V. I. Karmanov

Extraction and complexing of copper(II) with benzoic acid N,N-dihexylhydrazide

The solubility and acid-base properties of benzoic acid N,N-dihexylhydrazide (BDHH) were studied. The extraction of copper(II), cobalt(II), nickel(II), zinc(II), iron(III), platinum(II), platinum(IV), chromium(III), chromium(VI), palladium(II), and molybdenum(VI) with this reagent was studied. It was shown that BDHH most efficiently extracts copper(II) from ammonia solutions and chromium(VI) from sulfuric acid solutions. In the extraction of copper(II), complexes with the [Cu(II)]: [BDHH] = 1: 1 and 1: 2 stoichiometries were found to form. The structure of the 1: 2 complex was suggested proceeding from its IR spectra. A copper(II) extraction isotherm was plotted.

Rhenium(VII) extraction with 2-ethylhexanoic acid N,N-dialkylhydrazides from acidic solutions

Rhenium(VII) extraction with 2-ethylhexanoic acid N′,N′-dialkylhydrazides in kerosene from acidic media was studied. Optimal extraction conditions were established depending on H2SO4, HCl and extractant concentrations and the composition of extracted complexes. A mechanism of perrhenate ion extraction and back-extraction with ammonium solutions was proposed.

Spirocyclohexadienones: X. Three-component condesation of 1,2,3- and 1,2,4-trimethoxybenzenes with cyclohexanecarbaldehyde and nitriles. Synthesis of 1,2- and 1,4-dimethoxy-14-azadispiro[5.1.5.2]pentadeca-1,4-dien-3-ones

Substituted 1,2- and 1,4-dimethoxy-14-azadispiro[5.1.5.2]pentadeca-1,4-dien-3-ones and 1,2(1,4)-dimethoxy-14-azadispiro[5.1.5.2]pentadeca-1,4,14-trien-3-ones were synthesized by three-component condensation of cyclohexanecarbaldehyde with 1,2,3- or 1,2,4-trimethoxybenzene and the corresponding nitriles in the presence of concentrated sulfuric acid.

Physical and chemical properties of N′,N′-aliphatic acid dioctylhydrazides and their complexing with copper(II) ions

Some physical and chemical properties of aliphatic acid N′N′-dioctylhydrazides[RC(O)NHN(C8H17)2] (DOHs) were studied in comparison to 2-ethylhexanoic acid N′N′-dialkylhydrazides, namely, solubility, acid-base properties, entrainment with an aqueous phase, and partition factors depending on the medium and the acyl radical length. The pH ranges of maximal extraction of copper(II) complexes by DOHs to kerosene and the effect of ammonium salts on copper(II) extraction were determined. The compositions of extracted complexes were determined (Cu(II): DOH = 1: 1 and 1: 2); the extraction constant Kextr was calculated for the CuL2 complex with butyric acid N′N′-dioctylhydrazide.

Alkylhydrazides and their protonated forms: Physical methods andab initio calculations

The basicity of hydrazides of the highest aliphatic carboxylic acids RC(O)NHNH2 (R = CnH2n+1,n = 5-12) has been studied by potentiometric titration, and IR and1H NMR spectroscopy.Ab initio Hartree-Fork calculations using the 6–31G* basis set with full optimization of geometry were carried out on the simplest acy1hydrazines and their possible protonated forms. Based on these calculations, and the 1R and1H NMR spectra, the tautomerism of alkylhydrazides and the structures of their protonated forms are discussed.

N-Heterocyclic Carbenes: VII.* Abietane-Based Adamantylimidazolium Salts

Adamantyl-substituted imidazolium salts were synthesized on the basis of abietane derivatives. The products were tested as N-heterocyclic carbene ligands in the palladium-catalyzed Sonogashira reaction.

Reaction of 2-substituted 7,7-dimethyl-5-oxo-5,6,7,8-tetrahydroquinoline-4-carboxylic acids with hydrazine. Synthesis of 5-substituted 8,8-dimethyl-3,7,8,9-tetrahydro-2H-pyrido-[4,3,2-de]cinnolin-3-ones

The reaction of 2-substituted 7,7-dimethyl-5-oxo-5,6,7,8-tetrahydroquinoline-4-carboxylic acids with hydrazine was studied. This reaction gave 5-substituted 8,8-dimethyl-3,7,8,9-tetrahydro-2H-pyrido-[4,3,2-de]cinnolin-3-ones in good yields. A possible reaction mechanism was discussed using nonempirical quantum-chemical calculations.

Extraction of vanadium(V) by N′,N′-dialkylhydrazides of carboxylic acids from acidic solutions

Extraction of vanadium(V) with solutions of 2-ethylhexanoic acid N′,N′-dialkylhydrazides in kerosene from acidic media was studied. The optimal extraction conditions were determined depending on the concentrations of H2SO2, HCl, and the extraction agent; the composition of the recovered complexes was proposed. The conditions for back-extraction of vanadium(V) from the organic phase were studied. It was found that benzoic acid N′,N′-diheptylhydrazide did not recover vanadium(V) from acidic media.

Copper(II) complexing with 2′,2′-diethylheptanohydrazide

Acid-base properties of 2′,2′-diethylheptanohydrazide (DEHH) and its complex formation with copper(II) ions in water-isopropanol solutions were studied. Cationic complexes with [Cu2+] : [DEHH] ratios of 1 : 1 and 1 : 2 were found to be formed in weak acid media, and an uncharged complex with a [Cu2+] : [DEHH] ratio of 1 : 2 was found to be formed in a basic medium. log Kst values were determined. The data obtained were compared with the stability constants of copper(II) 2′,2′-diethylbenzohydrazide complexes.

Symmetrical and unsymmetrical bis-1,1'-(3,4-dihydroisoquinolines)

Abstract3,3,-Dialkyl-1-cyano-3,4-dihydroisoquinolines were prepared by Beckmann defragmentation of ethyl α-(3,3-dialkyl-3,4-dihydroisoquinol-1-yl)-α-hydroximinoacetates and they take part in a Ritter reaction to form substituted bis-1,1′-(3,4-dihydroisoquinolines).