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The aggregation in aqueous solutions of alkylated 1,4-diazabicyclo[2.2.2]octanes of various hydrophobicity and their adsorption at the water-air interface were studied by tensiometry, conductometry, potentiometry, viscosimetry, and ESR spectroscopy. The parameters of adsorption, critical micelle concentrations, concentrations of free counterions (bromide ions), and degree of binding of the counterions with micelles were determined. The intensification of the micelle formation ability of the surfactants with an elongation of the alkyl fragment was shown. The effective radii of ensembles of the hexadecyl and octadecyl derivatives were determined by the dynamic light scattering method. A relationship between the concentration dependences of the size of micelles and their shape was established.  相似文献   

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The complexation of 1-hexadecyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide with Ni(II) nitrate in acetone is studied by means of spectrophotometry (the Job–Ostromisslensky technique and molar ratios). The formation of 3: 1 and 1: 1 ligand: metal complexes is established and confirmed by mathematical modeling. The stability constants of the complexes and the change in the Gibbs free energy are determined.  相似文献   

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The catalytic effect of micellar systems based on alkylated 1,4-diazabicyclo[2.2.2]octanes on the alkaline hydrolysis of butyl chloromethyl 4-nitrophenyl phosphonate is reported. The catalytic effect is due to the reactants concentrating in the micellar phase. It increases with an increase in the hydrophobicity of the surfactant. The bicyclic surfactant manifests the higher efficiency than its cyclic and noncyclic analogues. The micellization properties of alkylated 1,4-diazabicyclo[2.2.2]octanes in aqueous solutions have been investigated by the NMR method. An increase in the hydrophobicity of the surfactant decreases the critical micelle concentration and increases the hydrodynamic radius and aggregation numbers of the micelles.  相似文献   

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Novel organometallic surfactants were synthesized from monoquaternized 1,4-diazabicyclo[2.2.2]-octanes of varied hydrophobicity [Alk = C n H2n+1, n = 14, 18] and lanthanum nitrates. The spectral, micelleforming, and adsorption properties of the synthesized compounds were studied by IR, 1Н NMR and electronic spectroscopy, tensiometry, conductometry, and potentiometry. The critical micelle concentrations, counterionic micellar binding constants, and adsorption parameters at the water–air interface were determined and compared with the respective characteristics of the ligands and conventional amphiphiles.  相似文献   

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Russian Journal of Physical Chemistry A - The Krafft temperature (ТKr) of 1-alkyl-4-aza-1-azoniabicyclo[2.2.2]octane bromides (Alk = n-C n H2n + 1, n = 14, 16, 18) (D-n) and complexes of them...  相似文献   

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Potentiometry, fluorimetry, dynamic light scattering, and transmission electron microscopy were used to study the aggregation properties of the complexes 1-hexadecyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide with transition metal nitrates [Cu(II), Ni(II), Co(II), and La(III)]. The critical micelle concentrations, aggregation numbers, the degree of counterion binding to micelles, the size of aggregates, and electrokinetic potentials were determined. The complexes exhibited a high antimicrobial activity, and some of them proved to be more potent than the reference drugs.  相似文献   

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The organic reactions catalyzed by 1, 4-diazabicyclo [2.2.2] octane (DABCO) are reviewed. Most of the reactions start conveniently from available substrate and proceed under mild conditions. The reactions are environmentally friendly and the catalyst can be recycled in some cases. The perspectives on DABCO-catalyzed reactions are pointed out. __________ Translated from Chemistry online, 2007, 70(10): 759–765 [译自: 化学通报]  相似文献   

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This article describes an efficient and easy method for oxidation of sulfides 1 to their corresponding sulfoxides 2 with 1-butyl-4-aza-1-azoniabicyclo[2.2.2]octane dichromate (BAAOD) under nonaqueous conditions in high yields.  相似文献   

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Amphiphilic complexes of 1-hexadecyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide (D-16) with nitrates of transition metals (La3+, Cu2+, Ni2+, and Co2+) have been synthesized and characterized. Absorption spectrophotometry in the UV, visible, and IR regions, as well as 1Н NMR spectroscopy, have been employed to study their spectral properties in water and organic media. Adsorption properties and micelleforming and solubilizing abilities of the amphiphilic complexes have been investigated in aqueous solutions by the methods of tensiometry and conductometry, as well as by solubilization of a water-insoluble dye (Orange OT). The values of the critical micelle concentration, adsorption parameters at a water/air interface, and solubilization capacity S of complex micelles have been determined. It has been shown that the most pronounced decrease in the critical micelle concentration (as large as two to three times) and differences in the adsorption characteristics and the S values as compared with those of ligand D-16 are observed for complexes of copper and lanthanum. The S values for these complexes are 1.3?2.5 and 3?6.5 times higher than those for D-16 and cetyltrimethylammonium bromide, respectively.  相似文献   

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Russian Chemical Bulletin - The aggregation and adsorption properties of a new complex of 1-hexadecyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide with copper dibromide were studied by methods of...  相似文献   

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杨华  田瑞  李也 《化学通报》2007,70(10):759-765
综述了有机小分子催化剂1,4-二氮杂双环[2.2.2]辛烷(DABCO)在有机合成反应中的应用与发展。这种有机小分子催化的反应大多数条件温和、操作简单;相对过渡金属而言,对环境友好;在一定条件下,这种催化剂可以回收再利用。  相似文献   

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Cationic polymerization of bicyclo ortho ester, 1-phenyl-4-ethyl-2,6,7-trioxabicyclo[2.2.2]octane, was carried out with Lewis acids and cation sources to obtain the polyether containing ester group in the side chain. It was found that boron trifluoride etherate was the most active initiator in the Lewis acids. Magnesium perchlorate and triphenylcarbenium tetrafluoroborate, which have lower nucleophilic counter ions, initiated effectively the polymerization of bicyclo ortho ester.  相似文献   

17.
将4-(2-羟乙基)哌啶蒸汽在425 ℃下通过CNM-3型固体酸催化剂进行分子内脱水反应,一步合成了目的产物1-氮杂环[2.2.2]辛烷(奎宁环),4 h内25 g 4-(2-羟乙基)哌啶蒸汽单程收率可达76.8%,最高收率84.3%。 该方法原料易得,适合于奎宁环的工业化制备。  相似文献   

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Double intramolecular cyclization of N,N-bis(2-chloroethyl)-N-N-bis(2-cyanoethyl)ethylenediamine leads to 1,4-bis(2-cyanoethyl)-1,4-diazoniabicyclo[2.2.2]octane dichloride, which undergoes decyanoethylation to 1,4-diazabicyclo[2.2.2]octane when it is heated. The structures of the compounds were confirmed by their IR and PMR spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 548–550, April, 1978.  相似文献   

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Conclusions The reaction of tris(-hydraxy-,,-trichloroethyl)phosphine with phenylboric anhydride in the presence of pyridine gives pyridinium 1-phenyl-3.5.8-tris(trichloromethyl)-1-boronato-2,6,7-trioxa-4-phosphabicyclo [2.2.2]octane.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimieheskaya, No. 2, pp. 469–471, February, 1985.  相似文献   

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