Synthesis of Functionally Substituted Diacetylenic Alcohols and Carboxylic Acids

Diacetylenic alcohols were synthesized by the Glazer reaction of 1-alkynes with 1-alkyn--ols. p- and m-Alkadiyne bezoic acid derivatives were prepared by the Cadiot-Hodkiewicz reaction of p- and m-ethynylbenzoic acid with 1-bromoalkynes.     

Complete ozonolysis of 3-methyl-4-(prop-1-en-1-yl)cyclohexene

Complete ozonolysis of the thermal dimer of piperylene, 3-methyl-4-(prop-1-en-1-yl)cyclohexene, followed by reduction of primary peroxy compounds with dimethyl sulfide, gave 2-methyl-3-formyl-1,6-hexanedial as the major product and five-and six-membered hydroxy lactones which were formed via intramolecular cyclization of peroxides with participation of oxygen-containing functional groups.     

Cation distribution and interatomic interactions in oxides with heterovalent isomorphism: XII. Gd2Sr1? x Ca x Al2O7 solid solutions

The area of existence of Gd₂Sr_1−x Ca _x Al₂O₇ solid solutions at x ≤ 0.5 was determined by the X-ray phase analysis. It was found by full-profile X-ray structural analysis that, in contrast to La₂Sr_1−x Ca _x Al₂O₇ solid solutions, the Ca²⁺ cations occupy not only AO₉ nine-vertex fragments, but also AO₁₂ oxygen cubooctahedra. Full ordering of Sr²⁺ cations in the perovskite layer is observed at the calcium content x 0.5. Original Russian Text ? I.A. Zvereva, A.G. Cherepova, Yu.E. Smirnov, 2007, published in Zhurnal Obshchei Khimii, 2007, Vol. 77, No. 4, pp. 557–563. For communication XI, see [1].     

Complex Formation During Molybdenum Chlorination in DMF Medium

IR and EPR studies of solutions formed after molybdenum chlorination in the medium of DMF revealed the diamagnetic Mo(VI) and paramagnetic Mo(V) complexes of composition R₂[MoOCl₅], where R is [(CH₃)₂NCOH₂]⁺ (I) and [(CH₃)₂NH₂]⁺ (II). The hydrolysis of complex II was found to give dimethyl-substituted ammonium chloride.     

IR and NMR spectra, intramolecular hydrogen bonding and conformations of mercaptothiacalix[4]arene molecules and their para-tert-butyl-derivative

It is demonstrated that the introduction of p-tert-butyl groups dramatically influences the conformational behaviour of the mercaptothiacalix[4]arene molecules. Quantum-chemical computations in combination with IR and NMR spectroscopy prove that, in contrast to closely related calixarenes, the 1,3-alternate becomes a dominant conformer of p-tert-butyl-mercaptothiacalix[4]arene not only in crystal, but also in solutions and in vacuum. It is shown that the title molecules form essentially non-cooperative intramolecular hydrogen bonds: their SH groups are intramolecularly H-bonded solely to the sulfide groups bridging thiophenolic units. The enthalpy of this bonding, evaluated from Iogansen’s rule, amounts to ca. 1.5 kcal mol⁻¹ per one SH···S bond, which about four times smaller than the enthalpies of cooperative intramolecular H-bonds formed by related calixarenes and thiacalixarenes. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Esters of o-and m-carborane-C-carboxylic acids with o-and m-C-carborane alcohols

Acid chlorides of o-and m-carborane-C-carboxylic acids reacted with primary o-and m-C-carborane alcohols in anhydrous benzene to form previously unknown corresponding o-and m-carborane-containing two-and three-nuclear esters.     

Phase transformations in rapidly quenched Al–Cr–Zr alloys during heat treatment

Results from studying the effect zirconium has on solid-phase processes in aluminum–chromium alloys are presented. Rapidly quenched alloys are prepared via melt spinning. The quenching rate is ~10⁶ K/s. By means of physicochemical analysis, it is shown that doping Al–Cr alloys with zirconium improves the thermal stability of supersaturated solid solutions and stabilizes their microcrystalline structure; this hinders the coagulation of intermetallic phases and thus improves the hardness of the alloys. It is found that supersaturated solid solutions of Cr and Zr in aluminum undergo stepwise decomposition; the temperature and time parameters of each step are shown in TTT diagrams.     

Effect of protonation on the photocatalytic activity of the layered titanate Rb2Nd2Ti3O10

It was found that the contact of the layered oxide Rb₂Nd₂Ti₃O₁₀ with an aqueous solution gives rise to a protonation process, which leads to lowering the oxide photocatalytic activity in reactions of hydrogen evolution from a water-alcohol solution.

     

New derivatives of 4,5-dihydro-1<Emphasis Type="Italic">H</Emphasis>-pyrazole, 4,5-dihydro-1,2-oxazole,and pyrimidine prepared proceeding from (<Emphasis Type="Italic">E</Emphasis>)-3-[5-(4-methylphenyl)-1,2-oxazol-3-yl]-1-ferrocenylprop-2-en-1-one

Condensation of acetylferrocene with 5-phenyl(4-methylphenyl)-1,2-oxazole-3-carbaldehydes afforded (Е)-3-[5-phenyl(4-methylphenyl)-1,2-oxazol-3-yl]-1-ferrocenylprop-2-en-1-ones. Reactions of (Е)-3-[5-(4-methylphenyl)-1,2-oxazol-3-yl]-1-ferrocenylprop-2-en-1-one with semicarbazide, thiosemicarbazide, and hydroxylamine led to the formation of 5-[5-(4-methylphenyl)-1,2-oxazol-3-yl]-3-ferrocenyl-4,5-dihydro-1H-pyrazole- 1-carboxamide, 5-[5-(4-methylphenyl)-1,2-oxazol-3-yl]-3-ferrocenyl-4,5-dihydro-1H-pyrazole-1-carbothioamide, and 5-(4-methylphenyl)-3'-ferrocenyl-4',5'-dihydro-3,5'-bi-1,2-oxazole respectively. Reactions of (Е)-3-[5-(4-methylphenyl)-1,2-oxazol-3-yl]-1-ferrocenylprop-2-en-1-one with guanidine and thiourea result in 4-[5-(4-methyl-phenyl)-1,2-oxazol-3-yl]-6-ferrocenylpyrimidin-2-amine and -2-thione respectively.     

VUV spectrum of the barrier discharge in a krypton-xenon mixture

VUV spectra of a barrier discharge in a krypton-xenon mixture at the pressure P=400 hPa were experimentally studied. The xenon addition was varied in a range of 0.01–1%. The supply voltage frequency was 20 kHz. The form of spectra and their evolution at different xenon impurity concentrations were analyzed by solving the system of nonlinear differential equations simulating the main processes taking place in the active phase of a discharge and in the afterglow. The analysis supports the results obtained earlier and qualitatively describes the experimental spectra.