Ketoimines of Cardenolides

3-Keto-derivatives of the cardenolides digitoxigenin and cardiogenin were prepared with subsequent conversion to new ketoimines (1–19, 24–44), the oxime (23), and for the first time to pure cardiogenin (14,16-dianhydrogitoxigenin, 20), its acetate (21), and cardiogenone (22). Their physicochemical properties were described.__________Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 42–45, January–February, 2005.     

The 13C NMR spectra and structure of ferrocenylcarbenium ions

The ¹³C NMR spectra ofthe series of α,α’ -dideuterated ferrocenylcarbenium ions and their precursors, ferrocenylcarbinols as well as other ferrocene derivatives have been measured. The structures of ferrocenylcarbenium ions is discussed.     

Extraction of Aromatic Sulfonic Acids in the Presence of a Surfactant

Extraction of phenol- and naphtholsulfonic acids from aqueous salt solutions in the presence of a surfactant, N-cetylpyridinium chloride, with hexane, ethylbenzene, and acetone-diacetone alcohol is studied.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 1, 2005, pp. 79–82.Original Russian Text Copyright © 2005 by Korenman, Gubin, Sukhanov.     

Catalytic conversions of chloroolefins over iron oxide nanoparticles 2. Isomerization of dichlorobutenes over iron oxide nanoparticles stabilized on the surface of ultradispersed poly(tetrafluoroethylene)

Nanosized iron oxides stabilized on the surface of ultradispersed poly(tetrafluoroethylene) (UPTFE) granules were synthesized by the thermal destruction of iron formate in boiling bed of UPTFE on the surface of heated mineral oil. The particle size of nanoparticles (∼6 nm) containing 5, 10, and 16 wt.% Fe depends weakly on the temperature of synthesis and iron to polymer ratio. The metal state is determined by the synthesis conditions. The nanoparticles synthesized at 280 °C consist mainly of the Fe₃O₄ and Fe₂O₃ phases. The samples obtained at 320 °C also contain iron(II) oxide. The catalytic properties of the obtained samples were tested in dichlorobutene isomerization. Unlike isomerization on the iron oxide nanoparticles supported on silica gel, reaction over the UPTFE supports proceeds without an induction period. The sample with 10 wt.% Fe containing magnetically ordered γ-Fe₂O₃ nanoparticles possesses the highest catalytic activity. Fast electron exchange between the iron ions in different oxidation states and high defectiveness of the nanoparticles contribute, most likely, to the catalytic activity. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1383–1390, June, 2005.     

Ordered structures based on self-organized Au and CdSe nanoparticles

Methods for obtaining cadmium selenide and gold nanoparticles have been developed. The sizes of the nanoparticles are determined and the morphology, structure, and chemical composition of these nanoparticles and their ensembles are studied by a complex of structural methods: electron diffraction, X-ray diffraction, energy-dispersive X-ray analysis, high-resolution transmission electron microscopy, and small-angle X-ray scattering. Gold nanoparticles are mainly spherical and have an average size of 10 nm. They are single-phase and have an fcc crystal structure. Samples of synthesized CdSe nanoparticles contain monodisperse spherical particles 12 nm in size with a wurtzite structure. The deposition of nanoparticles on a carbon substrate is accompanied by their self-organization into a closely packed two-dimensional structure with a pronounced texture in which all nanoparticles are oriented in the [001] direction perpendicularly to the carbon substrate plane.     

Sorption of carbaryl and naphthols by polymers based on N-vinylamides from aqueous solutions

New cross-linked copolymers based on N-vinylpyrrolidone and N-vinylcaprolactam were proposed for preconcentration of carbaryl and naphthols from aqueous media. The influence of pH, nature of salting-out agent, surfactant, and temperature on the recovery of the analytes was examined. The most efficient sorption systems for recovery of carbaryl and naphthols from aqueous solutions were developed.     

Zinc oxide nanoparticles immobilized on graphene flake

Interactions of ZnO nanoparticles with graphene oxide in isopropanol were studied; graphene oxide was shown to perform as an efficient substrate to immobilize zinc oxide nanoparticles on its surface. Interactions of nanocomposites consisting of graphene oxide-zinc oxide nanoparticles with supercritical isopropanol were studied. The conversion of graphene oxide into graphene does not appreciably changes the composition, morphology, or structure of ZnO nanoparticles.