Conformational features of Cl3P=NC(CF3)3 and Cl3P=NCCl(CCl3)2 molecules according to results of non-empirical calculations

Non-empirical RHF/6-31G* and MP2/6-31G* quantum chemical methods are used to calculate the molecular structure of trichlorophosphazene compounds: Cl₃P=NC(CF₃)₃ (I) and Cl₃P=NCCl(CCl₃)₂ (II). The corresponding geometric parameters obtained from the calculations are compared with X-ray diffraction analysis data reported in the literature. Conformational differences between the molecules of I and II, previously found by X-ray diffraction in the crystals of these compounds, are confirmed by non-empirical calculations of the molecules in the free state. The features of their geometry caused by intramolecular interactions are discussed.     

Metal anodes oxidation rate forecasted by results of electrolysis

This work represented the results from electrolysis tests of low-melting cryolite-alumina melts at temperatures of 790 and 850°C using metal anodes based on Cu-Fe-Ni and Cu-Al. The duration of experiment was at least 72 h. With these results, oxide layer dissolution/erosion rate and anodic material oxidation depth was calculated in arbitrary units (alloy cm/year) with examples of extrapolated (forecasted) experimental data of oxidation depth and oxide layer thickness for a long period. The oxide layer formed on the anode surface by electrolysis of the studied materials was found to decelerate further oxidation all over the period of tests.     

Reaction of methyl 1-bromocycloalkanecarboxylates with zinc and 2,6-bis(arylmethylene)cyclohexanones

Methyl 1-bromocyclopentane-, 1-bromocyclohexane-, and 1-bromocycloheptanecarboxylates react with zinc and 2,6-bis(arylmethylene)cyclohexanones to afford 4-aryl-8-(arylmethylene)-5,6,7,8-tetrahydrospiro[chromene-3,1′-cyclopentan]-2(4H)-ones, 4-aryl-8-(arylmethylene)-5,6,7,8-tetrahydrospiro[chromene-3,1′-cyclohexan]-2(4H)-ones, and 4-aryl-8-(arylmethylene)-5,6,7,8-tetrahydrospiro[chromene-3,1′-cycloheptan]-2(4H)-ones, respectively.     

Selective Anodic Dissolution of Ag–Zn Alloys in the Eutectic Melt of Alkali Metal Chlorides at 300°С

Russian Journal of Electrochemistry - The peculiarities of electrochemical dealloying of two homogeneous Ag–Zn alloys in the (LiCl)0.57(CsCl)0.26(KCl)0.17 melt are studied. The zinc content...     

Physicochemical properties of 4,5-(aryl,alkyl)-3-substituted 2-aminothiophenes sulfonyl derivatives

Physicochemical properties of 4,5-(aryl, alkyl)-3-substituted 2-sulfonylaminothiophenes have been studied. The effect of the nature of the substituents in the thiophene ring on acid-base properties, solubility, and chemical stability was investigated.     

Rate of metallic anode oxidation in the course of electrolysis of cryolite-alumina melts. Derivation of basic equations

The well known oxidation law is offered as a basis for the new method that allowed predicting the service life of metallic anodes by extrapolation of the experimental results (time dependences of the substrate oxidation depth, oxide layer mass and its chemical composition) to a long-term period (a year). The suggested calculation technique allows predicting the steady state characterized by constant equal rates of metallic anode oxidation and erosion of its oxide layer and also the constant oxide layer thickness in the case when it features an ability to hinder further oxidation.     

Reaction of Reformatsky Reagents with Substituted Alkyl Esters of 2-Oxochromene-3-carboxylic Acid

Reformatsky reagents generated from alkyl esters of bromoacetic, -bromopropionic, -bromobutyric, and -bromoisobutyric acids react with alkyl esters of 6,8-dibromo-2-oxochromene-3-carboxylic acid to form alkyl esters of 6,8-dibromo-4-(1-alkoxycarbonylalkyl)-2-oxochromane-3-carboxylic acid.     

Synthesis of amides of 2-arylamino-4,6-dimethylnicotinic acid

The amides of 2-arylamino-4,6-dimethyl-2-chloronicotinic acid have been prepared. It has been shown that on account of steric hindrance on the part of the methyl group on the C₍₄₎ atom the conjugation of the amide function with the pyridine ring is broken and its influence on the mobility of the halogen is weakened, and the compound enters into a given reaction with more difficulty than its 6-monomethyl homolog.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1506–1508, November, 1992.     

Metal-form catalysts with supported active phase for deep oxidation of hydrocarbons

Catalysts based on metal foams (block porous cellular materials) with supported active phases containing oxides of transition metals have been studied in the process of deep oxidation of n-butane. Foamy metal catalysts have high activity, gas permeability and good mechanical strength.