IR spectroscopic study of substituent effects in N,N-dimethylhydrazides of aromatic acids

Conclusions An IR spectroscopic study showed that the C=0 values in the spectra of N,N-dimethylhydrazides of aromatic acids, RCONHN(Me)₂, correlate linearly with a regression equation obtained for the unsubstituted hydrazides of aromatic acids, RCONHNH₂. This dependence differs significantly from that for N-methyl-N-aroylhydrazines, in which ,-conjugation in the RC(O)N group is more pronounced.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2353–2355, October, 1987.     

Greffage radiochimique de l'acrylonitrile dans la masse de films de PTFE

Acrylonitrole can be grafted in the bulk of PTFE films provided the monomer is allowed to diffuse into the grafted zones. For a given radiation dose, the amount of grafting is higher the lower the dose-rate. Even higher grafting efficiencies are reached under conditions of discontinuous irradiations, the reacting mixture being stored in the dark in a thermostat between successive irradiations. The grafting yield is higher the higher the storage temperature. The bulk grafting involves a progressive swelling of the grafted polyacrylonitrile branches by acrylonitrile monomer via a dipole-dipole association of the -CN groups of the monomer with the -CN groups in the polymer.     

Nitrobenzene oxidation of fractions of cotton-plant dioxane lignin

Summary Analysis of the products of alkaline nitrobenzene oxidation of lignin fractions has confirmed their chemical inhomogeneity and has shown that in the various fractions the amounts of condensed syringly and guaiacyl structures differed markedly.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii No. 1, pp. 82–84, January–February, 1979.     

Floating spherical gaussian orbital (FSGO) studies with a model potential: some open-shell systems

A gaussian based model potential is used within the FSGO formalism to study a series of open-shell systems (e.g. LiH⁺, NaH⁺, Li⁺₂ and LiNa⁺). Results for calculated equilibrium geometries and dissociation energies are compared to the corresponding quantities from available all-electron ab initio studies and other more elaborate theoretical estimates. The overall agreement is quite satisfactory.     

Preliminary analysis of the composition of polysaccharide fractions

Conclusions A simple and convenient method for analyzing polysaccharide fractions isolated from natural sources has been proposed.The method is based on ion-exchange chromatography on DEAE-cellulose and gel filtration on Bio-Gels using small columns and automatic monitoring of the separation with the aid of a flow-through ultraviolet densitometer. The method is characterized by rapidity and good reproducibility.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 4, pp. 203–206, 1969     

Stereochemical features of diterpene alkaloids in acylation and alkaline hydrolysis reactions

Summary Relative difficulty of saponifying an acetoxy group at C₁ and ease of acylation of a hydroxy group in this position as compared with a hydroxy group C₁₀ has been shown for alkaloids with a lycoctonine skeleton.The anomalously easy saponification of a C₁-acetoxy group in karakolidine acetates is due to the influence of the neighboring C₁₃-hydroxy group.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 381–383, May–June, 1975.     

Synthesis of dihydrothieno[3,4-b]indoles

A new heterocyclic system — 3-imino-4-methyldihydrothieno[3,4-b]indole — was obtained by treatment of 1-methylindole-2-carboxylic acid thioamide with aldehydes or ketones in the presence of hydrogen chloride. Reactions involving saponification and acetylation of the imino group of the thieno ring and opening of the thieno ring by the action of LiAlH₄ to give a bis(indolylphenylmethyl) sulfide were carried out. A scheme is proposed in which the SH group of the thioamide adds to the carbonyl compound in the first step, after which the product undergoes intramolecular cyclization in the 3 position of indole.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1327–1331, October, 1977.     

Research on a number of substituted arylamides of dithiocarboxylic acids

Dithiomalonic acid diarylamldes are cyclized to 3,5-diarylamino-1,2-dithiolium halides by oxidation with an equivalent amount of bromine (iodine) in chloroform solution; the same amides are cyclized to 4-bromo-3,5-diarylamino-1,2-dithiolium bromides with excess bromine and to 3-arylamino-5-arylimino-1,2-dithiols in alkaline media with potassium ferricyanide. The behavior of the synthesized substituted 1,2-dithiols with respect to various reagents was studied.     

On the symmetry of iron(III) tris-acetylacetonate crystals

The crystal structure of iron tris-acetylacetonate is re-determined. Crystal data at 293 K are: a = 15.4524(5) Å, b = 13.5876(4) Å, c = 16.5729(7) Å, Z = 8; at 150 K: a = 15.2541(4) Å, b = 13.4451(3) Å, c = 16.4256(5) Å, Z = 8. The structure is molecular and comprises isolated molecules. The coordination polyhderon of iron is an almost regular octahedron, Fe-O bond lengths are 1.977–2.003 Å (293 K) and 1.982–2.006 Å (150 K). In the crystalline state, the molecules are arranged in layers, and iron atoms are located on a plane yielding an almost regular trigonal net with the Fe...Fe separations of 7.558–8.103 Å (293 K) and 7.472–8.017 Å (150 K). The adjacent layer is positioned exactly over the first one with a Fe...Fe distance of 8.303 Å (293 K) and 8.236 Å (150 K).