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[en] The equilibrium of distribution of Yb(3) and Lu(3) between chloroform and the aqueous phase in the presence of cupferron (the ammonium salt of N-nitrosophenylhydroxylamine) were studied as a pH function of the aqueous phase and the concentration of N-nitrosophenylhydroxylamine (HL). The stability constants for the LnLn(3-n)complexes (n = 1/3) being formed in the aqueous phase were established, as well as the equilibrium constants of the extraction reaction Ln(H2O)m3++3HL(0) rightleftdblarrow LnL3(0) +3H++mH2O(Ln3+ = Yb, Lu), two-phase stability constants for the LnL3 complexes, pH0,5 and the separation factor Lu(3) from Yb(3). (Author)
[en] Full text: Radiation-chemical treatment is considered as a perspective method of water purification from chloroform. It provides the high level of purification (98%) of water solutions from chloroform and other chlorine-containing compounds. Meanwhile, other chlorine-containing products can be formed during the process of chloroform degradation and as a result of it the quality of water can change. As shown, at high contents of chloroform after certain adsorbed dose the forming products are reducing till their full disappearing. At small contents of chloroform in the studied interval of doses di-chlor-methane is forming. Differences of dose dependences of by products at various contents of chloroform can be connected with the transition from radical mechanism to chain reaction at high concentrations of chloroform in solutions saturated oxygen. ρΗ-solutions also reduces during the radiation till ρΗ=1, although this reduction the depends on initial concentration of chloroform
[en] The specific rates of solvolysis of 1- naphthyl chloroformate (1-NaphOCOCl, 1) and 2-naphthyl chloroformate (2-NaphOCOCl, 2) have been determined in a wide range of solvents at 2.0 and 10.0 .deg. C. These give a satisfactory correlation over the full range of solvents when the extended (two-term) Grunwald-Winstein equation is applied. The sensitivities (l and m-values) to changes in solvent nucleophilicity (NT) and solvent ionizing power (YCl) are similar to those reported previously for solvolysis of phenyl chloroformate, which has been suggested to proceed through an addition-elimination mechanism with the addition step being rate determining. For four representative solvents, studies were made at several temperatures and activation parameters determined. These observations were also compared with those previously reported for phenyl chloroformates and naphthoyl chlorides
[en] Intermolecular bonding between 3-aminophenol and two halomethanes, namely fluoroform and chloroform, was quantum mechanically investigated. Several low-energy structures are found, and all geometries within 1 kcal/mol show π-hydrogen bonds between the aromatic ring and the hydrogen atom of the halomethane. The C H stretching frequency of halomethane involved in the π-hydrogen bond is blue-shifted, and the amount of blue shift is the largest with the most stable isomer and decreases with decreasing stability. Binding energy, infrared intensity, and dipole moment as a function of relative stability are also reported. This study forms another example of a blue-shifting hydrogen bond, or an anti-hydrogen bond
[en] A method has been developed, optimised and adopted for the determination of boron in wax samples. The methodology involves leaching of boron from the sample with 10% 2-ethyl hexane 1,3 diol in chloroform, its stripping from the organic phase with 0.5 M NaOH, separation of boron employing batch extraction with 10% EHD in CHCl3 and quantification by spectrophotometry using curcumin. Precision of the method is 10%. (author)
[en] This paper reports on a substoichiometric extraction of Ag(I) by S-benzyl dithiocarbazate into chloroform. The method has been applied to the estimation of silver in different rock samples, adopting the principle of isotope dilution analysis.
[en] The possibility is considered of optimizing the hydrophobic properties of metal–organic framework HKUST-1 (Сu2(btc)3, btc = benzene-1,3,5-tricarboxylate) using chloroform as a component of the reaction medium during synthesis. Using this modified technique to prepare the material helps to enhance its textural and structural characteristics.
[en] Reaction of [(bpy)Pd](PF_6)_2 (bpy = 2,2'-bipyridine) with racemic bis(isonicotinoyl)-1,1'-bi-2-naphtholate (L) in acetone, and followed by addition of chloroform and solvent evaporation allows to form amorphous micro-bowl morphology consisting of [(bpy)PdL]_2(PF_6)_4 without any template or additive. In contrast, the reaction and recrystallization in acetone for 1 week produce parallel-piped single crystals consisting of [(bpy)_3Pd_3(μ_3-HPO_4)_2](PF_6)_2. The formations of micro-bowl and parallel-piped single crystal morphologies appear to be primarily associated with the kinetic and thermodynamic control, respectively. The formation of micro-bowls may be attributed to eruption of organic solvents. Cosolvent effects and chemical properties on the formation of micro-bowl morphology have been observed
[en] Highlights: • Adsorption properties of chloroform molecule on N-doped and Al-doped graphene are studied theoretically. • The p-p orbital coupling between Al and Cl atom is stronger than those of N and Cl atoms in the adsorption systems. • Al-doped graphene is more sensitive to the adsorption of chloroform molecule. Adsorption properties of chloroform (CHCl3) on pristine graphene, N-doped graphene and Al-doped graphene are studied by using density functional theory (DFT) calculations. Our calculations reveal that there are higher charge transfer and smaller adsorption distance and bigger adsorption energy when CHCl3 is adsorbed on Al-doped graphene comparing with adsorptions on pristine graphene and N-doped graphene. The p-p orbital coupling between Al and Cl is stronger than those of CCl and NCl, which suggests that Al-doped graphene is more sensitive to the adsorption of CHCl3. Al-doped graphene can be a good candidate for sensors or catalyst to detect and adsorb CHCl3.