The Experts below are selected from a list of 42 Experts worldwide ranked by ideXlab platform
Alain Cousson - One of the best experts on this subject based on the ideXlab platform.
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neutron structural x ray powder and vibrational studies of the mixed solid solution rubidium ammonium sulfate tellurate
Journal of Alloys and Compounds, 2009Co-Authors: L Ktari, M Dammak, A W Kolsi, Alain CoussonAbstract:Abstract At room temperature the rubidium ammonium sulfate tellurate salt Rb 1.12 (NH 4 ) 0.88 SO 4 ·Te(OH) 6 (RbNST) has been prepared using the reaction of the rubidium sulfate, ammonium sulfate and Telluric Acid. Its structure has been determined from single crystal using neutron diffraction data. The RbNST crystal is monoclinic structure with P 2 1 / a space group. The parameters are: a = 11.440(9) A, b = 6.640(7) A, c = 13.700(1) A, β = 106.90(7)° and Z = 4. The main result is the presence of two different and independent anionic groups (TeO 6 6− and SO 4 2− ) in the same crystal. The structure is like built by planes of pure SO 4 tetrahedra and pure TeO 6 octahedra altering with Rb + and NH 4 + cations statistically disordered on one atomic position. Differential scanning calorimetry traces show one anomaly at 418 K, two epaulments at 483 and 510 K corresponding to three phase transitions and one strong peak at 517 K dealing with the decomposition of the salt. Raman scattering and X-ray powder diffraction measurements on RbNST material, taken between 300 and 620 K are reported in this paper. The spectrums confirm and characterize clearly these phase transitions detected by DSC.
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The solid solution Na0.39(NH4)1.61SO4·Te(OH)6
International Union of Crystallography, 2008Co-Authors: Abdelwaheb Kolsi, Alain Cousson, Mohamed Dammak, Mohamed Abdelhedi, Lilia KtariAbstract:The title compound, sodium ammonium sulfate–Telluric Acid (1/1), Na0.39(NH4)1.61SO4·Te(OH)6, is isostructural with other solid solutions in the series M1−x(NH4)xSO4·Te(OH)6, where ammonium is partially replaced with an alkali metal (M = K, Rb or Cs). The structure is composed of planes of Te(OH)6 octahedra alternating with planes of SO4 tetrahedra. The Na+/NH4+ cations are statistically distributed over the same position and are located between the planes. The structure is stabilized by O—H...O and N—H...O hydrogen bonds between the Telluric Acid adducts and the O atoms of sulfate groups, and between the ammonium cations and O atoms, respectively. Both Te atoms lie on centres of symmetry
Nikolaus Korber - One of the best experts on this subject based on the ideXlab platform.
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the first alkali metal hydroxide ammoniate cesium hydroxide ammoniate 1 1 csoh nh3 synthesis and crystal structure
Monatshefte Fur Chemie, 2013Co-Authors: Christian Guentner, Nikolaus KorberAbstract:Cesium hydroxide-ammoniate (1:1), CsOH·NH3, was obtained as a side product in the reaction of cesium hydride, CsH and Telluric Acid, Te(OH)6 in liquid ammonia at −38 °C. The compound crystallizes as colorless crystals in the monoclinic space group P21/c with Z = 8, a = 4.391(9) A, b = 18.593(4) A, c = 8.141 (16) A, β = 90.37(3)°, and V = 664.6(24) A3. The crystal structure was solved from single crystal X-ray data. The structure contains a three-dimensional network built up by contacts between cesium cations and hydroxide anions and ammonia molecules, which in turn are connected by O–H···N and N–H···O hydrogen bonds.
L Ktari - One of the best experts on this subject based on the ideXlab platform.
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neutron structural x ray powder and vibrational studies of the mixed solid solution rubidium ammonium sulfate tellurate
Journal of Alloys and Compounds, 2009Co-Authors: L Ktari, M Dammak, A W Kolsi, Alain CoussonAbstract:Abstract At room temperature the rubidium ammonium sulfate tellurate salt Rb 1.12 (NH 4 ) 0.88 SO 4 ·Te(OH) 6 (RbNST) has been prepared using the reaction of the rubidium sulfate, ammonium sulfate and Telluric Acid. Its structure has been determined from single crystal using neutron diffraction data. The RbNST crystal is monoclinic structure with P 2 1 / a space group. The parameters are: a = 11.440(9) A, b = 6.640(7) A, c = 13.700(1) A, β = 106.90(7)° and Z = 4. The main result is the presence of two different and independent anionic groups (TeO 6 6− and SO 4 2− ) in the same crystal. The structure is like built by planes of pure SO 4 tetrahedra and pure TeO 6 octahedra altering with Rb + and NH 4 + cations statistically disordered on one atomic position. Differential scanning calorimetry traces show one anomaly at 418 K, two epaulments at 483 and 510 K corresponding to three phase transitions and one strong peak at 517 K dealing with the decomposition of the salt. Raman scattering and X-ray powder diffraction measurements on RbNST material, taken between 300 and 620 K are reported in this paper. The spectrums confirm and characterize clearly these phase transitions detected by DSC.
Sahar I Mostafa - One of the best experts on this subject based on the ideXlab platform.
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cellulose derivatives modified by sodium tellurate and a chromium iii tellurate complex
International Journal of Biological Macromolecules, 2016Co-Authors: Ian S Butler, Heba Allah M Elsherbeny, I M M Kenawy, Sahar I MostafaAbstract:A novel cellulose (Cell) derivative, sodium-tellurato (Cell-TeO(OH)4(ONa)/Cell-Cl), has been synthesized from the reaction of 6-chloro-6-deoxycellulose (Cell-Cl) with Telluric Acid in the presence of sodium hydroxide. The subsequent reaction of this polymeric material with chromium(III) in aqueous solution yields the [Cr(Cell-TeO3(OH)3/Cell-Cl)(Cell-TeO2(OH)4/Cell-Cl)(H2O)3] complex. The molecular structures and morphology of the new polymer and the Cr(III) complex have been examined using elemental analysis, solid-state 13C NMR, UV–vis, XRD and FTIR spectroscopy, and SEM-EDX, TGA and magnetic measurements. The results are considered to be consistent with the formulations proposed. The deprotonation constants of the modified cellulose and the stability constant of the Cr(III) complex have been determined by pH-metric measurements.
Christian Guentner - One of the best experts on this subject based on the ideXlab platform.
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the first alkali metal hydroxide ammoniate cesium hydroxide ammoniate 1 1 csoh nh3 synthesis and crystal structure
Monatshefte Fur Chemie, 2013Co-Authors: Christian Guentner, Nikolaus KorberAbstract:Cesium hydroxide-ammoniate (1:1), CsOH·NH3, was obtained as a side product in the reaction of cesium hydride, CsH and Telluric Acid, Te(OH)6 in liquid ammonia at −38 °C. The compound crystallizes as colorless crystals in the monoclinic space group P21/c with Z = 8, a = 4.391(9) A, b = 18.593(4) A, c = 8.141 (16) A, β = 90.37(3)°, and V = 664.6(24) A3. The crystal structure was solved from single crystal X-ray data. The structure contains a three-dimensional network built up by contacts between cesium cations and hydroxide anions and ammonia molecules, which in turn are connected by O–H···N and N–H···O hydrogen bonds.
