a simple, novel, efficient and three-component procedure for the synthesis of pyrimido[4,5-d]pyrimidine-2,4-dione derivatives by the reaction of 6-amino-1,3-dimethyluracil, aldehyde and 2-benzylisothiourea hydrochloride promoted by ionic liquid 1-butyl-3-methylimidazolium bromide ([bmim]br) under solvent-free conditions is reported. the presented method is benefited from operational simplicity,...

Self-aggregation of 1-butyl-3-methylimidazolium bromide ([bmim]Br) in D(2)O has been investigated using NMR spectroscopy. The (1)H spin-lattice relaxation times (T(1)) of the [bmim](+) increased with the decrease of concentration in the range of 0.1-3.0 mol dm(-3) as expected, however, in contrast, the (1)H-T(1) decreased below 0.1 mol dm(-3). The estimated (13)C-activation energies indicated t...

In this study, eight different types of imidazolium-based ionic liquids (ILs) were applied as new solvents in the extraction of flavonoids from grape skin, and compared to the conventional organic solvent extraction that was not reported earlier. The structure of anions, cations and concentration of ILs significantly affected extraction yields. The highest mass fractions of proanthocyanidins an...

The volume change and sorption of CO2 of ionic liquids(ILs) were measured in a high pressure view cell under supercritical fluid condition. Imidazolium-based ILs such as 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]), 1-butyl-3-methyl-imidazolium tetrafluoroborate ([bmim][BF4]), and 1-octyl-3-methylimidazolium tetrafluoroborate ([omim][BF ]) were employed in this research. The ef...

Experimental measurements of density at different temperatures ranging from 293.15 to 313.15 K, the speed of sound and osmotic coefficients at 298.15 K for aqueous solution of 1-ethyl-3-methylimidazolium bromide ([Emim][Br]), and osmotic coefficients at 298.15 K for aqueous solutions of 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]) in the dilute concentration region are taken. The data are ...

The solubility of β-cyclodextrin (β-CD) in ionic liquids (ILs) and the activity coefficients at infinite dilution (γ13(∞)) of more than 20 solutes (alkanes, aromatic hydrocarbons, alcohols) were measured in four chosen ionic liquids, their mixtures with β-CD, and in the β-CD at high temperatures from 338 to 398 K using the inverse gas chromatography. The intermolecular interactions, inclusion c...

A simple, novel, efficient and three-component procedure for the synthesis of pyrimido[4,5-d]pyrimidine-2,4-dione derivatives by the reaction of 6-amino-1,3-dimethyluracil, aldehyde and 2-benzylisothiourea hydrochloride promoted by ionic liquid 1-butyl-3-methylimidazolium bromide ([BMIm]Br) under solvent-free conditions is reported. The presented method is benefited from operational simplicity,...

This work aims to investigate the corrosion inhibition of mild steel in 1 M HCl solution by 1-octyl-3-methylimidazolium hydrogen sulphate 1-butyl-3-methylimidazolium sulphate, and chloride, using electrochemical, weight loss, surface analysis methods as well full quantum-mechanical treatment. Polarization measurements prove that studied compounds are mixed-type inhibitors with a predominantly a...