Medium effect on the direction of the reaction of 3-chloro-1,3-diphenyl-1,2-propanedione with ortho-phenylenediamine

The reaction of 3-chloro-1,3-diphenyl-1,2-propanedione (I) with ortho-phenylenediamine in acetic acid gave 2-phenyl-3-(-chlorobenzyl)quinoxaline (II). This reaction in methanol with MeONa gave 2-(-hydroxybenzylidene)-3-phenyl-1,4-dihydroquinoxaline (VI).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1660–1662, July, 1991.     

Reaction of the N,N-dimethylamide and methyl ester of 3-phenyl-3-chloro-2-ketopropionic acid with triphenylphosphine

Conclusions The dimethylamide of 3-phenyl-3-chloro-2-ketopropionic acid reacts with Ph₃P to give -(N,N-dimethyloxamoyl)benzyltriphenylphosphonium chloride. In the presence of methanol, this reaction gives dimethyl(phenylpyruvoyl)amide and Ph₃PO.2. The methyl ester of 3-phenyl-3-chloro-2-ketopropionic acid reacts with Ph₃P to give methoxycarbonylstyryloxytriphenylphosphonium chloride, which, upon heating in benzene at reflux, gives methyl -chlorocinnamate and Ph₃PO.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1395–1396, June, 1989.     

Polarity and polarizability of alkoxyacetylenes

Conclusions The dipole moment of the C_sp-O bond in alkoxyacetylenes is 1.3 D and is directed toward the carbon atom. The values for the major semiaxes in the polarizability ellipsoid of the HC=CO fragment are b_L=4.60 and b_T=bv=2.77 ų.Translated from Izvestiya Akaderaii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1198–1200, May, 1986.     

Electron transfer in nucleophilic vinyl substitution reactions involving bromovinyl sulfones

Conclusions It was shown that the reaction of phosphorous hexaalkyltriamides with-bromovinyl aryl sulfones proceeds via the step of electron transfer with the formation of ion-radicals.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2785–2787, December, 1981.     

Optoelectronic effects in p-CdGeAs2 single crystals and structures based on them

Spectra of inelastic light scattering by optical phonons in p-CdGeAs₂ single crystals were obtained for the first time. The observed clear polarization dependence and the absence of any appreciable dependence of the intensity and frequency of the observed lines when the sample is swept in ≈300 μm steps indicates these CdGeAs₂ single crystals grown by directional crystallization from a near-stoichiometric flux, are of high quality and homogeneous. The type of symmetry of the observed phonon lines is interpreted and it is shown that the force constants in CdGeAs₂ and CdSnP₂ crystals differ slightly. Temperature dependences of the electrical conductivity and the Hall constant were studied in oriented homogeneous p-CdGeAs₂ single crystals. It was established that the conductivity of these crystals is determined by the deep acceptor level E _A=0.175 eV and has the degree of compensation 0.5–0.6. The temperature dependence of the Hall mobility reflects the competition between impurity and lattice mechanisms of hole scattering. The photosensitivity of In/CdGeAs₂ surface barrier structures reaches 20 μA/W at T=300 K and remains at this level within the fundamental absorption of CdGeAs₂. It is concluded that these structures may be used as wide-band photoconverters for natural light and as selective photoanalyzers for linearly polarized radiation. Fiz. Tverd. Tela (St. Petersburg) 40, 212–216 (February 1998)     

Critical Effect of the Length of Counterions in Mesogenic Lanthanide Complexes on the Electro-Optical Properties of Their Melts

Isotropic melts of nine metallomesogenic complexes with a smectic-А phase have been studied by the electric birefringence method. Complexes include Dy, Tb, Gd, and Er rare-earth ions, Schiff bases as ligands, and alkyl sulfate or nitric-acid counterions. It has been shown for the first time that both the magnitude and the sign of the electro-optical effect in the isotropic phase for the studied substances are determined by the length of counterions. This means that the dielectric anisotropy of smectic lanthanide complexes can vary widely depending on counterions: it can be positive, negative, or close to zero.