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A vinyl bis-sulfone Michael type approach towards heteroatom vinylation was applied on nitrogen derivatives. Cyclic thionocarbamates--mainly 1,3-oxazolidine-2-thiones--were converted into their N-vinyl counterparts; the procedure proved particularly efficient in the case of carbohydrate-derived complex structures. 相似文献
3.
FitzGerald PA Carr MW Davey TW Serelis AK Such CH Warr GG 《Journal of colloid and interface science》2004,275(2):649-658
Dimeric poly(ethylene oxide) surfactants (or nonionic gemini surfactants) with the structure (Cn-2H2n-3CHCH2O(CH2CH2O)mH)2(CH2)6 (or GemnEm), where n is the alkyl length and m is the average number of ethylene oxides per head group, were synthesized. Surfactants were synthesized with alkyl chain lengths n = 12, 14, and 20 and m = 5, 10, 15, 20, and 30. Water solubilities and cloud temperatures at 1 wt% were determined by measuring turbidity as a function of temperature. Cloud temperatures increase with m and decrease with n, as observed for conventional surfactants. For large m the cloud temperatures were all above 100 degrees C. Surfactants with small m (i.e., n = 12, 14, m = 5 and n = 20, m = 10) were insoluble at room temperature, forming two-phase mixtures. Critical micelle concentrations (CMCs) were measured using a pyrene fluorescence method and are all in the range of 10(-7) to 10(-6) M, with the lowest values from the surfactants with large n and small m. CMCs of mixtures with both anionic and nonionic conventional (monomeric) surfactants were well described by an ideal mixing model. 相似文献
4.
Sigitas Tumkevicius Linas LabanauskasVirginija Bucinskaite Algirdas BrukstusGintaras Urbelis 《Tetrahedron letters》2003,44(35):6635-6638
(1-Amino-1H-benzimidazol-2-yl)methanol 1 with thionyl chloride at reflux afforded 3-chlorobenzimidazo[1,2-c][1,2,3]thiadiazole 4, which reacted with various nucleophiles to give different products depending on the nature of the solvent. The structures of 4 and di(benzimidazo[1,2-c][1,2,3]thiadiazol-3-yl)sulfide 8 were confirmed by single-crystal X-ray analysis. 相似文献
5.
Neringa Kleizien? Virgin? Amankavi?ien? Ulf Berg Carsten Schicktanz Klaus Schlothauer Algirdas ?a?kus 《Monatshefte für Chemie / Chemical Monthly》2006,43(9):1109-1117
Condensation of 1-substituted 1,2,3,9a-tetrahydro-9H-imidazo[1,2-a]indol-2-ones with 5-nitrosalicylaldehyde afforded 1′-[(N-monosubstituted carbamoyl)methyl]indoline nitrospirobenzopyrans.
Treatment of the latter with strong base led to the formation of a mixture of cis/trans-5a,13-methano-1,3-benzoxazepino[3,2-a]indoles. Results of semiempirical calculations gave evidence that such a transformation of nitrospirobenzopyrans to bicyclic
indole derivatives could proceed via a single transition state, where the negatively charged carbon atom attacks the vinylic double bond of the spiropyran system. 相似文献
6.
Heating of 1′‐(N‐substituted carbamoyl)methylspiro[2H‐1‐benzopyran‐2,2′‐[2H]indoles] with potassium hydroxide in ethanol yields diastereomeric 5a,13‐methano‐6H‐1,3‐benzoxazepino[3,2‐a]indole‐12‐carbox‐amides. Reduction of the latter with sodium borohydride affords 1,2,3,9a‐tetrahydro‐2‐hydroxyaryl‐9H‐pyrrolo[ 1,2‐a] indole‐3 ‐carboxamides. 相似文献
7.
Algirdas Matijoška Tatjana Charkova Zenonas Kuodis Vladislava Voiciuk Olegas Eicher-Lorka 《Central European Journal of Chemistry》2012,10(1):113-120
The synthesis of a new halogenide containing hexyltriethylene glycol chain functionalized with biotin is reported. The general
possibility of this linker to use as the building block for biotinylated compounds syntheses is demonstrated. Two biotinylated
esters with different properties for useful surface modification and as fluorescence probes for proteins marking were synthesized.
The properties of mentioned compounds were investigated by using surface plazmon resonance ellypsometry and fluorescence spectroscopy. 相似文献
8.
9.
Arūnas Jagminas Marija Kurtinaitienė Kęstutis Mažeika Ričardas Rotomskis Gediminas Niaura Algirdas Selskis 《Journal of nanoparticle research》2011,13(9):4133-4142
Developing of a simple method for the fabrication of superparamagnetic iron oxide nanoparticles (Nps) is still a challenge for materials scientists. This work reveals a way to fabricate especially stable ferrofluids from spherical Nps of magnetite using the co-precipitation method, for which a new (diglycolic acid) stabilizer was applied. The Nps of the average size of ~7.4–16.5 nm were characterized by means of high resolution transmission electron microscopy (HRTEM), atomic force microscopy (AFM), selective area electron diffraction (SAED), Raman, FTIR and Mössbauer spectroscopy. The stabilization effect of the diglycolic acid for the growth of superparamagnetic Nps growth was discussed on the basis of experimental results. 相似文献
10.
Genovaitė Valiulienė Albina Žielienė Birutė Šimkūnaitė Leonas Naruškevičius Loreta Tamašauskaitė Tamašiūnaitė Vidas Pakštas Algis Selskis 《Journal of Solid State Electrochemistry》2010,14(2):203-212
The electrochemical behavior of Bi2S3 coatings in Watts nickel plating electrolyte was investigated using the cyclic voltammetry, electrochemical quartz crystal
microbalance, X-ray diffraction, and energy dispersive X-ray analysis methods. During the bismuth sulfide coating reduction
in Watts background electrolyte in the potential region from −0.4 to −0.6 V, the Bi2S3 and Bi(III) oxygen compounds are reduced to metallic Bi, and the decrease in coating mass is related to the transfer of S2− ions from the electrode surface. When the bismuth sulfide coating is reduced in Watts nickel plating electrolyte, the observed
increase in coating mass in the potential region −0.1 to −0.4 V is conditioned by Ni2+ ions reduction before the bulk deposition of Ni, initiated by Bi2S3. In this potential region, the reduction of Bi(III) oxygen compounds can occur. After the treatment of as-deposited bismuth
sulfide coating in nickel plating electrolyte at E = −0.3 V, the sheet resistance of the layer decreases from 1013 to 500–700 Ω cm. A metal-rich mixed sulfide Ni3Bi2S2–parkerite is obtained when as-deposited bismuth sulfide coating is treated in Watts nickel plating electrolyte at a potential
close to the equilibrium potential of the Ni/Ni2+ system and then annealed at temperatures higher than 120 °C. 相似文献