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11.
Dr. Mamdouh S. Masoud T. M. Salem M. Elessawi 《Monatshefte für Chemie / Chemical Monthly》1978,109(1):221-227
The reactions of the bidentate dinitrosoresorcinol (DNR) with copper, cobalt, nickel, iron and zinc salts were investigated. This ligand was found to react with these metal salts in aqueous media where hydrogen ion was confirmed to be liberated except in case of iron. The solid complexes were prepared in alcoholic media. Chemical analyses, magnetic and spectral data were compatible to determine the structure of these complexes and their mode of chelation.
Mit 2 Abbildungen 相似文献
Mit 2 Abbildungen 相似文献
12.
The spectral properties of o-aminophenol, catechol, o-nitrophenol, pyrogallol, salicylic acid and gallic acid were investigated in different solvents. The behaviour of hydrogen bonding demonstrated in these systems was discussed. 相似文献
13.
Masoud MS Abou El-Enein SA Ayad ME Goher AS 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2004,60(1-2):77-87
Complexes of Co(II), Ni(II) and Cu(II) with substituted phenylazo-6-aminouracils containing (-H, p-OH, p-CH(3), p-OCH(3) p-COOH) have been synthesized and characterized by elemental analysis, magnetic measurements and spectral measurements (IR, UV-Vis, ESR). Infrared spectra assigned the fundamental bands of the major groups, O-H, N-H, C-H, C=O, C=N, N=N, C-N and C-O (nu, delta and gamma modes of vibrations). The absence of nu(OH) and the appearance of nu(C=O) in the infrared spectra of the free ligands of 5-(p-tolyl and p-anisylazo)-6-aminouracil, assigned the keto structure, whereas in cases of 5-(phenyl, p-hydroxyphenyl and p-carboxyphenylazo)-6-aminouracil ligands, the data showed strong nu(OH) and nu(C=O) bands to assign keto-enol tautomerisms. The modes of interactions between the ligands and the metals were discussed, where oxygen and nitrogen atoms (of amino-amide groups) are involved in chelation. The azo group was not involved in chelation for all the prepared complexes except those of copper complexes derived from 5-(phenyl, p-tolyl, p-hydroxyphenyl and p-carboxyphenylazo)-6-aminouracils. The room temperature effective magnetic moment values, the Nujol mull spectra and ESR proved that all the prepared complexes were of octahedral geometry, except the nickel complex derived from 5-(phenylazo)-6-aminouracil and cobalt complex derived from 5-(p-carboxy-phenylazo)-6-aminouracil were square planar. 相似文献
14.
M. S. Masoud E. A. Khalil E. El-Sayed El-Shereafy S. A. El-Enein 《Journal of Thermal Analysis and Calorimetry》1990,36(3):1033-1038
The thermal behaviour of the entitled nickel(II) and copper(II) complexes of ¯4-acetylamino-2-hydroxy-5-methyl azobenzene has been studied by means of differential thermal analysis (DTA), thermogravimetry (TG), X-ray powder diffraction, IR and electrical conductivity. A light has been thrown on the nature of interaction of the solvents of crystallization with the host complex. Some of the kinetic parameters are calculated and discussed. 相似文献
15.
The reaction of an ethanolic solution 2,6‐pyridinedicarboxylic acid ( 1 , LH2) with TlNO3 in the presence of triethylamine led to the coordination polymer [Tl(LH)]n ( 2 ). The complex was characterized by elemental analysis, IR spectroscopy and single‐crystal X‐ray diffraction. Crystal data for 2 at –80 °C: monoclinic, space group I2/a, a = 696.1(1), b = 1190.6(2), c = 931.0(2) pm, β = 103.28(1)°, Z = 4, R1 = 0.0256. 相似文献
16.
M. I. El-Barghouthi N. A. Masoud J. K. Al-Kafawein M. B. Zughul A. A. Badwan 《Journal of inclusion phenomena and macrocyclic chemistry》2005,53(1-2):15-22
The solubility of risperidone (Risp) in aqueous buffered cyclodextrin (CD) solution was investigated for α-, β-, γ- and HP-β-CD. The effects of pH, ionic strength and temperature on complex stability were also explored. Neutral Risp tends to form
higher order complexes (1:2) with both β- and HP-β-CD, but only 1:1 type complexes with α-, and γ-CD. The tendency of Risp to complex with cyclodextrins is in the order β-CD > HP-β-CD > γ-CD > α-CD. The 1:1 complex formation constant of Risp/HP-β-CD increases with increasing ionic strength in an opposite trend to the inherent solubility (S
0) of Risp, thus indicating significant hydrophobic effect. The hydrophobic effect contributes to the extent of 72% towards
neutral Risp/HP-β-CD complex stability, while specific interactions contribute only 4.7 kJ/mol. Thermodynamic studies showed that 1:1 Risp/HP-β-CD complex formation is driven by a favorable enthalpy change (ΔH
0=−31.2 kJ/mol, ΔS
0=−7 J/mol.K) while the 1:2 complex is largely driven by entropy changes (ΔH
0=−5.0 kJ/mol, ΔS
0=42 J/mol.K). Complex stability was found to vary with pH, with a higher formation constant for neutral Risp. Molecular mechanical
computations using MM (atomic charges and bond dipole algorithms) and Amber force fields, which were carried out to explore
possible sites of interactions between Risp and CDs and to rationalize complex stoichiometry, produced similar results concerning
optimal inclusion complex geometries and stoichiometries. 相似文献
17.
The potentiometric response properties and applications of a tetra-coordinate nickel(II) complex with relatively high selectivity toward nitrate ion are described. The nickel(II) complex of 5,7,12,14-tetramethyl-1,4,8,11-tetraazacyclotetradeca-4,6,11,13-tetraene was used as a neutral carrier into plasticized poly(vinyl chloride) (PVC) membrane. The influence of several variables was investigated in order to optimize the potentiometric response and selectivity of the electrode. The resulting membrane electrode incorporating 31.0% PVC, 61.0% dioctyl phthalate (DOP) as plasticizer, 3% methyltrioctylammonium chloride (MTOAC) as a cationic additive and 5% carrier (all w/w) demonstrates a Nernstian response slope of −59.6 mV per decade over the concentration range of 5×10−6-1×10−1 M NO3−. The electrode exhibits a fast response time (≤10 s), a detection limit of 2.5×10−6 M, and can be used over a wide pH range of 4-12. The electrode shows improved selectivity in comparison to most of the previously reported nitrate-selective electrodes. It was successfully applied to the determination of nitrate ion in natural water samples. 相似文献
18.
The reaction of 2,6‐pyridinedicarboxylic acid ( 1 , LH2) with CeCl3·7H2O and Sm(NO3)3·6H2O in the presence of triethylamine led to the coordination polymer complexes [M(L)(LH)(H2O)2]·4H2O [M = Ce ( 2 ) and Sm ( 3 )]. Both complexes were characterized by elemental analyses, IR spectroscopy and the crystal structures of 2 and 3 . Crystal data for 2 at ?80 °C: monoclinic, space group P21/c, a = 1404.6(1), b = 1122.1(1), c = 1296.1(1) pm, β = 102.09(1)°, Z = 4, R1 = 0.0217 and for 3 at ?80 °C: monoclinic, space group P21/c, a = 1395.1(1), b = 1120.1(1), c = 1282.8(1) pm, β = 102.71(1)°, Z = 4, R1 = 0.019. 相似文献
19.
Alfy Badie Sakla Nabil Khalil Masoud Zaki Sawiris Wagih Sadik Ebaid 《Helvetica chimica acta》1974,57(2):481-487
Aryldiazophenyl sulfides prepared from diazotised arylamines and thiophenol at controlled pH, are coupled with β-naphthol yielding the corresponding azo dye. A kinetic study of the diazo coupling reaction of p-nitrobenzenediazo phenyl sulfide with β-naphthol under various conditions revealed that the reaction is of first order kinetics with respect to the diazo phenyl sulfide, and that the rate of coupling measured colorimetrically is influenced by the hydrogen ion concentration and by the ionising power of the medium. 相似文献
20.
Nabavizadeh SM 《Dalton transactions (Cambridge, England : 2003)》2005,(9):1644-1648
Methyltrioxorhenium (MTO) adduct formation with bidentate nitrogen donors 2,2'-bipyridine (bpy), 4,4'-dimethyl-2,2'-bipyridine (Me(2)bpy), 4,4'-di-tert-butyl-2,2'-bipyridine (tBu2bpy), 1,10-phenanthroline (phen), 5-methyl-1,10-phenanthroline (5-Mephen), 5-chloro-1,10-phenanthroline (5-Clphen), 4,7-dimethyl-1,10-phenanthroline (Me2phen) has been studied at different temperatures in CHCl3 solution. Spectrophotometeric measurements have been carried out to obtain the thermodynamic parameters. All complexes are enthalpy stabilized whereas the entropy changes counteract the adduct formation. The results are discussed in terms of different basicities of the bidentate N-donors. 相似文献