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91.
《Electroanalysis》2004,16(16):1359-1365
Electrochemical oxidation of catechols has been studied in the presence of cyanide ion as nucleophile in aqueous solution, by means of cyclic voltammetry and controlled‐potential coulometry. The results indicate that the participation of catechols in the Michael reaction with cyanide ion to form the corresponding o‐dihydroxybenzonitrile. Based on an EC mechanism, the homogeneous rate constants were estimated by comparing the experimental cyclic voltammetric responses with the digital simulated results. 相似文献
92.
93.
E. M. Afsah M. M. Abou-Elzahab M. T. Zimaity G. R. Proctor 《Monatshefte für Chemie / Chemical Monthly》1984,115(8-9):1065-1070
When -keto-ester1 a was reacted with dimethyl acetylenedicarboxylate ring expansion occurred to give substituted cyclooctadienones.Michael reactions of the title compounds1 with unsaturated ketones gave adducts, some of which underwent further cyclization reactions. A new route to -tetralone ring system10 via cyclization of the intermediateMichael adduct9 is described.
Michael- und Ringerweiterungsreaktionen von 6-Carboethoxy-3,5-diaryl-2-cyclohexen-1-onen
Zusammenfassung Bei der Reaktion von -Keto-ester1 a mit Dimethyl-acetylendicarboxylat wurden unter Ringerweiterung substituierte Cyclooctadienone erhalten. DieMichael-Reaktion der Titelverbindung1 mit ungesättigten Ketonen ergab Addukte, von denen einige weitere Cyclisierungsreaktionen eingingen. Es wird ein neuer Weg zum -Tetralonsystem10 über die Cyclisierung des intermediärenMichael-Addukts9 beschrieben.相似文献
94.
Ingrid M. M. Fussing Derek Pletcher Richard J. Whitby 《Journal of organometallic chemistry》1994,470(1-2):109-117
The syntheses of several new CpTiCl2(OR) (R = alkyl, aryl) complexes are described. It was possible to isolate pure product when the R group is substituted such as to cause steric crowding at the metal centre; for example, particularly good yields of the phenolate complexes were obtained when there were isopropyl substituents in the 2 and 6 positions of the phenolate. Electrochemical studies of the complexes in dry THF show that the TiIII complexes are relatively stable, but only a diol complex could be reduced further to a TiII species. In general, the TiIV complexes undergo a reversible 1e− reduction reaction. The chemistry is more complex if the electrolyte contains added water: both the TiIV and TiIII complexes can react with water, the OR group being replaced by OH. The reaction is particularly rapid for the TiIII alkoxide complexes. 相似文献
95.
Several new methyl-substituted indenyl ferrocenes were prepared by metathesis reactions of the indenide (generated from the appropriate indene with BuLi) with ferrous chloride. The indenides used to prepare new ferrocenes were: 2-methyl-, 1,2-dimethyl-, 4,7-dimethyl-, 1,4,7-trimethyl-, and 1,3,4,7-tetramethyl-indenide. These indenyl ferrocenes, along with those prepared from indenide, 1-methylindenide, and 1,3-dimethylindenide, were then characterized by 1H and 13C NMR, UV/visible spectroscopy, cyclic voltammetry and mass spectrometry. The cyclic voltammetry showed an additive relationship between oxidation potential and the number of methyl groups which is also position-dependent, whereas the UV/visible spectra showed two absorptions essentially unaffected by methyl substitution. Additionally, bis(2-methylindenyl)iron(II) and bis(4,7-dimethylindenyl)iron(II) were characterized by X-ray crystallography. 相似文献
96.
Rolf Meyer Zu Kcker Gerlinde Frenzen Bernhard Neumüller Kurt Dehnicke Jrg Magull 《无机化学与普通化学杂志》1994,620(3):431-437
Syntheses and Crystal Structures of the Phosphaneimine Complexes MCl2(Me3SiNPMe3)2 with M = Zn and Co, and CoCl2(HNPMe3)2 The molecular complexes MCl2(Me3SiNPMe3)2 (M = Zn, Co) have been prepared by the reaction of the dichlorides of zinc and cobalt with Me3SiNPMe3 in CH3CN and CH2Cl2, respectively, whereas the complex CoCl2(HNPMe3)2 has been prepared by the reaction of CoCl2 with NaF in boiling acetonitrile in the presence of Me3SiNPMe3. All complexes were characterized by IR spectroscopy and by crystal structure determinations. The complexes MCl2(Me3SiNPMe3)2 crystallize isotypically. ZnCl2(Me3SiNPMe3)2: Space group P212121, Z = 4, 2677 observed unique reflections, R = 0.024. Lattice dimensions at ?70°C: a = 1243.6; b = 1319.0; c = 1464.7 pm. CoCl2(Me3SiNPMe3)2: Space group P212121, Z = 4, 3963 observed unique reflections, R = 0,071. Lattice dimensions at ?80°C: a = 1236.3; b = 1317.4; c = 1457.6 pm. CoCl2(HNPMe3)2 · CH2Cl2: Space group Pbca, Z = 8, 1354 observed unique reflections, R = 0.055. Lattice dimensions at ?80°C: a = 1247.3; b = 998.4; c = 2882.4 pm. All complexes have monomeric molecular structures, in which the metal atoms are coordinated in a distorted tetrahedral fashion by the two chlorine atoms and by the nitrogen atoms of the phosphaneimine molecules. 相似文献
97.
两组份互穿网络聚合物的合成研究 总被引:1,自引:0,他引:1
以蓖麻油聚氨酯和聚醚聚氨酯的不同重量比与光敏剂、催化剂、稀释剂、促进剂所组成的多相体系为反应物,分别在紫外光照射和加热的条件下合成网络Ⅰ和网络Ⅱ的互穿网络聚合物(IPN)。改变网络Ⅱ聚醚聚氨酯中各组份的摩尔比制得系列样品。红外光谱,应力-应变曲线和动态力学性能测定发现,样品的力学性能与两组份重量比和网络Ⅱ中不同组成都存在着一定关系。这些结果,为该体系IPN的合成和应用提供了一定依据。 相似文献
98.
This review is a concise survey about the works in our laboratory on the polymerization of aromatic and heterocyclic dinitriles, including the polymerization kinetics and mechanism, synthesis of heterocyclic dinitriles, the structure of polymers, and the correlation between the structures of dinitriles and polymerization rates and thermal performances of Polymers. 相似文献
99.
WANG Shou-Wu YANG Yuan LI Bao-Long ZHANG Yong 《结构化学》2007,26(7):763-766
The new cadmium(II) coordination polymer [Cd(bte)2(dca)2]n 1 (bte = 1,2-bis(1,2,4- triazol-1-yl)ethane, dca = dicyanamide) was synthesized and characterized by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/n with a = 8.7148(15), b = 8.6142(17), c = 15.204(3) A, β = 92.100(10)o, V = 1140.6(4) A3, Z = 2, Mr = 572.87, Dc = 1.668 g/cm3, F(000) = 572, μ = 1.004 mm-1, the final R = 0.0654 and wR = 0.1429 for 1737 observed reflections (I > 2σ(I)). The cadmium atom is coordinated equatorially by four nitrogen atoms from four bte ligands and axially by two nitrogen atoms from two dca anions to adopt a distorted octahedral geometry. Each bte molecule bridges two cadmium(II) atoms. Two strands of bte molecules are wrapped around each other, and held together by cadmium(II) atoms. 1 Forms a double chain structure containing eighteen-membered Cd2(bte)2 rings. 相似文献
100.
本文主要叙述了以国产717强碱性阴离子交换树脂为基体,采用甲醛与对苯二酚、邻苯二酚、连苯三酚和2,7-萘二酚等聚合生成氧化还原树脂,它们的氧化还原容量分别为5.3,5.4和5.2meq/g-干树脂.文中还介绍了本类树脂的氧化还原电位测定方法,并据此研究和测定了对苯二酚、邻苯二酚和连苯三酚型树脂的氧化还原电位,这些电位的测定结果与其氧化还原实验事实相符.也研究了多种氧化剂和还原剂与自制树脂的交换性能,讨论了这些树脂容量与交换性能的关系.应用所合成的新树脂进行了从硝酸银废液中回收银和对硫化氢试行氧化脱硫处理试验,效果良好. 相似文献