排序方式: 共有5条查询结果,搜索用时 31 毫秒
1
1.
Jigisha Parikh Jitendra Rathore Darshak Bhatt Meghal Desai 《Journal of Dispersion Science and Technology》2013,34(10):1392-1398
The present study investigates the effect of different additives on the cloud point (CP) of nonionic surfactants Triton X-100 (TX-100) and Triton X-114 (TX-114) in aqueous solutions. The thermodynamic parameters of these mixtures were calculated at different additive concentrations. The cloud point of nonionic surfactants TX-100 and TX-114 decreased with the increment of electrolyte concentrations and increased with alcohol concentrations. The standard Gibbs free energy was found to be positive for both the surfactants, whereas the enthalpy and the entropy of the clouding phenomenon were found to be positive with alcohols and negative with electrolytes. The overall clouding process was endothermic for alcohols and exothermic for electrolytes. 相似文献
2.
A facile method for the regioselective synthesis of tetrasubstituted pyrroles, from readily accessible 1,3-dicarbonyls, benzoin derivatives and ammonium acetate, has been developed. The one-pot three-component reactions were performed to afford tetrasubstituted pyrroles under solvent- and catalyst-free conditions. 相似文献
3.
[structure: see text] Long chain alkyl-alkyl interactions appears to be the main driving force in hydrogen bond isomerism induced transformation of lamellar architectures to nanotubular constructs in alkylammonium dicarboxylate salts; the syntheses of the nanotubes require no skill for typical organic synthesis, and they are functional materials displaying intriguing gelling properties. 相似文献
4.
Trivedi DR Ballabh A Dastidar P Ganguly B 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(21):5311-5322
Organic salts based on dicyclohexylamine and substituted/unsubstituted cinnamic acid exhibit efficient gelation of organic fluids, including selective gelation of oil from an oil/water mixture. Among the cinnamate salts, dicyclohexylammonium 4-chlorocinnamate (1), 3-chlorocinnamate (2), 4-bromocinnamate (3), 3-bromocinnamate (4), 4-methylcinnamate (5) and the parent cinnamate (6) are gelators, whereas 2-chlorocinnamate (7), 2-bromocinnamate (8), 3-methylcinnamate (9), 2-methylcinnamate (10) and hydrocinnamate (11) are non-gelators. Non-gelation behaviour of 11 and various benzoate derivatives 12-18 indicate the significance of an unsaturated backbone in the gelation behaviour of the cinnamate salts. A structure-property correlation based on the single-crystal structures of most of the gelators (1, 3, 5 and 6) and non-gelators, such as 7, 8, 10-18, indicates that the prerequisite for the one-dimensional (1D) growth of the gel fibrils is mainly governed by the 1D hydrogen-bonded network involving the ion pair. All the non-gelators show either two- (2D) or zero-dimensional (0D) hydrogen-bonded assemblies involving the ion pair. The molecular packing of the fibres in the xerogels of 1, 3, 5 and 6 has also been established on the basis of their simulated powder diffraction patterns, XRPD of bulk solids and xerogels. Ab initio quantum chemical calculations suggests that pi-pi interactions is not a contributing factor in the gelation process. 相似文献
5.
An Efficient Three‐component,One‐pot Synthesis of Quinazolines under Solvent‐free and Catalyst‐free Condition 下载免费PDF全文
Subrahmanya Ishwar Bhat U. K. Das Darshak R. Trivedi 《Journal of heterocyclic chemistry》2015,52(4):1253-1259
An efficient green protocol for the synthesis of quinazolines in the absence of solvent and catalyst has been developed. 2,4‐Disubstituted quinazolines have been synthesized from three‐component one‐pot reactions of 2‐aminoaryl ketones, orthoesters, and ammonium acetate. The present method has advantages of operational simplicity, substrate generality, clean reaction, high yields (76–94%), and moderate reaction time. The plausible mechanism of the reaction has been proposed based on the spectral characterization and single crystal X‐ray analysis of isolated intermediate. 相似文献
1