Extraction of lanthanides(III) by phosphorylated naphthyridine ligands from carbonate solutions

The extraction capacities and selectivities of 1,8-naphthyridine-based neutral organophosphorus reagents in extracting trivalent lanthanides (Ln, Nd, Ho, Yb) from carbonate solutions were studied. The length and nature of the linker between the naphthyridine and phosphoryl moieties were found to have considerable influence on the efficiency and selectivity of lanthanide extraction.     

Density and viscosity of methanol-heptane (octane) mixtures at low alkane concentrations over the temperature range 288.15–328.15 K

An Anton Paar 4500 densimeter was used to measure the density of methanol-heptane and methanol-octane solutions in the region of low alkane concentrations over the temperature range 288.15–328.15 K. The experimental data were used to calculate the apparent, partial, and excess molar volumes of alkanes. Viscosity was measured with an Ubbelohde viscometer at 298.15 K. The NMR spectra were recorded on a Bruker Avance III BioSpin spectrometer. The physicochemical characteristics of methanol-heptane and methanol-octane mixtures were considered in combination with molecular dynamics simulation results. The conclusion was drawn that methanol was structured in mixtures with heptane at concentrations of 0.04–0.06 alkane mole fractions. This peculiarity was not observed in mixtures with other alkanes.     

Intermolecular direct arylation of five-membered ring heterocycles by non-activated aryl chlorides

The use of non-activated aryl chloride electrophiles in the direct arylation of carbon–hydrogen bonds in five-membered ring heterocycles is described. Specifically, palladium-, ruthenium-, and nickel-catalyzed transformations, as well as reactions proceeding via benzyne intermediates, are discussed.     

Formation of the fused system 5H,7H-pyrido[2,3-b:6,5-b′]diindole from 3-arylidene-2-ethoxyindolenines and hydrazine hydrate

Three 12-aryl-5H,7H-pyrido[2,3-b:6,5-b??]diindoles (Ar = Ph, 4-BrC₆H₄, and 4-MeOC₆H₄) were obtained from appropriate 3-arylidene-2-ethoxyindolenines and hydrazine hydrate.     

Use of galvanostatic coulometry in the analysis of arbidol drug

Arbidol is proved to easily and completely react with electrogenerated bromine in the ratio 2: 9; so procedures for the arbidol quantification in the neat substance and drugs are developed, the RSD value does not exceed 2%. A procedure for the coulometric determination of water in the arbidol substance using the Fisher method is proposed.