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551.
Summary Transition metal complexes of cobalt(II), nickel(II), copper(II) and palladium(II) with 3-amino-4-(arylazo)-5-(1H)pyrazolones (Aryl=Ph, 4-C6H4CO2H, 4-C6H4-OMe, 3-C6H4Cl, 3-C6H4CO2H, 3-C6H4NO2, 3-C6H4-Me, 3-C6H4OH and 2-C6H4CO2H) are discussed. The stoichiometry of the complexes is: 11, 23 CoII; 11 NiII; 11, 21 CuII and 12 PdII. The investigations suggest rhombic symmetry with 4- or 5-coordinate CoII, square planar and tetrahedral configuration for NiII, tetrahedral CuII and square planar for PdII complexes. The complexes contain no anions. 相似文献
552.
On the perspectives of capillary electrophoresis modes for the determination of morphine in human plasma without sample pretreatment 总被引:1,自引:0,他引:1
Screening and confirmation of drugs of abuse in body fluids are important for the medicinal treatment and form the legal basis of court judgments. A fast and precise identification of toxic substances is necessary. Morphine was determined in human plasma by capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MECC) using sample stacking mode. The electrophoretic separation was performed in an uncoated fused-silica capillary, 70 cm long to the detector, with an additional 10 cm to the cathode (75 microm i.d. and 360 microm o.d.). The UV absorbance detection was set at 190 nm. The electrophoretic buffers were prepared from 60 to 300 mm disodium tetraborate decahydrate, pH 10.5. Sodium dodecyl sulfate was added to the final solution in a concentration of 60 mm for MECC. All electrophoretic separations were carried out at 10 kV and the capillary temperature was ambient (25 degrees C). A linear calibration graph was obtained in the concentration range studied (50-5000 ng/mL). Several samples of drug-free plasma were checked for potential endogenous interference and the results showed no interference from the endogenous components, which co-migrated with morphine. As little as 50 ng/mL of morphine could be successfully analyzed by MECC in the concentration mode with acceptable precision. It is possible to determine morphine directly in plasma at therapeutic concentrations. 相似文献
553.
Kamal A. Kandeel Ali M. Youssef Hany M. El-Bestawy Mohamed T. Omar 《Monatshefte für Chemie / Chemical Monthly》2002,133(9):1211-1219
Summary. N,N-Disubstituted 5-arylmethylidene-2-aminothiazol-4(5H)-ones reacted with diethyl malonate, ethyl benzoylacetate, acetylacetone, or cyclopentadiene in refluxing toluene and in
presence of powdered sodium to give the respective 5-arylmethylidene-2′-amino-2,5′-bithiazolylidene-4,4′-dione derivatives
in moderate yields. 5-Benzylidene-2-morpholin-4-yl-2-thiazol-4(5H)-one reacted with malononitrile in toluene and in presence of powdered sodium under mild conditions to afford the 1:1 adduct,
benzylmalononitrile, and 2-morpholin-4-yl-2-thiazol-4(5H)-one. However, similar treatment of 5-(4-methoxyphenylmethylidene)-2-morpholin-4-yl-2-thiazol-4(5H)-one with malononitrile yielded the 2,5′-bithiazolylidene-4,4′-dione derivative together with 4-methoxyphenylmethylidene
malononitrile. Treatment of 5-benzylidene- and 5-(4-methoxyphenylmethylidene)-2-morpholin-4-yl-2-thiazol-4(5H)-ones with 3-phenyl-4-oxo-2-thioxo-1,3-thiazolidine in refluxing toluene and in presence of powdered sodium produced 5-arylmethylidene-3-phenyl-4-oxo-2-thioxo-1,3-thiazolidines
in good yields. The structures of all products were deduced from microanalytical and spectroscopic data, mechanistic details
are discussed.
Corresponding author. E-mail: kamalkandeel@hotmail.com
Received November 5, 2001. Accepted (revised) December 17, 2001 相似文献
554.
B. Boutevin Y. Pietrasanta B. Youssef 《Journal of polymer science. Part A, Polymer chemistry》1987,25(11):3025-3038
The addition by redox catalysis (CuCl or FeCl3 with benzoin) of CCl4 and CCl3? CF2? CCl3 on pentafluorostyrene and on fluorinated allyl ether, C6F13? C2H4? O? CH2? CH?CH2 was performed. The monoaddition compounds were mainly obtained with satisfactory yields and characterized by NMR (13C, 1H, and 19F). These compounds were then used as telogens in telomerization by redox catalysis of acrylamide, methyl methacrylate, and acrylic acid and in radical-initiated telomerization of N-vinyl-pyrrolidone. The chain lengths of the hydrocarbonated sequences were determined from fluorine elemental analysis. A critical investigation of correlations between DP n and concentrations of products involved was made. 相似文献
555.
E. Saab S. Aouad E. Abi-Aad M. N. Bokova E. A. Zhilinskaya A. Aboukaïs 《Kinetics and Catalysis》2007,48(6):841-846
The catalytic combustion of carbon black was investigated in the presence of CeO2 and Al2O3. The influence of contact type between carbon particles and these oxides was examined by thermal analysis, the BET specific
area, and EPR spectroscopy. For tight contact carbon black-catalyst mixtures, a new paramagnetic species is observed and can
be considered as a fingerprint of the contact between the two solids. These new paramagnetic species increase the reactivity
of the catalytic reaction of carbon black (CB) combustion and take part in the oxidation mechanism of CB.
Published in Russian in Kinetika i Kataliz, 2007, Vol. 48, No. 6, pp. 899–904.
This article was submitted by the authors in English. 相似文献
556.
M. S. K. Youssef S. A. M. Metwally M. A. El-Maghraby M. I. Younes 《Journal of heterocyclic chemistry》1984,21(6):1747-1752
1-Phenyl-3-methyl-5-pyrazolone-4-oxime reacted with benzylamine, methylamine, methyl- and ethyl ioides to give 3-methyl-1,5-diphenyl-1H-, 3-methyl-1-phenyl-1H- and 3,5-dimethyl-1-phenyl-1H-pyrazolo[4,3-d]oxazoles I, II. The structure of I was elucidated authentically through other routes by interaction of 1-phenyl-3-methyl-4,5-dioxopyrazolone with benzylamine and/or benzaldehyde and ammonium acetate. Various 3-meth-yl-5-aryl-1-phenyl-1H-pyrazolo[4,3-d]oxazoles IV were synthesized by the reaction of 4,5-dioxopyrazolone with aromatic aldehydes in the presence of ammonium acetate. Also, the structure of I was elucidated authentically via other routes by the reaction of 1-phenyl-3-methyl-4-imino-5-pyrazolone with each of benzylcyanide, benzylamine, benzaldehyde and benzalaniline. 相似文献
557.
The present paper reviews in detail the different studies now being conducted by our research team concerning the ultradeep hydrodesulfurization (HDS) of dibenzothiophene (DBT) derivatives over Mo/TiO2 and Mo/TiO2–Al2O3 catalysts. First, a detailed characterization of Mo/TiO2 (P-25 Degussa, 50 m2/g) catalysts prepared by equilibrium adsorption technique shows that Mo- species are highly and uniformly dispersed on the surface of titania up to 6.6 wt% MoO3 loading. Above this value, some aggregation of Mo occurs, leading to the formation of bulk MoO3. Below 6.6 wt% MoO3 loading, the Raman spectroscopy data of the calcined samples show that the supported Mo-species possess a highly distorted octahedral MoO6 structure. TiO2–Al2O3 composites were prepared by chemical vapor deposition (CVD) using TiCl4 as a precursor. Using several characterization techniques, we demonstrated that the support composite presents a high dispersion of TiO2 over -Al2O3 without forming precipitates up to ca. 11 wt% loading. Moreover, the textural properties of the composite support are comparable to those of alumina. Under the present sulfidation conditions (673 K, 5%H2S/95%H2), Mo-species supported on TiO2 are better sulfided than on alumina, as demonstrated using XPS. This can be attributed to the relatively lower interaction between Mo-species and titania. The state of sulfide species supported on the composite support can be considered as a transition state between TiO2 and Al2O3. However, at relatively higher TiO2 loadings (ca. 11 wt%), Mo/TiO2–Al2O3 catalysts exhibit sulfidability similar to that of Mo/TiO2. The HDS tests conducted in both the laboratory and in industry show that sulfide catalysts supported on TiO2–Al2O3 (ca. 11 wt% TiO2) are more active than those supported on TiO2 or Al2O3. 相似文献
558.
Amal Feddouli Moulay Youssef Ait Itto Aïssa Hasnaoui Didier Villemin Paul‐Alain Jaffrs Jana Sopkova‐De Oliveira Santos Abdelkhalek Riahi FranOis Huet Jean‐Claude Daran 《Journal of heterocyclic chemistry》2004,41(5):731-735
Herein we report an efficient one pot synthesis of new chiral 4,5‐dihydro‐4‐arylspiro[1,3,4‐thiadiazole]‐5,2′‐camphane‐2‐carboxylic acid ethyl esters 5–7 and 4,5‐dihydro‐3‐arylspiro[1,4,2‐oxathiazole]‐5,2′‐camphane 11–13 , using 1,3‐dipolar cycloaddition of nitrilimines 2–4 and nitrile oxides 8–10 to (1R)‐thiocamphor 1 respectively. The structure of the newly prepared 1,3,4‐thiadiazoles 5–7 (obtained as pure diastereoisomers) were fully established via spectroscopic analysis and X‐ray structural analysis which proved the absolute configuration of the C5 spiranic carbon to be (R). NMR spectral analysis were also very useful to show the new 1,4,2‐oxathiazoles 11–13 are mixtures of two (5R)/(5S) diastereoisomers with the ratio 6:4,7:3 and 6:4 respectively. 相似文献
559.
Nabil L. Youssef S. H. Abed A. Soleiman 《Rendiconti del Circolo Matematico di Palermo》1936,60(1-2):263-281
The aim of the present paper is to provide an intrinsic investigation of projective changes in Finsler geometry, following the pullback formalism. Various known local results are generalized and other new intrinsic results are obtained. Nontrivial characterizations of projective changes are given. The fundamental projectively invariant tensors, namely, the projective deviation tensor, the Weyl torsion tensor, the Weyl curvature tensor and the Douglas tensor are investigated. The properties of these tensors and their interrelationships are obtained. Projective connections and projectively flat manifolds are characterized. The present work is entirely intrinsic (free from local coordinates) (arXiv:?0904.?1602 [math.DG]). 相似文献
560.
AbstractThe elastic field generated by a semi-coherent interface formed by a succession of parallel terraces and nanoledges is investigated when the interface intersects the free surface of an isotropic half-space medium. The method uses the combination of semi-infinite Somigliana dislocations placed on each terrace and semi-infinite translation (or Volterra) dislocations placed at one or two corners of the nanoledges. Numerical examples depict the deformation fields nearby emerging regions of two semi-coherent interfaces; one is flat, while the other includes nanoledges. 相似文献