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101.
Four new Hofmann–3-phenylpropylamine (3PPA) type complexes with chemical formulae M(3PPA)2Ni(CN)4 (M = Ni, Co, Cd, and Pd) have been prepared and their vibrational spectra are reported in the region of 4000–60 cm−1. The vibrational bands arising from 3PPA ligand molecule, the polymeric sheet and metal–ligand bands of the compounds are assigned. The thermal behaviour of these complexes is also provided using the DTA and TGA along with the magnetic susceptibility data. The results indicate that the monodentate 3PPA ligand molecule bonds to the metal atom of |M–Ni(CN)4|∞ polymeric layers and hence the compounds are similar in structure to Hofmann-type complexes. 相似文献
102.
The transfer of heavy metal ions across the polarized water/1,2‐dichloroethane (1,2‐DCE) interface assisted by 9‐ethyl‐3‐carbazolecarboxaldehyde‐thiosemicarbazone (ECCAT) in the 1,2‐DCE phase has been studied by cyclic voltammetry. Voltammetric waves of Pb(II) and Cd(II) ions were reversible and quasi‐reversible, respectively, whereas that of Hg(II) and Zn(II) ion were irreversible. The voltammogram of Cu(II) ion showed a two‐step wave, however the nature of the transfer could not be satisfactorily evaluated by analyzing the cyclic voltammetric data. When Ni(II) and Co(II) was used no peak was visible under the experimental conditions used in this study. The dependence of the half‐wave potentials of Pb(II) and Cd(II) ions on the ligand concentration reveals that their ion‐transfer is assisted by the formation of 1:3 metal‐ECCAT complex in 1,2‐DCE. The over‐all association constants of [Pb(ECCAT)3]2+ and [Cd(ECCAT)3]2+ complexes in DCE‐phase have been determined to be log β =14.03 and log β =15.44, respectively. 相似文献
103.
A review of heat treatment on polyacrylonitrile fiber 总被引:3,自引:0,他引:3
Developing carbon fiber from polyacrylonitrile (PAN) based fiber is generally subjected to three processes namely stabilization, carbonization, and graphitization under controlled conditions. The PAN fiber is first stretched and simultaneously oxidized in a temperature range of 200-300 °C. This treatment converts thermoplastic PAN to a non-plastic cyclic or a ladder compound. After oxidation, the fibers are carbonized at about 1000 °C in inert atmosphere which is usually nitrogen. Then, in order to improve the ordering and orientation of the crystallites in the direction of the fiber axis, the fiber must be heated at about 1500-3000 °C until the polymer contains 92-100%. High temperature process generally leads to higher modulus fibers which expel impurities in the chain as volatile by-products. During heating treatment, the fiber shrinks in diameter, builds the structure into a large structure and upgrades the strength by removing the initial nitrogen content of PAN precursor and the timing of nitrogen. With better-controlled condition, the strength of the fiber can achieve up to 400 GPa after this pyrolysis process. 相似文献
104.
E. Abdel-Latif H. M. Mustafa H. A. Etman A. A. Fadda 《Russian Journal of Organic Chemistry》2007,43(3):443-448
The reaction of malononitrile dimer with phenyl isothiocyanate gave (6-amino-1-phenyl-2-thioxo-1,2,3,4-tetrahydropyrimidin-4-ylidene)malononitrile
which was then used as starting material in the synthesis of pharmacologically important fused pyrimidine derivatives, such
as 4-dicyanomethylidene-1,5-diphenyl-2-thioxo-1,2,3,4-tetrahydropyrrolo[2,3-d]pyrimidine, 6-cyano-4-dicyanomethylidene-7-methylsulfanyl-5-oxo-1-phenyl-2-thioxo-1,2,3,4,5,8-hexahydropyrido[2,3-d]pyrimidine, 6-dicyanomethylidene-3-phenyl-2-thioxo-1,2,3,6-tetrahydro-9H-purine, and 6-substituted 4-dicyanomethylidene-7-oxo-1-phenyl-2-thioxo-1,2,3,4,7,8-hexahydropteridines.
Published in Russian in Zhurnal Organicheskoi Khimii, 2007, Vol. 43, No. 3, pp. 443–449.
The text was submitted by the authors in English. 相似文献
105.
The synthesis of a new bis(oxazoline) ligand from D-glucosamine and its application in enantioselective copper(I) catalysed cyclopropanations of olefins is described. 相似文献
106.
Abdurrahmanoğlu S Ozkaya AR Bulut M Bekaroğlu O 《Dalton transactions (Cambridge, England : 2003)》2004,(23):4022-4029
A new sandwich-tpype dilutetium tetraphthalocyanine 4 has been synthesized by the reaction of dimeric lutetium(III) phthalocyanine 3 with two equiv. of dilithium octakishexylthiophthalocyanine in amyl alcohol. Compound 3 was prepared from 4',5',4",5"-tetraiminoisoindoline(1,4,7,10-tetrathia-12-crown-4) 1, 4,5-bis(hexylthio)-1,2-diiminoisoindoline and lutetium acetate in amyl alcohol. Compounds 3 and 4 were characterized by elemental analysis, UV/visible, IR, (1)H NMR and ESR spectroscopy. The electrochemical and electrochromic properties of 3 and 4 have been examined by cyclic voltammetry. Both 3 and 4 displayed well-defined electrochromic behavior. 相似文献
107.
Bassam Abu Thaher Jalal A. Zahra Mustafa M. El-Abadelah Hans-Hartwig Otto 《Monatshefte für Chemie / Chemical Monthly》2004,40(9):435-439
Nitrilimines were prepared from N-arylhydrazono chlorides and reacted with -alanine yielding the corresponding amidrazones, which were treated with 1,1-carbonyldiimidazole in THF affording the hitherto unknown 3-acetyl-1-aryl-1,4,5,6-tetrahydro-1,2,4-triazepin-7-ones. 相似文献
108.
Eriksson J Malmsten M Tiberg F Callisen TH Damhus T Johansen KS 《Journal of colloid and interface science》2005,284(1):99-106
Enzymatic degradation of model cellulose films prepared by a spin-coating technique was investigated by ellipsometry. The cellulose films were prior to degradation characterized by ellipsometry, contact angle measurements, ESCA (electron spectroscopy for chemical analysis) and AFM (atomic force microscopy). At enzyme addition to preformed cellulose films an initial adsorption was observed, which was followed by a total interfacial mass decrease due to enzymatic degradation of the cellulose films. The degradation rate was found to be constant during an extended time of hours, whereafter the degradation leveled off. In parallel to the decreased interfacial mass, the cellulose degradation resulted in a thinner and more dilute interfacial film. At long degradation times, however, there was an expansion of the cellulose film. The enzyme concentration affected the degradation rate significantly, with a faster degradation at a higher enzyme concentration. The effects of pH, temperature, ionic strength and stirring rate in the cuvette were also investigated. 相似文献
109.
110.
Syed Mustafa Muhammad Waseem Abdul Naeem Khizar Hussain Shah Tauqeer Ahmad Muhammad Safdar 《中国化学》2010,28(11):2204-2208
The current study focuses on the synthesis and sorption properties of two mixed oxides of iron and silicon prepared by physical mixing (M1) and sequential precipitation methods (M2). Both the mixed oxides were synthesized from equimolar ratios of Fe(OH)3 and SiO2 and characterized for surface area, EDX, XRD and PZC. The surface area, micropore volume and average pore width of the oxide M1 were higher as compared to the oxide M2. However, potentiometric titrations revealed that mixed oxide synthesized by this method had a very high capacity towards Cd2+ ions as compared to the mixed oxide M1. Sorption of Cd2+ ions at pH 5 on mixed oxide, M2 was found to increase with temperature in the range 288 to 318 K. Langmuir equation was found applicable to the sorption data with R2>0.99. Entropy (ΔS?), enthalpy (ΔH?) and free energy changes (ΔG?) were calculated which revealed the process to be endothermic and spontaneous in nature. 相似文献