Micellar Extraction of Carboxylic Acids with Phases of OP-10 Nonionic Surfactant on Heating

Extraction of carboxylic acids from aqueous solutions with phases of OP-10 nonionic surfactant on heating was studied in relation to the concentration and hydrophobicity of the acids. A multiple linear regression equation describing the process was suggested.     

Micellar extraction preconcentration of silver with thiazolylazo reagents into a nonionic surfactant phase at the cloud point

The effect of the main factors on the extraction of the silver complexes of 4-(2-thiazolylazo)resorcinol and 1-(2-thiazolylazo)-2-naphthol into a micellar phase of a nonionic surfactant at the cloud point was studied. Conditions were found for the atomic absorption determination of silver with micellar extraction preconcentration into an OP-7 phase upon heating.     

Synthesis,structural characterization and anticancer properties of p-cymene Ru(II) complexes with 2-(N-methyl-1H-1,2,4-triazol-3-yl)pyridines

Transition Metal Chemistry - The structures of new p-cymene Ru(II) complexes with 2-(1-methyl-1H-1,2,4-triazol-3-yl)pyridine and 2-(1-methyl-1H-1,2,4-triazol-5-yl)pyridine were established based on...     

Atomic-Absorption Determination of Zinc in Water with Micellar-Extraction Preconcentration with Phases of Nonionic Surfactants

Effects of various factors on the extraction of zinc with carboxylic acids and their mixtures with amines into a micellar phase of a nonionic surfactant at the cloud point were studied. The conditions for the atomic-absorption determination of zinc preconcentrated into an OP-10 phase on heating with capric acid and n-octylamine were developed.     

Preconcentration of Cadmium with OP-10 Nonionic Surfactant Phases at the Cloud Point

The effect of the main parameters on the extraction of cadmium with carboxylic acids into the micellar phase of the OP-10 nonionic surfactant at the cloud point was studied. Conditions were found for the atomic absorption determination of cadmium in natural and waste waters using the micellar-extraction preconcentration with capric acid and n-octylamine into the surfactant phase.__________Translated from Zhurnal Analiticheskoi Khimii, Vol. 60, No. 5, 2005, pp. 458–462.Original Russian Text Copyright © 2005 by Doroshchuk, Kulichenko.     

Micellar phases based on sodium dodecyl sulfate for preconcentration

Features of phase formation from solutions of sodium dodecyl sulfate on cooling were examined. The effect of electrolyte and phenol additions on the parameters of phase formation and distribution of model substrates was examined. Conditions were found for albumin preconcentration with phases in the system sodium dodecyl sulfate-phenol-NaCl.     

Cascade reactions for constructing heterocycles containing a pyrimidino-pyrazino-pyrimidine core using 1,2,4-triazole scaffolds

The regioselective cyclocondensation of aminoethyl-1,2,4-triazoles and glyoxal provides pentacyclic heterocycles in which two 7,8-dihydro-5H-6λ²-[1,2,4]triazolo[1,5-c]pyrimidine systems are connected through CH(OH) bridges generating a central piperazine-2,5-diol ring. The structure of the new compounds was elucidated based on ¹H, ¹³C and ¹⁵N NMR spectroscopic methods. The molecular structure of the parent compound generated from aminoethyl-1,2,4-triazole was established by single crystal X-ray diffraction.     

An alternative approach to the synthesis of [1,2,4]triazolo[1,5-a]pyridine-8-carbonitriles,their crystal structure,and DFT calculations

New representatives of [1,2,4]triazolo[1,5-a]pyridine-8-carbonitriles were synthesized via the condensation of β-diketones or β-dialdehydes and characterized using MS spectrometry, ¹H, ¹³C and, ¹⁹F NMR and IR spectroscopy. Crystal structures of two compounds were established using X-ray analysis and showed that title compounds are prone to the formation of planar molecules. The absence of band responsible for CN stretching vibration in trifluoromethyl-containing compounds was explained using the DFT calculations method, which also showed a significant influence of fluorines introducing on the energy gap between HOMO and LUMO.