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31.
F.H. El-Sweify A.A. Abdel-Fattah S.M. Ali 《The Journal of chemical thermodynamics》2008,40(5):798-805
Thermodynamic studies on solvent extraction of Th(IV) have been carried out using TBP and HDEHP as extractants in toluene from aqueous bromide and iodide media containing Arsenazo-III as a colouring reagent. This reagent was used for the spectrophotometric determination of Th(IV). The study was carried out at T = {(283, 298, 313) ± 1} K to evaluate lg Kex as well as the thermodynamic functions ΔG°, ΔH°, and ΔS° of the extraction reactions. The extracted species and the overall extraction mechanisms are postulated. 相似文献
32.
Alan R. Katritzky Ashraf A.A. Abdel-Fattah Krzysztof R. Idzik Bahaa El-Dien M. El-Gendy Jadwiga Soloducho 《Tetrahedron》2007,63(28):6477-6484
Reactions of readily available and stable 1-(α-alkoxyalkyl)benzotriazoles type 9a,b and 10a-d with a variety of silyl enol ethers 11 or 1,3-dicarbonyl compounds 13 give the expected ketones 12a-l (60-92%), β-keto esters 14a,b (62-67%), and malonates 14c,d (79-88%) in which a tetrahydrofuran or tetrahydropyran moiety has been introduced at the α position. 1-(Benzotriazol-1-yl)alkyl esters 7 are converted by cyanide anion into cyanohydrin esters 15a-i (55-98%). 相似文献
33.
A. A. Abdel-Fattah S. M. Ali F. H. El-Sweify 《Journal of Radioanalytical and Nuclear Chemistry》2002,253(3):465-475
Solvent extraction on Zr(IV) were carried out at 5, 25 and 40 °C using Amberlite LA-2, TBP and HDEHP in toluene or kerosene from solutions of HCl, HBr or KI. The equilibrium constant K
ex as well as the thermodynamic functions DG°, DH° and DS° of the nine extraction systems were deduced. The overall extraction equilibria were postulated from the obtained data. 相似文献
34.
Al-Shihri A. S. M. Abdel-Fattah H. M. 《Journal of Thermal Analysis and Calorimetry》2003,71(2):643-649
Solid complexes of two derivatives of Schiff bases SAT and SAZ with Pr(III), Nd(III), Gd(III), Dy(III), Ho(III), Er(III) and
Yb(III) were prepared and characterized by elemental analysis , IR spectra and TG. The suggested formula of the obtained solid
complexes is [MLCl2(H2O)n] for sat and [MLCl (H2O)n] for SAZ where M=trivalent lanthanide ion, L=deprotonated ligand and n=2-3. The TG gives information about the coordinated water molecules, thermal stability and the coordination number of M which was found to be 6–8. A scheme of thermal decomposition of the complexes is also proposed. Comparison of the IR spectra
of the ligands with those of their complexes indicate the center of chelation in SAT and SAZ which act as tridentate ligands.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
35.
Preparation, Spectroscopic and Crystal Structure Investigations of [Cl4SbO2P(CH3)2]2 [Cl4SbO2P(CH3)2]2 was prepared from SbCl5 and HOP(O)(CH3)2 in CH2Cl2. The compound crystallizes in the space group P21/n with two dimeric units per unit cell; the lattice constants are a = 875, b = 1306, c = 923 pm and β 97.1°. Structural investigation by X-ray diffraction methods showed the Sb atoms in the dimeric units to be linked by O? P? O-bridges of the dimethylphosphinate groups to Sb2O4P2 eight-rings of approximate symmetry C2h. The vibrational spectrum (i.r., Raman) and the n.m.r. spectra (31P, 1H) consist with this structure. 相似文献
36.
Abdel-Fattah A. Moussa 《Mikrochimica acta》1982,77(3-4):169-174
Summary The USP method for the determination of pyridoxine hydrochloride in pharmaceutical preparations has been modified to increase the stability of the colour, the speed of determination and the sensitivity. The reaction is carried out in propan-2-ol medium instead of water triethanolamine is used as the buffer, and iodine is used as oxidant when necessary. The colour is stable for about 45 min, the sensitivity of the reaction is greatly increased and the method takes only about a fifth of the time of the USP method.
Kolorimetrische Bestimmung von Pyridoxin in pharmazeutischen Präparaten
Zusammenfassung Die USP-Methode zur Bestimmung von Pyridoxinhydrochlorid in pharmazeutischen Präparaten wurde modifiziert, um die Beständigkeit der Farbe, die Geschwindigkeit der Bestimmung und deren Empfindlichkeit zu verbessern. Statt in Wasser wird die Reaktion in Propan-2-ol durchgeführt, wobei Triethanolamin als Puffer und Jod — wenn nötig — als Oxydationsmittel verwendet werden. Die Farbe ist ungefähr 45 min beständig, die Empfindlichkeit der Reaktion stark verbessert und die zur Durchführung der Methode erforderliche Zeit beträgt etwa ein Fünftel im Vergleich zur USP-Methode.相似文献
37.
The complexes cis‐[SnCl4(H2O)2]·2H2O ( 1 ), [Sn2Cl6(OH)2(H2O)2]·4H2O ( 3 ), and [HL][SnCl5(H2O)]·2.5H2O ( 4 ) were isolated from a CH2Cl2 solution of equimolar amounts of SnCl4 and the ligand L (L=3‐acetyl‐5‐benzyl‐1‐phenyl‐4, 5‐dihydro‐1, 2, 4‐triazine‐6‐one oxime, C18H18N4O2) in the presence of moisture. 1 crystallizes in the monoclinic space group Cc with a = 2402.5(1) pm, b = 672.80(4) pm, c = 1162.93(6) pm, β = 93.787(6)° and Z = 8. 4 was found to crystallize monoclinic in the space group P21, with lattice parameters a = 967.38(5) pm, b = 1101.03(6) pm, c = 1258.11(6) pm, β = 98.826(6)° and Z = 2. The cell data for the reinvestigated structures are: [SnCl4(H2O)2]·3H2O ( 2 ): a = 1227.0(2) pm, b = 994.8(1) pm, c = 864.0(1) pm, β = 103.86(1)°, with space group C2/c and Z = 4; 3 : a = 961.54(16) pm, b = 646.29(7) pm, c = 1248.25(20) pm, β = 92.75(1)°, space group P21/c and Z = 4. 相似文献
38.
39.
Mohamed Abdel Maaboud Ismail Mohamed Fardous Abdel-Fattah Ahmed Sameh Abdel-Raouf Mohamed Yahya Abduh Salim 《平面色谱法杂志一现代薄层色谱法》2013,26(3):209-214
JPC – Journal of Planar Chromatography – Modern TLC - New sensitive and selective HPTLC-densitometric method has been developed for the determination of pioglitazone hydrochloride. The... 相似文献
40.
H. M. Abdel-Fattah A. L. El-Ansary N. S. Abdel-Kader 《Journal of Thermal Analysis and Calorimetry》2009,96(3):961-969
Several new complexes of Schiff bases ligands H4La and H4Lb with transition metal ions such as Cr(III), Fe(III), Co(II) and Zn(II) are synthesized. Elemental analysis, infrared, UV–Vis
and thermal analysis, as well as conductivity and magnetic susceptibility measurements are used to elucidate the structure
of the newly prepared metal complexes. A square planar geometry is suggested for Zn(II) complexes, while an octahedral geometry
suggested for the Cr(III), Fe(III) and Co(II) complexes. The thermal decomposition of complexes was found to be first order
reaction and the thermodynamic parameters corresponding to the different decomposition steps were reported. 相似文献