room Temperature ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Arc Melting ◽  
Dimensional Network ◽  
Pauli Paramagnetism

AbstractThe metal-rich intermetallic compounds NblrSi, NblrGe, and TalrSi were synthesized by arc-melting of the elements and subsequent annealing in glassy carbon crucibles in a high-frequency furnace. The three compounds were investigated by X-ray diffraction on powders and single crystals: TiNiSi type, Pnma, a = 641.27(3), b = 379.48(2), c = 727.70(3) pm, wR2 = 0.0773, 430 F2 values for NblrSi, a = 645.48(3), b = 389.21(2), c = 741.11(4) pm, wR2 = 0.0981, 297 F2 values for NblrGe, and a = 638.11(3), b = 378.69(2), c = 726.78(3) pm, wR2 = 0.0887, 290 F2 values for TalrSi with 20 variables for each refinement. The iridium and silicon (germanium) atoms form a three-dimensional network of puckered Ir3Si3 and Ir3Ge3 hexagons in which the niobium (tantalum) atoms fill larger cages. Magnetic susceptibility measurements on NblrSi and TalrSi indicate Pauli paramagnetism with room temperature susceptibilities of 0.30(5)·10-9 and 0.97(5)·10-9 m3/mol, respectively.

Syntheses, Structures and Photoluminescent Properties of the Two Novel Coordination Polymers [Cd(pydc)2(tu)]n and [Cd2(SO4)(nic)2(tu)1.5(H2O)2]n (pydc = Pyridine-2,3-dicarboxylate, nic = Nicotinate, tu = Thiourea)

2011 ◽  
Vol 66 (5) ◽  
pp. 459-464 ◽  
Author(s):  
Chao Xu ◽  
Sheng-Bo Liu ◽  
Taike Duan ◽  
Qun Chen ◽  
Qian-Feng Zhang
Keyword(s):  
Hydrogen Bonds ◽  
Coordination Polymers ◽  
Room Temperature ◽  
Three Dimensional ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
One Dimensional ◽  
X Ray ◽  
Dimensional Network

Two novel cadmium coordination polymers, [Cd(pydc)2(tu)]n (1) and [Cd2(SO4)(nic)2(tu)1.5 - (H2O)2]n (2) (pydc = pyridine-2,3-dicarboxylate, nic = nicotinate, tu = thiourea), have been synthesized under hydrothermal conditions and structurally characterized by X-ray diffraction analysis. 1 is a one-dimensional ladder coordination polymer in a two-dimensional network formed by hydrogen bonds. 2 consists of two kinds of Cd(II) centers in different coordination environments connected via nicotinate and sulfate to form a two-dimensional grid network integrated in a three-dimensional framework generated by hydrogen bonds. 2 shows intense fluorescent emission in the solid state at room temperature

The crystal structure of anthranilic acid

1968 ◽  
Vol 302 (1469) ◽  
pp. 185-199 ◽  
Keyword(s):  
Crystal Structure ◽  
Anthranilic Acid ◽  
Room Temperature ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bonding System ◽  
Hydrogen Bonding System ◽  
Acid Stable ◽  
Atomic Coordinates

The crystal structure of the form of anthranilic acid stable at room temperature has been determined from three-dimensional X -ray diffraction data. 1416 structure amplitudes were used in refining the positional and anisotropic thermal parameters, resulting in a discrepancy index R = 7.0% , and e. s. d. of 0.0045 Å in the atomic coordinates. There are two non-equivalent molecules per lattice point in the space group P 2 1 cn , and the analysis shows these two molecules to have considerably different bond lengths. This evidence, taken together with the hydrogen-bonding system, indicates that one molecule is neutral, while the other is a zwitterion.

Synthesis, Crystal Structure, Magnetic, Thermal and Fluorescent Properties of [Co(H2O)4(nia)2](suc)·(H2suc)

2010 ◽  
Vol 65 (6) ◽  
pp. 695-700 ◽  
Author(s):  
Selcuk Demir ◽  
Veysel T. Yilmaz ◽  
Jerzy Mroziński ◽  
Tadeusz Lis ◽  
Małgorzata Hołyńska
Keyword(s):  
Room Temperature ◽  
Complex Cation ◽  
Three Dimensional ◽  
Octahedral Geometry ◽  
Distorted Octahedral Geometry ◽  
X Ray Diffraction ◽  
Fluorescent Properties ◽  
X Ray ◽  
Dimensional Network ◽  
Distorted Octahedral

A new cobalt(II) complex, [Co(H2O)4(nia)2](suc)·(H2suc) [nicotinamide = nia, succinate = suc2−], has been synthesized and characterized by elemental analysis, IR, TG-DTA and single-crystal X-ray diffraction. It contains [Co(H2O)4(nia)2]2+ complex cations, uncoordinated suc2− anios and H2suc species. In the complex cation the cobalt(II) ion is coordinated by four aqua and two nia ligands in a distorted octahedral geometry. The suc2− dianion acts as a counter-ion, while H2suc is present as a molecule of solvation. A three-dimensional network is formed by O-H· · ·O and N-H· · ·O hydrogen bonds. The title complex exhibits luminescence in the solid state at room temperature. The magnetism of the complex was studied over the temperature range 1.8 - 300 K.

scholarly journals Crystal structure of K[Hg(SCN)3] – a redetermination

2014 ◽  
Vol 70 (9) ◽  
pp. i46-i46 ◽  
Author(s):  
Matthias Weil ◽  
Thomas Häusler
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
Three Dimensional ◽  
Lattice Parameters ◽  
Bond Lengths ◽  
Dimensional Network ◽  
Anisotropic Displacement Parameters ◽  
Precision And Accuracy ◽  
Standard Deviations ◽  
Atomic Coordinates

The crystal structure of the room-temperature modification of K[Hg(SCN)3], potassium trithiocyanatomercurate(II), was redetermined based on modern CCD data. In comparison with the previous report [Zhdanov & Sanadze (1952).Zh. Fiz. Khim.26, 469–478], reliability factors, standard deviations of lattice parameters and atomic coordinates, as well as anisotropic displacement parameters, were revealed for all atoms. The higher precision and accuracy of the model is, for example, reflected by the Hg—S bond lengths of 2.3954 (11), 2.4481 (8) and 2.7653 (6) Å in comparison with values of 2.24, 2.43 and 2.77 Å. All atoms in the crystal structure are located on mirror planes. The Hg2+cation is surrounded by four S atoms in a seesaw shape [S—Hg—S angles range from 94.65 (2) to 154.06 (3)°]. The HgS4polyhedra share a common S atom, building up chains extending parallel to [010]. All S atoms of the resulting1∞[HgS2/1S2/2] chains are also part of SCN−anions that link these chains with the K+cations into a three-dimensional network. The K—N bond lengths of the distorted KN7polyhedra lie between 2.926 (2) and 3.051 (3) Å.

Synthesis, structure and selective luminescence sensing for iron(III) ions of a three-dimensional zinc(II) (4,6)-connected coordination network

2019 ◽  
Vol 75 (2) ◽  
pp. 141-149 ◽  
Author(s):  
Feng Su ◽  
Cheng-Yong Zhou ◽  
Lin-Tao Wu ◽  
Xi Wu ◽  
Chun Han ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Electronic Configuration ◽  
Organic Ligands ◽  
Tetracarboxylic Acid ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carboxylate Groups ◽  
Dimensional Network ◽  
Solvent Stability ◽  
Solvothermal Conditions

Coordination polymers constructed from conjugated organic ligands and metal ions with a d 10 electronic configuration exhibit intriguing properties for chemical sensing and photochemistry. A ZnII-based coordination polymer, namely poly[aqua(μ6-biphenyl-3,3′,5,5′-tetracarboxylato)(μ2-4,4′-bipyridine)dizinc(II)], [Zn2(C16H6O8)(C10H8N2)(H2O)2] n or [Zn2(m,m-bpta)(4,4′-bipy)(H2O)2] n , was synthesized from a mixture of biphenyl-3,3′,5,5′-tetracarboxylic acid [H4(m,m-bpta)], 4,4′-bipyridine (4,4′-bipy) and Zn(NO3)2·6H2O under solvothermal conditions. The title complex has been structurally characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction and powder X-ray diffraction analysis, and features a μ6-coordination mode. The ZnII ions adopt square-pyramidal geometries and are bridged by two syn–syn carboxylate groups to form [Zn2(COO)2] secondary buildding units (SBUs). The SBUs are crosslinked by (m,m-bpta)4− ligands to produce a two-dimensional grid-like layer that exhibits a stair-like structure along the a axis. Adjacent layers are linked by 4,4′-bipy ligands to form a three-dimensional network with a {44.610.8}{44.62} topology. In the solid state, the complex displays a strong photoluminescence and an excellent solvent stability. In addition, the luminescence sensing results indicate a highly selective and sensitive sensing for Fe3+ ions.

Differences and similarities among hypoxanthinium nitrate hydrate structures

2019 ◽  
Vol 75 (8) ◽  
pp. 1036-1044 ◽  
Author(s):  
Małgorzata Katarzyna Cabaj ◽  
Roman Gajda ◽  
Anna Hoser ◽  
Anna Makal ◽  
Paulina Maria Dominiak
Keyword(s):  
Room Temperature ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
Acta Cryst ◽  
X Ray ◽  
Nitrate Hydrate ◽  
Different Temperatures ◽  
Lower Temperature ◽  
Low Temperature Phase ◽  
Nitrate Anions

Crystals of hypoxanthinium (6-oxo-1H,7H-purin-9-ium) nitrate hydrates were investigated by means of X-ray diffraction at different temperatures. The data for hypoxanthinium nitrate monohydrate (C5H5N4O+·NO3 −·H2O, Hx1) were collected at 20, 105 and 285 K. The room-temperature phase was reported previously [Schmalle et al. (1990). Acta Cryst. C46, 340–342] and the low-temperature phase has not been investigated yet. The structure underwent a phase transition, which resulted in a change of space group from Pmnb to P21/n at lower temperature and subsequently in nonmerohedral twinning. The structure of hypoxanthinium dinitrate trihydrate (H3O+·C5H5N4O+·2NO3 −·2H2O, Hx2) was determined at 20 and 100 K, and also has not been reported previously. The Hx2 structure consists of two types of layers: the `hypoxanthinium nitrate monohydrate' layers (HX) observed in Hx1 and layers of Zundel complex H3O+·H2O interacting with nitrate anions (OX). The crystal can be considered as a solid solution of two salts, i.e. hypoxanthinium nitrate monohydrate, C5H5N4O+·NO3 −·H2O, and oxonium nitrate monohydrate, H3O+(H2O)·NO3 −.

Centrosymmetric or Noncentrosymmetric? Case Study, Generalization and Structural Redetermination of Sr5Nb5O17

1998 ◽  
Vol 54 (4) ◽  
pp. 399-416 ◽  
Author(s):  
S. C. Abrahams ◽  
H. W. Schmalle ◽  
T. Williams ◽  
A. Reller ◽  
F. Lichtenberg ◽  
...  
Keyword(s):  
Niobium Oxide ◽  
The Novel ◽  
Physical Measurement ◽  
X Ray Diffraction ◽  
Acta Cryst ◽  
Data Set ◽  
Space Group ◽  
X Ray ◽  
Atomic Coordinates

The possibility that the structure of the novel semiconducting perovskite-related material strontium niobium oxide, Sr5Nb5O17, refined by Schmalle et al. [Acta Cryst. (1995), C51, 1243–1246] in space group Pnn2, might instead belong to space group Pnnm has been investigated following an analysis of the atomic coordinates that indicated the latter space group to be more likely. All I obs were carefully remeasured, first those within a hemisphere containing c *, then all that lay within the full sphere of reflection. Refinement was undertaken, with each of two different sets of weights, in each space group. Each data set was used under three limiting intensity conditions: I obs > 4σ(I obs), I obs > 2σ(I obs) and finally with all reflections, but setting magnitudes with I obs ≤ 0 equal to 0. Fourteen separate tests based only upon the X-ray diffraction data may be used to distinguish between Pnn2 and Pnnm. Nine tests favored the latter choice, four were indeterminate and one was not used. Seven further tests may be made on the basis of physical measurement; of these, three strongly indicated Pnnm, one was indeterminate and three could not be used. The evidence clearly suggests the space group is Pnnm. The use of all reflections, including those with negative magnitude set equal to zero, is essential to avoid ambiguity in the X-ray diffraction tests and achieve the highest reliability. Refinement with weights based on variances of Type A and Type B [Schwarzenbach et al. (1995). Acta Cryst. A51, 565–569] resulted in improved reliability compared with that obtained from a popular empirical weighting scheme. The revised structure differs in several respects from that published previously.

Crystal and Molecular Structure of 3-Iodo-2-propynyl-N-butylcarbamate

1997 ◽  
Vol 52 (2) ◽  
pp. 256-258 ◽  
Author(s):  
Evgeni V. Avtomonov ◽  
Rainer Grüning ◽  
Jörg Lorberth
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Title Compound ◽  
Crystal And Molecular Structure ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dimensional Network ◽  
Carbamate Group ◽  
Oxygen Atoms

Abstract The crystal structure of the title compound has been determined by X-ray diffraction methods. Due to the Lewis acidic character of the iodine substituent a “zig-zag” chain is formed via intermolecular interactions (2.933(4) A) between iodine and oxygen atoms of theocarbamate moiety. A three-dimensional network is formed through hydrogen-bridging (2.04 A) between NH-groups and the oxygen atoms of the neighbouring carbamate group of the next molecule.

A fourfold interpenetrating diamond-like three-dimensional zinc(II) coordination polymer: synthesis, crystal structure and physical properties

2019 ◽  
Vol 75 (5) ◽  
pp. 504-507 ◽  
Author(s):  
Hui-Ru Chen
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
Three Dimensional ◽  
Fluorescence Emission ◽  
Crystal Structure Analysis ◽  
The Novel ◽  
X Ray Diffraction ◽  
Metal Compounds ◽  
X Ray ◽  
Coordination Framework

Excellent fluorescence properties are exhibited by d 10 metal compounds. The novel three-dimensional ZnII coordination framework, poly[[{μ2-bis[4-(2-methyl-1H-imidazol-1-yl)phenyl] ether-κ2 N 3:N 3′}(μ2-furan-2,5-dicarboxylato-κ2 O 2:O 5)zinc(II)] 1.76-hydrate], {[Zn(C6H2O5)(C20H18N4O)]·1.76H2O} n , has been prepared and characterized using IR spectroscopy, elemental analysis and single-crystal X-ray diffraction. The crystal structure analysis revealed that the compound exhibits a novel fourfold interpenetrating diamond-like network. This polymer also displays a strong fluorescence emission in the solid state at room temperature.

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