Flame AAS determination of thallium in soils

The anion-exchange enrichment of TlCl(-)(4) coupled to flame AAS is applied to the determination of the total, pseudo-total (not bound in the silicate matrix) and mobile (plant available) content of thallium in soils. Ascorbic acid is used as a new efficient eluent of thallium. The limit of detection of the method is 0.04,mug/g, the relative standard deviation at the 1 mug/g level is about 3%. The method is rapid and simple.     

Interaction of Hydroxylamine with Esters of 2-Oxobutenoic Acids. Synthesis of 1-Hydroxy-3-hydroximino-2-pyrrolidinones

New 3-hydroximino-1-hydroxy-2-pyrrolidinones have been synthesized by the interaction of NH₂OH and NH₂OBn with the methyl esters of 2-oxo-3-butenoic acid derivatives. Some intermediate compounds have been isolated and identified and the reaction mechanism is discussed.     

Extractive substances of the bark of Picea ajanensis

A study of the chemical composition of a petroleum ether extract of the bark of Yeddo spruce growing in Khabarovsk Territory has shown that the neutral fraction of the extract contained waxes, glycerides, diterpenoids — epimanool, cis- and trans-abienols, and phyllocladenol, and triterpenoids — the epimeric 3α-and 3β-methoxy-21-hydroxy-Δ¹⁴-serratenes and a ketone which has been ascribed the structure of 21-keto-3β-methoxy-Δ¹⁴-serratene.     

Structure of Tetranuclear Iron(III) d- and dl-Tartrates in Aqueous Solutions

The geometric parameters of dl- and d-tetranuclear iron(III) tartrates [Fe₄(d-L)₂(l-L)₂(H₂O)₈]^4–and [Fe₄(d-L)₄(H₂O)₈]^4–(H₄L is tartaric acid) were optimized using the molecular mechanics method (MIND program, Dashevskii–Plyamovatyi model).     

Synthesis and immobilization of quaternary ammonium cations in acidic zeolites

A general method for the synthesis of quaternary ammonium cations in acidic zeolites by a direct reaction of tertiary amines and alcohols is described.     

Physico-chemical properties of iron-tin mixed oxide catalysts in cyclohexane oxidation

The state of mixed iron-tin oxide catalysts with a variable ratio of their metallic components has been studied by Mössbauer and ESCA spectroscopy. The results are compared with the activity of these catalysts in cyclohexane oxidation.

---

- . .

     

Programming package “ESCAPAK” for calculations of electronic structure,adapted for the ES series computers

Branch of the Institute of Chemical Physics, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 30, No. 3, pp. 132–134, May–June, 1989.     

Synthesis of methyl α-nitrocrotonate

Summary Methyl -nitrocrotonate has been synthesized by the condensation of methyl nitroacetate with acetaldehyde, acetylation of the methyl -nitro--hydroxybutyrate, and subsequent deacetylation of the resulting product.     

Electron paramagnetic resonance of carbon adsorbents from phenol-formaldehyde oligomers and their ability to adsorb noble metals

In order to establish the interrelation between the electronic characteristics of carbons that are manifested in the EPR spectra and their ability to adsorb complex gold and silver ions, the EPR spectra of carbon adsorbents from phenol-formaldehyde resins of various nature, unactivated and activated under various conditions, and the adsorption of [Au(CN)₂]^– and [Ag(CN)₂]^– from cyanide solutions on these same adsorbents were investigated. A parallel relation was observed between the amount of paramagnetic centers on carbon and its adsorption capacity and selectivity in relation to these anions.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 26, No. 6, pp. 742–745, November–December, 1990.