Fast and continuous chemical isolation of short-lived isotopes of Hf,Ta and W as homologs of elements 104, 105 and 106

Some short-lived isotopes of Hf, Ta and W, synthesized at the U-400 cyclotron of JINR-Dubna, have been isolated using a previously elaborated fast continuous method of chemical isolation of element 104 from nuclear reaction products. The products were transported by a NaCl aerosol jet, from the irradiated targets to a separation device in which Hf, Ta and W were isolated by using three coupled ion-exchange columns.     

Influence of the crystallinity of pentasil-type zeolites on their acidity

The acid properties of intermediate products in crystallization of pentasil-type zeolites have been investigated using programmed thermal desorption of ammonia and adsorption of pyridine. It was found that acidity increases with increasing crystallinity due to proton-donor centers. A correlation was established between this change in acidity and methanol TPSR data.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 31, No. 1, pp. 48–51, January–February, 1995.     

(α-Nitroalkyl)-ONN-azoxysulfones and some of their transformations

A regioselective method for the synthesis of [(-nitroalkyl)-ONN-azoxy]alkyl- and-arylsulfones by oxidative condensation of pseudonitroles with aliphatic and aromatic sulfamides under the action of dibromoisocyanurate (DBI) was proposed. The behavior of the azoxysulfones obtained toward acids and bases as well as futher transformations of the products of acid hydrolysis into salts and halo-derivatives of nitroalkylazoxysulfones were investigated.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1267–1270, July, 1994.     

Electrochemically induced formation of organomercury compounds

A procedure for the alkylation of metallic mercury by (dimethylglyoximato)butylcobalt(III) electrochemically generated in the presence of butyl bromide is proposed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 309–312, February, 1994.     

Triterpene glycosides ofHedera colchica. Structure of hederacolchisides E and F

The leaves of Colchis ivy (family Araliaceae) have yielded polar glycosides — hederacolchisides E and F — and their structures have been established. It has been shown on the basis of the results of methylation and of acid and alkaline hydrolysis that these glycosides are hexaosides of oleanolic acid and of hederagenin.     

Stereochemistry of 2-substituted 5,6-benzo-1,3,2-dioxarsepines

Russian Chemical Bulletin -     

Reaction of dihydroxymethylphenylphosphine with o-phenylenediamine

Conclusions The reaction of o-phenylenediamine with either one or two moles of dihydroxymethylphenylphosphine gives respectively either 3-phenyl-6,7-benzo-1,5-diaza-3-phosphepane or 9,10-benzo-3,7-diphenyl-1,5-diaza-3,7-diphosphabicyclo[3.3.2]decane.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 440–443, February, 1982.