ZrO2–Sc2O3 Solid Electrolytes Doped with Yb2O3 or Y2O3

Russian Journal of Electrochemistry - The effects of the Y2O3 and Yb2O3 co-doping impurities on the transport characteristics and stabilization of the cubic phase in solid solutions based on...     

Studies with arylhydrazonopyridinones: Synthesis of new arylhydrazono thieno[3,4-c]pyridinones as novel D2T2 dye class; classical verse green methodologies

A variety of arylhydrazonopyridinones were prepared via heating cyanoacetamides with ethyl acetoacetate in absence of solvent under reflux conventionally or ultrasound irradiation or in a microwave oven. The formed products 5 and 6 could be readily converted to thienopyridones. Attempted addition of the latter to electron poor olefins afforded only arylhydrazonopyridinones.     

Structure and phase composition studies of partially stabilized zirconia

Zirconia single crystals doped with 2.8, 3.2, 3.7, and 4.0 mol % of Y₂O₃ have been studied. The phase composition and structure have been studied by X-ray diffraction analysis and transmission electron microscopy. It has been established that all investigated samples has two ZrO₂ tetragonal phases with tetragonality c/a = 1.006–1.007 and c/a = 1.014–1.015 independent of the stabilizing impurity content. The former phase is not transformed, whereas the latter is transformed into a monoclinic one. In all cases the samples have a developed twin structure. Twinning hierarchy is observed: there are first-, second-, third-order, etc., twins, each of them containing the next-order twins inside them. Elastic stress relaxation occurs by twinning rather than by generation of dislocations. The stabilizing impurity content affects the structure nonmonotonically; the minimum dimensions of the twin lamellas refer to the Y₂O₃ concentration of 3.2 mol %.     

Microwave assisted condensation reactions of 2-aryl hydrazonopropanals with nucleophilic reagents and dimethyl acetylenedicarboxylate

The reaction of methyl ketones 1a-g with dimethylformamide dimethylacetal (DMFDMA) afforded the enaminones 2a-g, which were coupled with diazotized aromatic amines 3a,b to give the corresponding aryl hydrazones 6a-h. Condensation of compounds 6a-h with some aromatic heterocyclic amines afforded iminoarylhydrazones 9a-m. Enaminoazo compounds 12a,b could be obtained from condensation of 6c with secondary amines. The reaction of 6e,h with benzotriazolylacetone yielded 14a,b. Also, the reaction of 6a,b,d-f,h with glycine and hippuric acid in acetic anhydride afforded pyridazinone derivatives 17a-f. Synthesis of pyridazine carboxylic acid derivatives 22a,b from the reaction of 6b,e with dimethyl acetylenedicarboxylate (DMAD) in the presence of triphenylphosphine at room temperature is also reported. Most of these reactions were conducted under irradiation in a microwave oven in the absence of solvent in an attempt to improve the product yields and to reduce the reaction times.     

Studies with enaminones: Formation of a N,O‐cyclicacetal on coupling of 3‐dimethylamino‐1‐hydroxyphenyl‐2‐propenone with arenediazonium salts

Coupling the title compound 3 with arenediazonium salts affords the arylhydrazonochromones 6 . The latter compounds react with hydrazine hydrate to yield novel pyrazoles 11 .     

Spectral-luminescence characteristics of alkali-free silicate glasses with a high concentration of terbium and tin

We discovered and investigated sensitization of the luminescence of Tb³⁺ ions by Sn(II) oxocomplexes in highly activated alkali-free silicate glass. We show that the quantum yield of the luminescence sensitization in this glass can be increased by UV irradiation. The possibility for the use of such glasses as luminescing light filters for YAG-Nd laser quantrons is noted. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 1, pp. 83–86, January–February, 1998.     

Green chemistry: A facile synthesis of polyfunctionally substituted thieno[3,4-c]pyridinones and thieno[3,4-d]pyridazinones under neat reaction conditions

A facile, solvent free, ecofriendly approach for the synthesis of pyridine-2,6-diones 4a–d, pyridazinone derivatives 8a–c and thienoazines 6 and 9 is herein described employing neat reaction conditions under both microwave and ultrasound irradiations. This solventless methodology is environmentally benign as it completely eliminates the use of solvent from the reaction procedure.     

Effect of Heat Treatment on the Thermal Conductivity of Single Crystals of ZrO2-Based Solid Solutions Stabilized with Scandium and Yttrium Oxides

Physics of the Solid State - The effect of heat treatment at 1000°C for 400 h on the thermal conductivity of zirconium dioxide crystals stabilized with scandium oxide...     

Die Verzerrung des Deuterons bei der elastischenn-d-Streuung

By measuring the electrical resistance and the magnetisation of nickel, charged with cathodic hydrogen, no desorption was found below 190°K. The change of resistance between 4° and 300°K and the residual resistance could be observed in the different states of desorption. Absorbed hydrogen strongly increases the residual resistance. By separating the residual from the total resistance one receives a temperature-dependent section in which the values are lower than those of pure nickel. The results are discussed in connection with theoretical considerations ofMott.     

Specific Features of the Local Structure and Transport Properties of ZrO2–Sc2O3–Y2O3 and ZrO2–Sc2O3–Yb2O3 Crystals

Optics and Spectroscopy - The specific features of the local structure of ZrO2–Sc2O3–Y2O3 and ZrO2–Sc2O3–Yb2O3 crystals are revealed by optical spectroscopy using the Eu3+...