A new distance scale of planetary nebulae

A new scale of distances to planetary nebulae is proposed. This scale is free of the common a priori assumptions about the evolution of the nebulae and exciting stars. The recently found regression relationship between radius and temperature of the central star is employed. As the initial data for distance finding, we use the radio flux density of the nebulae and the stellar magnitude of the nucleus, or one of these parameters and the central star temperature. The distances to 75 planetary nebulae have been calculated, and their linear dimensions and hydrogen atom concentrations have been determined. It is found that the ionized masses of the planetary nebulae range from 10^–3 M to 1.419M.Radiophysical Research Institute, Nizhny Novgorod. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 38, No. 6, pp. 522–542, June, 1995.     

Synthesis of alkylN-(α-amidomethyl)glycinates from glycine esters,aroylamides, and formaldehyde

A one-step synthesis of alkylN-(-amidomethyl)glycinates from glycine esters or their salts, formaldehyde, and aroylamides was developed. The effect of the structure of the amide component and the reaction conditions on the yields of the products was investigated.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1078–1080, June, 1994.     

Simple route to secondary amides of phosphorylacetic acids and their use for extraction and sorption of actinides from nitric acid solutions

An efficient method for the synthesis of secondary alkylamides of phosphorylacetic acids (APA) was proposed. The method involves amidation of ethyl phosphorylacetates with primary aliphatic amines. The scope of reaction was determined. Reactions with ethylenediamine and 1,4-diaminobutane yield the corresponding bisamides; in the case of 1,3-diaminopropane, N-(3-aminopropyl)diphenylphosphorylacetamide or N,N-propylenebis(diphenylphosphorylacetamide) was obtained, depending on the reaction conditions. The extraction of americium(III) complexes and the sorption of uranium(VI) by sorbents with physically sorbed APA from nitric acid solutions were studied. There is no correlation between the partition coefficient of americium(III) and the structure of APA; in the sorption of uranium(VI), the degree of extraction depends on the complexone structure.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2394–2402, November, 2004.     

Electroconductivity,Nature of Conduction,Thermodynamic Stability of the BaPr1 –xYxO3 – αCeramics

The electroconductivity and the nature of conduction of vacuum-dense ceramics BaPr_{1 – x} Y _x O_{3 –} (x= 0.05–0.15) is studied at temperatures of 373 to 985°C, of 2.1 × 10⁴to 10^–11Pa, and of 40 to 2400 Pa. The coefficient of linear thermal expansion is measured. The ceramics have a perovskite structure and are practically p-type semiconductors with a maximum conductivity of 0.26 S cm^–1at x= 0.10 and 800°C, in air. The share of ionic (proton) conductivity of the ceramics does not exceed 0.2–0.4%. The conductivity is weakly dependent on the air humidity. In a hydrogen-containing atmosphere, the ceramics undergoes reduction with destruction. Boundaries of thermodynamic stability of BaPr_0.9Y_0.1O_{3 –} at 500–900°C are determined.     

Chemical properties ofN-(amidomethyl)- andN-(imidomethyl)glycine derivatives

N-Nitroso,N-sulfonyl, andN-acyl derivatives ofN-(amidomethyl)- andN-(imidomethyl)-glycine esters have been synthesized by the reactions of these esters with HNO₂ or with sulfonylating and acylating reagents.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1299–1305, July, 1995.     

Extraction Properties of Oligodentate Carbamoylmethylphosphine Oxides and β-Aminophosphine Oxides Toward Lanthanides and Rhenium(VII)

Abstract

The extraction properties of a series of carbamoylmethylphosphine oxides and β-aminophosphine oxides with lanthanide metal ions is presented. Tris[bis(2-diphenyl- phosphorylethyl)-aminoethyl]amine is shown to be highly effective for extraction of Re(VII).     

Design of phosphonate analogs of short peptides by “click” chemistry

Methods were developed for the first time for the modification of the natural neuropeptides Ile–Gly–Leu and Leu–Gly–Leu simultaneously with the phosphonate moiety and the triazole ring or solely with the triazole ring by means of click chemistry. All of the peptidomimetics synthesized were isolated as a mixture of diastereomers and were characterized by spectroscopic methods.

     

Study of thermochemical properties of diphenyl[dialkyl(alkyl)carbamoylmethyl]phosphine oxides

The synthesis and the studies of properties of diphenyl[dialkyl(alkyl)carbamoylmethyl]phosphine oxides by differential scanning calorimetry, mass spectrometry and Knudsen effusion method were performed. The thermodynamic parameters of melting and vaporization were calculated.     

Alkaloids ofConvolvulus subhirsutus

The total alkaloids of the roots ofConvolvulus subhirsutus collected in the period of vigorous growth close to the village of Dzhilga, Chimkent province, have been studied. From the phenolic fraction of the total alkaloids of this species of plant we have isolated phyllalbine and convolidine for the first time. From the nonphenolic fraction of the combined bases we isolated convolvine, which has been found previously, the new alkaloid confoline, and an unidentified base (III). On the basis of spectral characteristics and some spectral transformations it has been established that confoline has the structure of (+)-N-formylconvolvine. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 672–676, September–October, 1980.     

Mono and bis[N-aryl(benzyl)]amides of phosphorylacetic acids. One-pot synthesis and extraction of actinides from nitric acid solutions

A one-pot synthetic route to phosphorylacetic acid N-aryl(alkylaryl)amides, including those containing two phosphorylmethylcarbamoyl moieties attached to the arene framework, has been developed. The method is based on reactions of amines with the corresponding acid chlorides generated in situ with the use of phosphorus trichloride as a mild chlorinating agent. The compositions and structures of the compounds obtained and their extraction ability toward Am^III were determined. Suggestions were made about the compositions of the extracted complexes with phosphorylacetic acid N-aryl(alkylaryl)amides. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1387–1394, August, 2006.