Iodination of 6-aryl-2-pyrones

The iodination of 6-aryl-2-pyrones with iodine chloride in glacial acetic acid leads to the corresponding 3-iodo derivatives. 3-Cyano-6-phenyl-2-pyrone and 3-phenylethynyl-6-phenyl-2-pyrone were obtained by replacement of the iodo group by cyano and phenylethynyl groups.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 616–618, May, 1884.     

Differentiable mappings of affine spaces into manifolds of <Emphasis Type="Italic">m</Emphasis>-planes in a multidimensional Euclidean space

In this paper we consider a differentiable mapping of a p-dimensional affine space into the differentiable manifold $ \mathfrak{M} $ \mathfrak{M} _N of all centered m-planes in an n-dimensional Euclidean space. We pay special attention to describing geometric images defined by a fundamental geometric object of the mentioned mapping.     

Di- and tri(2-pyron-6-yl)arenes

Condensation of di- and triacetylarenes with 1,1,1,3-tetrachloro-3-alkoxypropanes or ,-dichloroacrolein in acidic media gave a number of (dichloropentadienyl)- and tris (dichloropentadienyl)-substituted aryl ketones, which, in the case of acetic acid in the presence of phosphoric acid, are converted to the corresponding di- and tri(2-pyron-6-yl)arenes. It was observed that nitric acid has an oxidation effect on 2-pyrones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 897–901, July, 1977.     

Halo-2-pyrones in the Ullmann reaction. 1

The Ullmann reaction was used for the first time for the synthesis of poly-2-pyrones. 3-Halo-2-pyrones were obtained by halogenation of the corresponding 6-aryl-2-pyrones. The Ullmann reaction was carried out by heating a mixture of the 3-halo-2-pyrone with activated copper in a stream of an inert gas. The reaction products were the previously undescribed bis-2-pyrones, in which the -pyrone rings are interlinked by means of the 3-C atoms.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 173–176, February, 1979.     

Novel liquid crystal compounds,derivatives of 2-pyrone

6-(4-n-Hexyloxyphenyl)- and 6-(4-n-decyloxyphenyl)-2-pyrones, which possess smectic and nematic mesomorphism, were synthesized.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1793–1794, October, 1994.     

On a Hypothesis on the Molecule Vacancies in PbTe

The temperature dependence of the current carriers mobility in SnTe(I) and PbTe (I) synthesized in presence of SnI₂ or PbI₂ respectively was studied. An experimental formula was established, showing that current carriers scattering in SnTe(I) is due to vacancies at constant Hall coefficient. For PbTe (I) crystallized from tellurium solution by traveling heater method the mobility is high (between 2.10⁴ and 4.10⁴ cm²/Vs) and the Hall coefficient is constant within the interval 77 K–450 K. Only within 77 K–160 K interval the current carriers scattering is due to vacancies. A hypothesis is proposed based on the presence of molecular vacancies (V_pbTe). These vacancies do not change electron gas concentration but do change the carriers mobility. Specimens with a negligibly low lead atoms vacancies Concentration were investigated. An empirical expression is established which shows that their mobility depends on molecular vacancies concentration and explains observed weak temperature influence upon carriers mobility. These results are obtained only from Hall coefficient and electric conductivity measurements within the 77 K–160 K temperature interval.