scholarly journals The Optical Properties of Crystalline Zn3Nb2O8Nanomaterials Obtained by Hydrothermal Method

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Mihaela Birdeanu ◽  
Mirela Vaida ◽  
Eugenia Fagadar-Cosma
Keyword(s):  
Hydrothermal Method ◽  
Isopropyl Alcohol ◽  
Monoclinic Space Group ◽  
Blue Color ◽  
The Novel ◽  
X Ray Diffraction ◽  
Transmission Microscopy ◽  
X Ray ◽  
Resolution Electron ◽  
Electron Transmission Microscopy

The present study is focused on the obtaining of the Zn3Nb2O8nanomaterial using the hydrothermal method and its characterization through different techniques. X-ray diffraction at room temperature revealed that a novel crystalline form of the nanomaterial forms at 1100°C belonging to monoclinic space group C2/c. Field-emission scanning electron microscopy evidenced the columnar morphology of the particle’s agglomeration and the high resolution electron transmission microscopy confirms the measured interplanar distances calculated from the X-ray diffraction experiments. Using the UV-VIS spectrum and Kubelka-Munk equations, the absorbance and the band gap for the Zn3Nb2O8nanomaterial were calculated. PL spectrum reveals a single peak at 465 nm corresponding to the blue color fluorescence. The novel crystalline nanomaterial might find applications in fluorescence covering of technical devices, due to its capacity to preserve blue fluorescence both in acrylic based paint and after embedding in isopropyl alcohol.

Ten-Vertex Polyhedral Monocarbaborane Chemistry. The Novel High-Yield Formation of the Ten-Vertex closo Compound [6-(PMe2Ph)-closo-1-CB9H9] from the Thermolysis of [8,8-(PMe2Ph)2-nido-8,7-PtCB9H11]

1993 ◽  
Vol 58 (12) ◽  
pp. 2924-2935 ◽  
Author(s):  
Jane H. Jones ◽  
Bohumil Štíbr ◽  
John D. Kennedy ◽  
Mark Thornton-Pett
Keyword(s):  
Nmr Spectroscopy ◽  
Diffraction Analysis ◽  
High Yield ◽  
Monoclinic Space Group ◽  
The Novel ◽  
X Ray Diffraction ◽  
Metal Centre ◽  
X Ray ◽  
Yield Formation ◽  
Boiling Toluene

Thermolysis of [8,8-(PMe2Ph)2-nido-8,7-PtCB9H11] in boiling toluene solution results in an elimination of the platinum centre and cluster closure to give the ten-vertex closo species [6-(PMe2Ph)-closo-1-CB9H9] in 85% yield as a colourles air stable solid. The product is characterized by NMR spectroscopy and single-crystal X-ray diffraction analysis. Crystals (from hexane-dichloromethane) are monoclinic, space group P21/c, with a = 903.20(9), b = 1 481.86(11), c = 2 320.0(2) pm, β = 97.860(7)° and Z = 8, and the structure has been refined to R(Rw) = 0.045(0.051) for 3 281 observed reflections with Fo > 2.0σ(Fo). The clean high-yield elimination of a metal centre from a polyhedral metallaborane or metallaheteroborane species is very rare.

Europium(II) Heptaphosphide EuP7 [1] Europium(II)heptaphosphid EuP7 [1]

1980 ◽  
Vol 35 (7) ◽  
pp. 824-831 ◽  
Author(s):  
Hans Georg von Schnering ◽  
Manfred Wittmann
Keyword(s):  
Chair Conformation ◽  
Monoclinic Space Group ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Divalent Europium ◽  
Salt Melts ◽  
Tetrahedral Environment ◽  
Mineral Acids ◽  
The Eu

The novel polyphosphide EuP7 was prepared under controlled conditions by the reaction of the elements in salt melts at 750-800 K. EuP7 forms black prismatic crystals not attacked by diluted mineral acids and bases. The thermal decomposition yields EuP3 at 700 K and in further steps EuP2, Eu3P4 and EuP, respectively. According to the crystal structure as well as the electrical, optical and magnetic properties EuP7 is a semiconductor (EG = 0.9 eV; EG (vert) = 1.1 eV) with divalent europium (μ = 7.55 B.M.). The compound crystallizes in the monoclinic space group P21/n with a = 1148.8(7) pm, b = 570.0(3) pm, c = 1061.0(6) pm, and β= 106.08°(5); (X-ray diffraction data; 1479 hkl, R = 0.031). The P-atoms are connected (P-P) = 218.0-223.5 pm) to a 2-dimensional infinite polyanionic structure with homonuclear 3-bonded and 2-bonded P-atoms in the ratio 5:2. The polyanionic network contains P6-rings (chair conformation) as well as P8-rings and P10-rings. The Eu-atoms are bonded to 9 P-atoms (1,4,4-polyhedra) with bond distances ranging from 306.6 to 326.6 pm. The Eu-atoms complete the tetrahedral environment of the P-atoms

scholarly journals Magnetic Characterizations of Sol-Gel-Produced Mn-Doped ZnO

2010 ◽  
Vol 2010 ◽  
pp. 1-3 ◽  
Author(s):  
R. Asmatulu ◽  
H. Haynes ◽  
M. Shinde ◽  
Y. H. Lin ◽  
Y. Y. Chen ◽  
...  
Keyword(s):  
Quantum Interference ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Parent Compound ◽  
Hexagonal Structure ◽  
X Ray Diffraction ◽  
Transmission Microscopy ◽  
Resolution Electron ◽  
Ferromagnetic Character ◽  
Electron Transmission Microscopy

Nanoparticles of ZnO doped with 6 at.% Mn were produced by a sol-gel method. X-ray diffraction confirms the hexagonal structure as that of the parent compound ZnO, and high-resolution electron transmission microscopy reveals a single-crystallite lattice. Magnetic measurements using a superconducting quantum interference device indicate that about one half of the Mn2+ions follow Curie's law for paramagnetism. The remaining Mn2+ions exhibit a weak ferromagnetic character, which might be induced through canted antiferromagnetic interactions.

Crystal Structure of mer-(PMe3)-trans(PEt3)(PPri3)H-trans-Cl2Ir III at 146 K

1997 ◽  
Vol 50 (1) ◽  
pp. 75 ◽  
Author(s):  
Evert J. Ditzel ◽  
K. David Griths ◽  
Glen B. Robertson
Keyword(s):  
Structure Refinement ◽  
Monoclinic Space Group ◽  
The Novel ◽  
X Ray Diffraction ◽  
Torsion Angles ◽  
X Ray ◽  
Face To Face ◽  
Hydride Ligand ◽  
Phosphine Complex ◽  
Metal Ligand

The structure of the novel mixed-phosphine complex mer(PMe3)-trans(PEt3)(PPri3)H-trans-Cl2IrIII has been determined by single-crystal X-ray diffraction analysis at 146±3 K. Crystals are monoclinic, space group P 21/c, with a 7·414(4), b 15·073(3), c 9·796(2) Å, β 97·46(1) and Z 4. Structure refinement by constrained (2xC-C distances) full-matrix least-squares analysis (2378 unique reflections, 217 parameters) converged with R 0·049 and ωR 0·055. The PPri3 ligand is face-to-face configured with the unique Pri group eclipsing the hydride ligand. The PEt3 ligand is asymmetrically configured with Ir-P-C-C torsion angles 174, –72 and –146°. Metal{ligand distances are: Ir{P(1,2,3) 2·366(4), 2·372(4), 2·306(4) Å; Ir-Cl(1,2) 2·386(4), 2·372(4) Å. The P-Ir-P(trans) angle is 157·2(1)°.

scholarly journals A novel layered aluminophosphate with corner-sharing AlO6chains

2014 ◽  
Vol 70 (a1) ◽  
pp. C993-C993
Author(s):  
Fernando Cámara ◽  
Linda Pastero ◽  
Rossella Arletti ◽  
Monica Cagnoni
Keyword(s):  
Raman Spectroscopy ◽  
Hydrogen Bonding ◽  
Sol Gel ◽  
Two Dimensions ◽  
Stability Field ◽  
Monoclinic Space Group ◽  
The Novel ◽  
X Ray Diffraction ◽  
In Situ Raman Spectroscopy ◽  
X Ray

The synthesis, Raman spectroscopy and crystal structure of a novel layered aluminophosphate is described. The new phase was derived by the sol-gel method starting from a modified low hydrothermal ALPO4-34 zeolite synthesis procedure[1].The structure was solved by direct methods using single-crystal X-ray diffraction. The synthesized layered material, with composition [AlPO3(OH)F(H2O)]-(H9C4ON), crystallizes in the monoclinic space group P21/a with a = 9.2282(5) Å, b = 6.9152(4) Å, c = 14.4615(9) Å, β = 101.57(1)0. Layered aluminophosphates with AlO6polyhedra have been previously described [2], although in these compounds Al octahedral share edges. The novel compound has corner sharing AlO4F(H2O) chains along [010], where fluorine is at the shared apex, four oxygen atoms are shared with PO4tetrahedra and the fifth oxygen is a H2O group. This kind of aluminophosphate chains is found in nature in tancoite [3]. Chains are linked along [100] through corner sharing with a PO4group of the adjacent chain plus hydrogen bonding of the H2O group. Layers are stacked along c* through hydrogen bonding with a double layer of morpholine (H9C4ON) molecules. The chemical stability field of the novel materialis strongly dependent from the fluorine/aluminum ratio of the starting gel. At lower fluorine concentrations only ALPO4-34 and/or AlPO4(berlinite) are stable depending on the morpholine content. Crystals growth morphology depends on the supersaturation conditions of the starting gel: at low concentrations crystals are well developed hexagonal like plate shaped and are very thin. At higher concentrations they show a more elongated morphology. A treatment with H2CO3leads to a complete morpholine removal, as shown by in situ Raman spectroscopy. Powder X-ray diffraction reveals that after morpholine extraction, the material diffract still coherently in two dimensions while a strong broadening is shown for basal planes.

Synthesis and crystallographic data of a new copper phosphate CuPO4H⋅0.5H2O

2003 ◽  
Vol 18 (1) ◽  
pp. 36-37
Author(s):  
Germa´n Alberto Sierra ◽  
Adriana Echavarria Isaza ◽  
Luz Amparo Palacio ◽  
Carlos Saldarriaga
Keyword(s):  
Thermogravimetric Analysis ◽  
Low Temperature ◽  
Chemical Analysis ◽  
Hydrothermal Method ◽  
Crystallographic Data ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Copper Phosphate

A new copper phosphate, CuPO4H⋅0.5H2O, was synthesized using a low temperature hydrothermal method and characterized by powder X-ray diffraction, thermogravimetric analysis, and chemical analysis. The material is monoclinic, space group P21/c, with a=10.6524(2), b=8.4730(2), c=9.2204(2), β=92.43(0), and V=831.47 Å3.

Hingganite-(Nd), Nd2□Be2Si2O8(OH)2, a new gadolinite-supergroup mineral from Zagi Mountain, Pakistan

2020 ◽  
Vol 58 (5) ◽  
pp. 549-562
Author(s):  
Anatoly V. Kasatkin ◽  
Fabrizio Nestola ◽  
Radek Škoda ◽  
Nikita V. Chukanov ◽  
Atali A. Agakhanov ◽  
...  
Keyword(s):  
New Mineral ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Average Chemical Composition ◽  
X Ray ◽  
Conchoidal Fracture ◽  
Icp Ms ◽  
Optical Axes ◽  
Mohs Hardness ◽  
Khyber Pakhtunkhwa Province

ABSTRACT Hingganite-(Nd), ideally Nd2□Be2Si2O8(OH)2, is a new gadolinite group, gadolinite supergroup mineral discovered at Zagi Mountain, near Kafoor Dheri, about 4 km S of Warsak and 30 km NW of Peshawar, Khyber Pakhtunkhwa Province, Pakistan. The new mineral forms zones measuring up to 1 × 1 mm2 in loose prismatic crystals up to 0.7 cm long, where it is intergrown with hingganite-(Y). Other associated minerals include aegirine, microcline, fergusonite-(Y), and zircon. Hingganite-(Nd) is dark greenish-brown, transparent, has vitreous luster and a white streak. It is brittle and has a conchoidal fracture. No cleavage or parting are observed. Mohs hardness is 5½–6. Dcalc. = 4.690 g/cm3. Hingganite-(Nd) is non-pleochroic, optically biaxial (+), α = 1.746(5), β = 1.766(5), γ = 1.792(6) (589 nm). 2Vmeas. = 80(7)°; 2Vcalc. = 84°. Dispersion of optical axes was not observed. The average chemical composition of hingganite-(Nd) is as follows (wt.%; electron microprobe, BeO, B2O3, and Lu2O3 content measured by LA-ICP-MS; H2O calculated by stoichiometry): BeO 9.64, CaO 0.45, MnO 0.10, FeO 3.03, B2O3 0.42, Y2O3 8.75, La2O3 1.63, Ce2O3 12.89, Pr2O3 3.09, Nd2O3 16.90, Sm2O3 5.97, Eu2O3 1.08, Gd2O3 5.15, Tb2O3 0.50, Dy2O3 2.50, Ho2O3 0.33, Er2O3 0.84, Tm2O3 0.10, Yb2O3 0.44, Lu2O3 0.04, ThO2 0.13, SiO2 23.55, H2O 2.72, total 100.25. The empirical formula calculated on the basis of 2 Si apfu is (Nd0.513Ce0.401Y0.395Sm0.175Gd0.145Pr0.096Dy0.068La0.051Ca0.041Eu0.031Er0.022Tb0.014Yb0.011Ho0.009Tm0.003Th0.003Lu0.001)Σ1.979(□0.778Fe2+0.215Mn0.007)Σ1.000(Be1.967B0.062)Σ2.029Si2O8.46(OH)1.54. Hingganite-(Nd) is monoclinic, space group P21/c with a = 4.77193(15), b = 7.6422(2), c = 9.9299(2) Å, β = 89.851(2)°, V = 362.123(14) Å3, and Z = 2. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 6.105 (95) (011), 4.959 (56) (002), 4.773 (100) (100), 3.462 (58) (102), 3.122 , 3.028 (61) (013), 2.864 (87) (121), 2.573 (89) (113). The crystal structure of hingganite-(Nd) was refined from single-crystal X-ray diffraction data to R = 0.034 for 2007 unique reflections with I > 2σ(I). The new mineral is named as an analogue of hingganite-(Y), hingganite-(Yb), and hingganite-(Ce), but with Nd dominant among the rare earth elements.

Role of the Structure and Electronic Properties of Fe2O3-MoO3 Catalyst on the Dehydration of Isopropyl Alcohol

1993 ◽  
Vol 58 (7) ◽  
pp. 1591-1599 ◽  
Author(s):  
Abd El-Aziz A. Said
Keyword(s):  
Active Sites ◽  
Isopropyl Alcohol ◽  
Oxide Catalyst ◽  
Flow System ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalyst Composition ◽  
Surface Active

Molybdenum oxide catalyst doped or mixed with (1 - 50) mole % Fe3+ ions were prepared. The structure of the original samples and the samples calcined at 400 °C were characterized using DTA, X-ray diffraction and IR spectra. Measurements of the electrical conductivity of calcined samples with and without isopropyl alcohol revealed that the conductance increases on increasing the content of Fe3+ ions up to 50 mole %. The activation energies of charge carriers were determined in presence and absence of the alcohol. The catalytic dehydration of isopropyl alcohol was carried out at 250 °C using a flow system. The results obtained showed that the doped or mixed catalysts are active and selective towards propene formation. However, the catalyst containing 40 mole % Fe3+ ions exhibited the highest activity and selectivity. Correlations were attempted to the catalyst composition with their electronic and catalytic properties. Probable mechanism for the dehydration process is proposed in terms of surface active sites.

scholarly journals Some Novel Cobalt Diphenylphosphine Complexes: Synthesis, Characterization, and Behavior in the Polymerization of 1,3-Butadiene

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4067
Author(s):  
Giovanni Ricci ◽  
Giuseppe Leone ◽  
Giorgia Zanchin ◽  
Benedetta Palucci ◽  
Alessandra Forni ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
And Behavior

Some novel cobalt diphenylphosphine complexes were synthesized by reacting cobalt(II) chloride with (2-methoxyethyl)diphenylphosphine, (2-methoxyphenyl)diphenylphosphine, and 2-(1,1-dimethylpropyl)-6-(diphenylphosphino)pyridine. Single crystals suitable for X-ray diffraction studies were obtained for the first two complexes, and their crystal structure was determined. The novel compounds were then used in association with methylaluminoxane (MAO) for the polymerization of 1,3-butadiene, and their behavior was compared with that exhibited in the polymerization of the same monomer by the systems CoCl2(PnPrPh2)2/MAO and CoCl2(PPh3)2/MAO. Some significant differences were observed depending on the MAO/Co ratio used, and a plausible interpretation for such a different behavior is proposed.

scholarly journals High-pressure synthesis of REB5O8(OH)2 (RE = Ho, Er, Tm)

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Michael Zoller ◽  
Hubert Huppertz
Keyword(s):  
High Pressure ◽  
Rare Earth ◽  
Ir Spectroscopy ◽  
Earth Metal ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Solution ◽  
Pressure Synthesis ◽  
The Rare Earth

AbstractThe rare earth oxoborates REB5O8(OH)2 (RE = Ho, Er, Tm) were synthesized in a Walker-type multianvil apparatus at a pressure of 2.5 GPa and a temperature of 673 K. Single-crystal X-ray diffraction data provided the basis for the structure solution and refinement. The compounds crystallize in the monoclinic space group C2 (no. 5) and are composed of a layer-like structure containing dreier and sechser rings of corner sharing [BO4]5− tetrahedra. The rare earth metal cations are coordinated between two adjacent sechser rings. Further characterization was performed utilizing IR spectroscopy.

Sign in / Sign up

Export Citation Format

Share Document