Application of IR spectroscopy in the analysis of the woody-fibrous mass in the process of hydrolysis

The possibility has been shown of using IR spectroscopy in the investigation of the changes in the polysaccharide component of wood in the process of acid hydrolysis. The method of determining the relative optical density (ROD) was used for the quantitative evaluation of the changes in the functional groups of the lignocellulose.Deceased.Siberian Scientific Research Institute of Cellulose and Board, Bratsk. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 683–687, September–October, 1990.     

Investigation of the structure and energetics of β-diketonates. II. Structure of the bis-dipivaloylmethanatocopper(II) molecule by gas phase electron diffraction

Ivanovsk State University. Translated from Zhurnal Strukturnoi Khimii, Vol. 33, No. 6, pp. 76–83, November–December, 1992.     

Gas electron diffraction study of the molecular structure of NbCl4

The structure of the NbCl₄ molecule is studied experimentally by the synchronous electron diffraction and mass spectrometry methods. The model molecular geometries of C_2v, C_3v, D_2d, and T_d symmetries are verified. The advantages of the tetrahedral model over the other models are established. The thermally averaged parameters of the effective configuration of the NbCl₄ molecule are as follows: r_g(Nb?Cl)=2.279(5) Å, l(Nb?Cl)=0.073(2) Å, r_g(Cl?Cl)=3.692(17) Å, l(Cl?Cl)=0.275(11) Å, ∠_g(Cl-Nb-Cl)=108.2(5)°, and δ(Cl?Cl)=0.030(19) Å.     

Ergodic properties of integral points on ellipsoids of genus

The ergodic and the intermixing theorems of Yu. V. Linnik (Mat. Sb.,43, No. 2, 257–276) are generalized to arbitrary positive quadratic forms of genus of , where Ω > 1 is an odd number, of invariants [Ω,1], defined by the character for all prime numbers ρ¦Ω. One obtains estimates for the remainder term. The method of proof is simplified.     

Influence of chemical modification of the surface of polyethylene with phosphorus, boron, titanium, vanadium, and silicon halides on its vapor permeability

The influence of a gas-phase chemical modification of low-density polyethylene with volatile halides of various elements [PCl₃, TiCl₄, VOCl₃, BBr₃, and Si(CH₃)₂Cl₂] on the surface layer morphology and vapor permeability of polymeric formulations was examined by atomic-force microscopy, chemical analysis, and adsorption method.     

Synthesis of chloro aldehydes of the heterocyclic series

A method was developed for the preparation of 4-chloro-5-formylimidazolones, Δ⁴-thiazolinones, and 4-chloro-5-formyluracils by reaction of 4-azolidones or barbituric acids with dimethylformamide and phosphorus oxychloride.     

Investigation of structure and energetics of β-diketonates. III. Conformational study of copper(II) dipivaloylmethanate. Determination of the internal rotation barrier oftert-butyl groups

Ivanovo State University. Ivanovo Chemical Engineering Institute. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 4, pp. 135–138, July–August, 1994.     

Synthesis and Properties of Copolymers Having Polyconjugated Blocks in the Macromolecules. III Thermal Behavior of Polyisoprene-Containing Polyazophenylene Fragments in the Main Chains

The thermal and thermooxidative stability of polyisoprene containing polyazophenylene fragments of different composition was investigated. Elevated inhibiting activity of polyazophenylene -methane fragments was found to be caused by the intramolecular synergism due to the combination of the reaction of peroxy radicals with mobile hydrogen atoms of methylene bridge groups and decomposition of hydroperoxides under the influence of polyconjugated blocks.     

Extraction and separation of lanthanides from aqueous chloride and nitrate media using mixtures of binary extractants based on secondary and tertiary amines

1. Download : Download high-res image (97KB)
2. Download : Download full-size image

     

IR spectral and quantum-chemical studies of binary extractants

The composition and ionic character of formation of binary extractants based on quaternary ammonium bases and organic acids were confirmed using spectral and quantum-chemical methods, the structures of the binary extractants were obtained. The energy of bond between cation and anion in molecules of the binary extractants was determined, it is by an order of magnitude higher than the energy of H bond and close to the energy of chemical (ionic) bond.