On the solidification of the Fe50Cr15Mo14C15B6 bulk-amorphized alloy

Investigations of the effect of the initial liquid phase state on the processes of solidification in Fe₅₀Cr₁₅Mo₁₄C₁₅B₆ bulk-amorphized melts have been carried out by differential thermal analysis, X-ray structural analysis, metallography and viscosimetry. The anomalies caused by changing the relation of the atom microgroups of boride and carbide types have been discovered for the first time in polytherms of the melt viscosity in the vicinity of 1653 K and 1793 K. The structural changes observed in the liquid phase result in anomalies in the Fe₅₀Cr₁₅Mo₁₄C₁₅B₆ melt supercooling behaviour and a change in the crystallization mechanism. Structural transformation temperatures, can be considered to be an additional factor in the search for promising alloys with optimized glass forming abilities and enhanced service properties.     

Conformational Analysis and Study of Hydrogen Bonding of Iodobicycloheptanyl-N′-(trifluoromethanesulfonyl) Acetimidamides

Russian Journal of General Chemistry - Structure of iodobicycloheptanyl-N′-(trifluoromethanesulfonyl) acetimidamide epimers and its self-associates in crystal, solution and gas phase was...     

Conformations and Self-association of Trifluoro-N-(3-formylcyclohept-2-en-1-yl)methanesulfonamide

The structure of trifluoro-N-(3-formylcyclohept-2-en-1-yl)methanesulfonamide and its self-association in solution have been studied by IR spectroscopy and quantum chemical methods [B3LYP/6-311G(d,p), AIM]; proton affinities of basic centers in its molecule have been evaluated. Trifluoro-N-(3-formylcyclohept-2-en-1-yl)methanesulfonamide in inert solvents forms cyclic dimers, whereas in crystal chain associates are more likely to be formed via hydrogen bonding between the NH and C=O groups of neighboring molecules. The carbonyl group in the title compound undergoes protonation only by the action of very strong trifluoromethanesulfonic acid. Weaker acids give rise to solvate H-complexes at the NH, C=O, and S=O groups. The topology of hydrogen bonds in dimers of different types has been analyzed in terms of the AIM theory.     

Structure and intramolecular hydrogen bonds in Bis(trifluoromethylsulfonylamino)methane and N-[(trifluoromethylsulfonyl)aminomethyl]acetamide

Bis(trifluoromethylsulfonylamino)methane in an inert medium exists as an equilibrium mixture of monomeric forms with various types of intramolecular hydrogen bonds, whose population depends on the polarity of the medium. The energetically most favorable form is a symmetrical form containing two N-H...O=S bonds. Less stable are the isomer with two N-H...F-C bonds and the unsymmetrical isomer with two different hydrogen bonds. N-[(Trifluoromethylsulfonyl)aminomethyl]acetamide contains one intramolecular intramolecular N-H...O=C hydrogen bond and preserves ability for self-association.     

Characteristic properties of the system of equations of a shear flow with nonmonotonic velocity profile

Institute of Hydrodynamics, Russian Academy of Sciences; Novosibirsk State University, Novosibirsk 630090. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizka, Vol. 36, No. 3, pp. 53–59, May–June, 1995.     

Assembling of 3,6-diazabicyclo[3.1.0]hexane framework in oxidative triflamidation of substituted buta-1,3-dienes

Reaction of trifluoromethanesulfonamide (triflamide) CF₃SO₂NH₂ with 2,3-dimethylbuta-1,3-diene (2) and 2,5-dimethylhexa-2,4-diene (3) in the oxidative system (t-BuOCl+NaI) results in the formation of 2,4-dimethyl- or 2,2,4,4-tetramethyl-3,6-bis(triflyl)diazabicyclo[3.1.0]hexane through two successive heterocyclizations. Reaction of diene (3) with arenesulfonamides ArSO₂NH₂ (Ar=Ph, Tol), stops at the formation of the product of oxidative 1,4-addition, N,N′-(2,3-dimethylbut-2-ene-1,4-diyl)diarenesulfonamides, providing evidence of the essential difference between the reactivity of triflamide and arenesulfonamides.     

Conformational structure of N-(silylmethyl)anilines PhNHCH2SiMe n (OEt)3-n (n = 0–3)

As show the data of IR spectroscopy and quantum-chemical calculations (B3LYP/6-311+G**), N-(silylmethyl)anilines PhNHCH₂SiMe _n (OEt)_3?n in inert media have an intramolecular hydrogen bond NH?OSi. N-[(Trimethylsilyl)methyl]aniline PhNHCH₂SiMe₃ in inert solvents exists as a mixture of two conformers close in energy.     

Molecular Structure of Complexes with Bifurcated Hydrogen Bond: III. Solvate H-Complexes Formed by Trifluoromethanesulfonamide and Its Cyclic Dimer

According to the data of IR spectroscopy, dielcometry, and B3LYP/6-31G* quantum-chemical calculations, trifluoromethanesulfonamide homoassociates in weakly basic protophilic media are converted into 2 : 1 solvate H-complexes. Cyclic trifluoromethanesulfonamide dimer decomposes in heteroassociate with dioxane with a composition of 1 : 3. Cyclic trifluoromethanesulfonamide dimer with dioxane forms a 1 : 4 H-complex with bifurcated (three-center) hydrogen bond involving the bridging hydrogen atom of the NH group (NH?O).     

Facile one-pot synthesis of 5-substituted isoxazoles and pyrazoles through microwave-promoted intramolecular cyclization of γ-hydroxyalkynal oximes and hydrazones

Simple and efficient one-pot synthesis of 5-substituted isoxazoles and pyrazoles has been developed. The formation of the target isoxazoles and pyrazoles is initiated by 1,2-nucleophilic addition of generated in situ hydroxylamine or hydrazine to α-acetylenic γ-hydroxyaldehydes with further intramolecular cyclization of the adducts. The protocols are associated with readily available substrates, simple procedure, short reaction time, and moderate to high yields.     

Structure of Barbituratobis(2,2'-Dipyridyl)copper(II) Heptahydrate

Russian Journal of Coordination Chemistry - The structure of the complex [Cu(Bipy)2(BA)] ? 7H2O (I), where Bipy is 2,2'-dipyridyl, and BA2– is the barbituric acid anion (H2BA), is...