scholarly journals Synthesis and Crystal Structure of the Short LnSb2O4Br Series (Ln = Eu–Tb) and Luminescence Properties of Eu3+-Doped Samples

Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1089
Author(s):  
Felix C. Goerigk ◽  
Veronica Paterlini ◽  
Katharina V. Dorn ◽  
Anja-Verena Mudring ◽  
Thomas Schleid
Keyword(s):  
Red Light ◽  
High Energy ◽  
Solid State Reactions ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
Light Emitting ◽  
Vertex Sharing ◽  
Photoluminescence Studies ◽  
Oxygen Atoms

Pale yellow crystals of LnSb2O4Br (Ln = Eu–Tb) were synthesized via high temperature solid-state reactions from antimony sesquioxide, the respective lanthanoid sesquioxides and tribromides. Single-crystal X-ray diffraction studies revealed a layered structure in the monoclinic space group P21/c. In contrast to hitherto reported quaternary lanthanoid(III) halide oxoantimonates(III), in LnSb2O4Br the lanthanoid(III) cations are exclusively coordinated by oxygen atoms in the form of square hemiprisms. These [LnO8]13− polyhedra form layers parallel to (100) by sharing common edges. All antimony(III) cations are coordinated by three oxygen atoms forming ψ1-tetrahedral [SbO3]3− units, which have oxygen atoms in common building up meandering strands along [001] according to {[SbO2/2vO1/1t]–}∞1 (v = vertex-sharing, t = terminal). The bromide anions are located between two layers of these parallel running oxoantimonate(III) strands and have no bonding contacts with the Ln3+ cations. Since Sb3+ is known to be an efficient sensitizer for Ln3+ emission, photoluminescence studies were carried out to characterize the optical properties and assess their suitability as light phosphors. Indeed, for both, GdSb2O4Br and TbSb2O4Br doped with about 1.0–1.5 at-% Eu3+ efficient sensitization of the Eu3+ emission could be detected. For TbSb2O4Br, in addition, a remarkably high energy transfer from Tb3+ to Eu3+ could be detected that leads to a substantially increased Eu3+ emission intensity, rendering it an efficient red light emitting material.

Synthesis and Crystal Structure of a Caesium Hydrogen Benzoylcyanoximate Complex with 18-Crown-6: Cs(18-Crown-6){H(L)2}

1997 ◽  
Vol 52 (8) ◽  
pp. 901-905 ◽  
Author(s):  
Vera V Ponomareva ◽  
Victor V Skopenko ◽  
Konstantin V Domasevitch ◽  
Joachim Sieler ◽  
Thomas Gelbrich
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Crown Ether ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
The Mean ◽  
Cyano Groups ◽  
Oxygen Atoms

Abstract The caesium hydrogen benzoylcyanoximate (L-) complex with 18-crown-6 of composition Cs(18-crown-6){H(L)2} has been prepared and studied by means of X-ray diffraction [monoclinic, space group P21/n, with a = 9.906(1), b = 18.387(3), c = 18.855(3)Å, β = 90.13(1)°, V = 3434.3(9) Å, Z = 4; final R1 = 0.043 for the 6431 independent reflections used. The lattice consists of Cs(18-crown-6)+ cations and complex hydrogen oximate anions {H(L)2}-, formed via strong hydrogen bonding between the oxygen atoms of nitroso-groups [O - - - O ca. 2.456(5)Å]. The caesium atom deviates by 1.492(3) Å from the mean plane of the oxygen atoms of the macrocyclic ether (dominant orientation of disordered ligand, 60%) and adopts a typical “sunrise coordination” [Cs-O (ether) 3.040(9)-3.312(7) Å]. The hydrogen oximate groups are bonded to the metal center only on one side of the crown ether plane via the oxygen atoms of nitroso-groups and the nitrogen atoms of cyano groups (Cs-O ca. 3.040(9), 3.312(7) Å; Cs-N ca. 3.469(5), 3.679(6) Å). The coordination polyhedron of Cs+ can be described as a distorted bicapped tetragonal prism.

scholarly journals SOLVENT-FREE SYNTHESIS AND CRYSTAL STRUCTURE OF rac-2-THIOHYDANTOIN-VALINE

2019 ◽  
Vol 16 (31) ◽  
pp. 347-352
Author(s):  
G. E. DELGADO ◽  
Asiloé J. MORA ◽  
T. GONZÁLEZ ◽  
I. SANTOS ◽  
P. RIVAS ◽  
...  
Keyword(s):  
Heterocyclic Ring ◽  
Solvent Free ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
One Dimensional ◽  
X Ray ◽  
Dimensional Network ◽  
Nmr Techniques ◽  
Solvent Free Synthesis

Thiohydantoins have been used in the manufacture of medicines and in industrial processes. Depending on the nature and type of substitution on the heterocyclic ring, these compounds may display pharmaceutical and biological activity with a variety of applications as antiepileptic, antitumoral, antiinflammatory, and principally for the treatment of prostate cancer. In this study, a new thiohydantoin was synthetized from the valine amino acid and structurally characterized. The title compound, C6H10N2O2S, with systematic name rac-5-isopropyl-2-tioxoimidazolidin-4-one, has been synthetized by a solvent-free synthesis. The heterocyclic compound was characterized by spectroscopic infrared (FTIR) and nuclear magnetic resonance (NMR) techniques, powder and single-crystal X-ray diffraction analysis (XRD). This material crystallizes in the monoclinic space group P21/c. In the supramolecular structure, the molecules are joined by N- --H···O and N---H···S hydrogen bonds, forming centrosymmetric R2 2(8) dimers and C2 2(9) chains that run along the [001] direction in an infinite one-dimensional network.

Photoluminescence studies on LiNa5(PO4)2:Dy3+, Sm3+ phosphor

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Miyapuram Ravi ◽  
Ghanta Pushpa Chakrapani ◽  
Mandava Balachandrika ◽  
Pavuluri Vasudevarao ◽  
Chendela Nageswararao ◽  
...  
Keyword(s):  
White Light ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
New Class ◽  
Light Region ◽  
Crystalline Nature ◽  
Photoluminescence Studies ◽  
White Light Emitting Diodes ◽  
Good Agreement ◽  
Pure White

Abstract This paper describes the preparation, structure and photoluminescence properties of a new class LiNa5(PO4)2:Dy3+, Sm3+-phosphor. Crystalline nature confirmed by X-ray diffraction. The phases obtained are in good agreement with the standard phase. Excitation dependence and concentration effect on luminescence features are investigated. Color purity and optical bandgap are also estimated for the LiNa5(PO4)2:Dy3+, Sm3+ phosphors. The result shows LiNa5(PO4)2:Dy3+, Sm3+-phosphor excited by 374 nm nUV light produces pure white light than others. Admixing of 4f configurations and energy transfer between dopants are identified while varying the concentration of Sm3+. The CIE coordinates for LiNa5(PO4)2:0.05Dy3+, 0.05Sm3+ (x = 0.309, y = 0.332) are positioned well in white light region and very close to pure white light. The present study on LiNa5(PO4)2:Dy3+, Sm3+-phosphor suggests that it is useful for the fabrication of white light emitting diodes.

Polysulfonylamine, LXIII [1] / Polysulfonylamines, LXIII [1]

1995 ◽  
Vol 50 (1) ◽  
pp. 128-138 ◽  
Author(s):  
Dagmar Henschel ◽  
Armand Blaschette ◽  
Peter G. Jones
Keyword(s):  
Hydrogen Bond ◽  
Phenyl Group ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
Space Group ◽  
Amine Molecule ◽  
Chain Sequence ◽  
O 193 ◽  
Oxygen Atoms

Complexes of Uncharged Molecules, Crystal StructureThe thermally labile ternary complexes 18C6 · 2MeOH · 2 HN(SO2Ph)2 (2a), 18C6 · 2MeOH · 2HN(SO2–C6H4-4-Cl)2 (2b) and 18C6 · 3 MeOH · HN(SO2Me)(SO2Ph) (3) were obtained by co-crystallization of 18-crown-6 (18C6) and the appropriate di(organosulfonyl)amine from methanolic solutions and characterized by low-temperature X-ray diffraction. The crystal structures of 2a (monoclinic, space group P21/n) and 2b (triclinic, space group P1̄) consist of monomeric, centrosymmetric formula units. Each di(arenesulfonyl)-amine molecule is connected to a methanol molecule by an N-Η ··· O hydrogen bond (H ··· O 203 pm in 2a, 190 pm in 2b). The methanol molecules are linked to three alternate crown oxygen atoms via one O-Η ··· O(crown) hydrogen-bond and two weaker C-Η ··· O(crown) interactions (OH ··· O 201 pm in 2a, 186 pm in 2b; CH ··· O 236 and 247 pm in 2a, 240 and 254 pm in 2b); two symmetry-related oxygen atoms of the crown are involved in O-Η ··· O and the other four in C-Η ··· O interactions. The structure of complex 3 (monoclinic, space group P21) is built of infinite chains parallel to [101]. The methyl group of the di(organosulfonyl)amine is bonded by C-Η ··· O(crown) interactions to a set of three alternate oxygen atoms of the cyclic polyether (H ··· O 228, 245 and 247 pm). Starting from the acidic NH function, a sequence of three methanol molecules catenated by hydrogen bonds curves around the bulky phenyl group and links with its terminal MeOH through one O-H ··· O(crown) and two C-Η ··· O(crown) bonds to the second set of alternate oxygen atoms in the adjacent symmetry-equivalent crown (OH ··· O 193 pm, CH ··· O 248 and 250 pm). Within the chain sequence N-H ··· O′(Me)H′ ··· O″(Me)H″ ··· O‴(Me)H, the H ··· O distances are H ··· O′ 184, H′ ··· O″ 189 and H″··· O‴ 183 pm. In the structures of 2a, 2b and 3, the crown rings adopt the frequently observed D3d pseudosymmetry.

Carbacylamidophosphates: Synthethis and Structure of N,N'-Tetramethyl-NM-benzoylphosphoryltriamide and Dimorpholido-N-benzoylphosphorylamide

2000 ◽  
Vol 55 (6) ◽  
pp. 495-498 ◽  
Author(s):  
Katerina E. Gubina ◽  
Vladimir A. Ovchynnikov ◽  
Vladimir M. Amirkhanov ◽  
Viktor V. Skopenkoa ◽  
Oleg V. Shishkinb
Keyword(s):  
Nmr Spectroscopy ◽  
Hydrogen Bonds ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Sodium Salts ◽  
Space Group ◽  
X Ray ◽  
Centrosymmetric Dimers ◽  
Oxygen Atoms

N,N′-Tetramethyl-N"-benzoylphosphoryltriamide (I) and dimorpholido-N-benzoylphosphorylamide (II), and their sodium salts Nal, Nall were synthesized and characterized by means of IR and 1H, 31P NMR spectroscopy. The structures of I, II were determined by X-ray diffraction: I monoclinic, space group P2i/c with a = 10.162(3), b= 11.469(4), c = 12.286(4) Å , β = 94.04°, V = 1428.4(8) A 3, Z = 4, p(calcd) = 1.187 g/cm3; II monoclinic, space group C2/c with a = 15.503(4), b = 10.991(3), c = 22.000(6) Å, β = 106.39°, V = 3596.3(17) Å3, Z = 8, p(calcd.) = 1.253 g/cm3. The refinement of the structures converged at R = 0.0425 for I, and R = 0.068 for II. In both structures the molecules are connected into centrosymmetric dimers via hydrogen bonds formed by the phosphorylic oxygen atoms and hydrogen atoms of amide groups.

Synthesis and luminescence properties of the red phosphor CaZrO3:Eu3+ for white light-emitting diode application

Open Physics ◽  
2011 ◽  
Vol 9 (4) ◽  
Author(s):  
Junli Huang ◽  
Liya Zhou ◽  
Yuwei Lan ◽  
Fuzhong Gong ◽  
Qunliang Li ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diode ◽  
Red Light ◽  
Average Diameter ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
Light Emitting ◽  
Near Ultraviolet ◽  
Light Region

AbstractEu3+-doped CaZrO3 phosphor with perovskite-type structure was synthesized by the high temperature solid-state method. The samples were characterized by X-ray diffraction, scanning electron microscopy, fluorescence spectrophotometer and UV-vis spectrophotometer, respectively. XRD analysis showed that the formation of CaZrO3 was at the calcinations temperature of 1400°C. The average diameter of CaZrO3 with 4 mol% doped-Eu3+ was 2µm. The PL spectra demonstrated that CaZrO3:Eu3+ phosphor could be excited effectively in the near ultraviolet light region (397 nm) and emitted strong red-emission lines at 616 nm corresponding to the forced electric dipole 5 D 0 → 7 F 2 transitions of Eu3+. Meanwhile, the light-emitting diode was fabricated with the Ca0.96ZrO3:Eu0.043+ phosphor, which can efficiently absorb ∼ 400 nm irradiation and emit red light. Therefore Ca0.96ZrO3:Eu0.043+ may have applications for a near ultraviolet InGaN chip-based white light-emitting diode.

Synthesis and Crystal Structure Determination of Cyclosporin H

2000 ◽  
Vol 65 (8) ◽  
pp. 1317-1328 ◽  
Author(s):  
Alexandr Jegorov ◽  
Ladislav Cvak ◽  
Aleš Husek ◽  
Petr Šimek ◽  
Anna Heydová ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Amino Acids ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Acid Catalyzed ◽  
Products Of Reaction ◽  
Cyclosporin H

Acid-catalyzed degradation of cyclosporin A was studied in various solvents and products of reaction were monitored by HPLC. Identification of amino acids and their chirality were determined after hydrolysis and derivatization by GC-MS. Cyclosporin H was isolated as the principal product and its structure was determined by X-ray diffraction: Cyclosporin H- diethyl ether-water (1 : 0.5 : 1) crystallizes in the monoclinic space group I2 with a = 12.338(2) Å, b = 18.963(2) Å, c = 34.074(3) Å, β = 96.47(2)°, Z = 4, and V = 7 921.4(17) Å3.

Synthesis and Crystal Structure of a Fe(II,III) Complex with 2-(4΄-Chlorine-benzoyl)-benzoic acid and 3-(2-Pyridyl)pyrazole

2013 ◽  
Vol 634-638 ◽  
pp. 2592-2595
Author(s):  
Qing Wei Wang ◽  
Ting Feng Lu ◽  
Jia Guo ◽  
Xiu Mei Li
Keyword(s):  
Crystal Structure ◽  
Benzoic Acid ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Organic Complex ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Elemental Analyses ◽  
Metal Organic Complex ◽  
Metal Organic

A new metal-organic complex FeII2FeIII2(cbba)4(L)6 (Hcbba = 2-(4΄-chlorine-benzoyl) benzoic acid, L = 3-(2-pyridyl)pyrazole) 1 has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analyses, TG and IR spectroscopy. The compound crystallizes in monoclinic, space group Cc with a = 17.729(5), b = 15.919(5), c = 33.650(5) Å, β = 92.058(5)°, V = 9491(4) Å3, C104H68Cl4Fe4N18O12, Mr = 2126.96, Dc = 1.489 g/cm3, μ(MoKα) = 0.786 mm1, F(000) = 4344, Z = 4, the final R = 0.0559 and wR = 0.1122 for 12093 observed reflections (I > 2(I)).

scholarly journals Synthesis and Crystal Structure of the New Telluric Acid Adduct (RbCl)3·Te(OH)6

2012 ◽  
Vol 67 (1) ◽  
pp. 1-4
Author(s):  
Dirk Mahlmeister ◽  
Elisabeth Irran
Keyword(s):  
Crystal Structure ◽  
Three Dimensional ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Tellurium Atom ◽  
Synthesis And Crystal Structure ◽  
Dimensional Network ◽  
Tricapped Trigonal Prism ◽  
Acid Adduct ◽  
Oxygen Atoms

The new telluric acid adduct (RbCl)3 ・ Te(OH)6 was prepared by dissolving RbCl and Te(OH)6 in the molar ratio of 3 : 1 in deionized water at r. t. and slow evaporation of the solvent in air. The crystal structure of the colorless crystals was determined with single-crystal X-ray diffraction (trigonal space group: R3̄c (no. 167), a = 14.4392(8), c = 10.4301(16) Å , Z = 6). In (RbCl)3 ・ Te(OH)6, the rubidium atom is surrounded by five chlorine and four oxygen atoms in form of an irregular tricapped trigonal prism. Each tellurium atom is octahedrally surrounded by six oxygen atoms. The Te(OH)6 octahedra and the RbCl5O4 polyhedra are linked to a dense three-dimensional network which is additionally strengthened by hydrogen bonds.

scholarly journals Synthesis and Photoluminescence Properties of Eu3+-Doped Na2YMg2V3O12: A Novel Red-Emitting Phosphor for White-Light-Emitting Diodes

2021 ◽  
Author(s):  
Weiyi Zhang ◽  
Yanqiu Shao ◽  
Ying Zhu ◽  
Yingying Shao ◽  
Zhaohui Huang ◽  
...  
Keyword(s):  
Solid State ◽  
White Light ◽  
Emission Band ◽  
Red Light ◽  
Solid State Reactions ◽  
Broad Emission Band ◽  
Light Emitting ◽  
Near Ultraviolet ◽  
Broad Emission ◽  
Red Emitting Phosphor

Abstract The fabrication and luminescent properties of novel Na2YMg2V3O12:Eu3+ phosphors produced by conventional solid-state reactions were investigated. Self-activated emission of the Na2YMg2V3O12 host produces a broad emission band ranging from 400 to 700 nm with a maximum peak at 530 nm, ascribed to the charge transfer in the (VO4)3− groups. Excitation with near-UV (365 nm) light causes the Na2YMg2V3O12:Eu3+ phosphors to emit bright red light, including both the broad emission band of the (VO4)3− groups and the sharp emission peaks of Eu3+ ions. At a quenching concentration of 0.03 mol, the Eu3+ ion emission peaks were located at 597, 613, 654 and 710 nm. As-prepared Na2YMg2V3O12:Eu3+ phosphors also exhibited stable emission at high temperatures. Furthermore, a designed and packaged white-light-emitting diode (WLED) lamp, including the obtained phosphors, commercial (Ba,Sr)2SiO4:Eu2+ green phosphors, BaMgAl10O17:Eu2+ blue phosphors and a near-ultraviolet (n-UV) chip, emitted bright white light with a good chromaticity coordinate of (0.3068, 0.3491), a satisfactory colour rendering index of 88.20 and a properly correlated colour temperature of 4460.52 K. These results indicate the potential of this Na2YMg2V3O12:Eu3+ phosphor as a red-emitting phosphor for solid-state illumination.

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