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Том 472, № 2 (2017)
- Год: 2017
- Статей: 4
- URL: https://journals.rcsi.science/0012-5016/issue/view/9209
Physical Chemistry
Oxidation of styrene epoxide–acid binary system and styrene epoxide–acid–amine ternary system catalyzed by Co(II) salts
Аннотация
The Co(II) salt (nitrate, chloride)-induced acceleration of styrene epoxide (SE) consumption and oxidation by molecular oxygen in acetonitrile solutions of three- and four-component systems, SE–acetic acid–cobalt salt and SE–acetic acid–cobalt salt–aniline, was found and investigated. The heterolytic epoxide ring opening in SE and homolysis (oxidation) catalyzed by cobalt salts can be accomplished in the presence of acid co-catalyst. The competition between homolysis and heterolysis processes in the presence of metal-containing catalyst was discovered for the first time for this type of system. The cobalt catalyst is deactivated during the styrene epoxide conversion.
19-22
Quantum-chemical study of structural and electronic properties of a new tin monosulfide polymorph π-SnS
Аннотация
By means of the density functional theory (DFT) method, the electronic structure of the new tin monosulfide polymorph π-SnS has been calculated, its unit cell parameters have been optimized, and the relative enthalpy of formation and bulk modulus have been evaluated and compared with known and well-characterized crystalline and two-dimensional SnS modifications. It has been demonstrated that the π-SnS polymorph ranks next in stability to thermodynamically stable α-SnS. The new modification is predicted to be a semiconductor with a wider band gap than for α-SnS. It has been shown that identification of π-SnS in nanocrystalline SnS samples by X-ray crystallography could be considerably complicated by overlapping with broadened reflections of α-SnS.
23-26
IR spectroscopic study of the structure of isotactic polypropylene deformed by the crazing mechanism
Аннотация
The deformation of isotropic isotactic polypropylene with a spherulitic initial structure has been studied. Fourier transform IR spectra of polypropylene deformed to various stretch ratios in air and in a physically active medium have been recorded. From the spectroscopy data, the dichroic ratios and orientation functions have been calculated for the amorphous and crystalline polypropylene phases. It turned out that the orientations of macromolecules in the amorphous and crystalline polypropylene phases change identically while stretching in a physically active (water–ethanol) medium. However, the deformation in air leads to a more pronounced orientation of macromolecules in the crystalline phase as compared with the orientation in the amorphous phase. The maximum values of the orientation function in the deformation in air coincide with the stretch ratio at the yield point. This is how a physically active medium acts in crazing in comparison with shear deformation in air.
27-31
32-35