Kinetics of decomposition of the liquid phase of the ternary system LiOH-H2O2-H2O in the presence of the solid phase of Li2O2 · H2O

The kinetics of decomposition of hydrogen peroxide in the liquid phase of the ternary system LiOH-H₂O₂-H₂O was studied in the presence the solid phase of Li₂O₂·H₂O and without it. The main kinetic parameters of the processes studied were determined.     

Calculated vibrational structure of the first band of the photoelectron spectrum of HO 2 − and the electron affinity of HO2

The vibrational structure of the first band of the photoelectron (PE) spectrum of HO ₂ ^? and DO ₂ ^? has been calculated on the basis of (slightly modified) ab initio potentials. The best agreement with the experimental spectrum of HO ₂ ^? is obtained for a vibrational temperature of ca. 600 K. “Peak D”, which has been under debate in earlier work, is composed of two transitions, with the “hot” transition 3 ₁ ¹ being more intense than the adiabatic transition. Since thev ₂ bending mode of DO₂ has significant OO stretching character, the vibrational structure of the PE spectrum of DO ₂ ^? is more complex than that of HO ₂ ^? . Large-scale RCCSD(T) calculations of the equilibrium electron affinity of HO₂ yield 1.058 eV which agrees with the experimental value of 1.044 ± 0.020 eV.     

Topology of the electron density of multicenter bonding in the anion TCNE2 2−

For TCNE₂ ^2? the role of bond paths in the electron density is emphasized to show that the anion contains multicenter bonding interactions across 4 central carbon atoms conferring inherent stability to it, consistent with experimental, and theoretical studies of other authors.     

Influence of NO on the Reduction of NO2 with CO over Pt/SiO2 in the Presence of O2

Reduction of NO2 with CO in the presence of NO and excess oxygen, a model mixture for flue gas, over a 0.1% Pt/SiO2 catalyst was studied. The related reaction mechanisms, such as oxidation of CO and NO, were discussed. It was found that there was a narrow temperature window （180-190 ℃） for the reduction of NO2 by CO. When the temperature was lower than the lower limit of the window, the reduction hardly occurred, while when the temperature was higher than the upper limit of the window, the direct oxidation of CO by O2 occurred and thereby NO2 could not be effectively reduced by CO. The presence of NO shifted the window to higher temperatures owing to the inhibition effect of NO on the activation of O2 on Pt, which made it possible to reduce NO2 by CO in flue gas.     

Spectroscopic Study of the Interaction of Bu_2SnCl_2 with EHPG

A number of Sn (Ⅳ)complexes have been synthesized since 1980 and tested its anticancer activity1. The simplest complex Bu2SnCl2 has activity to P388 tumor cells. Several metal complexes such as Ru-ind (trans-indazolium (bisindazole) tetrachloro- ruthenate (Ⅲ)) had used transferrin as a drug delivery system, the complexes still exhibit high antitumor activity and lower toxicity2. We use EHPG as a model ligand3 to study the interaction between Bu2SnCl2 and EHPG. EHPGAt first, we stud…     

Temperature dependence of the substrate selectivity in the hydroxylation of alkylbenzenes in the H2O2−H2SO4 system

The substrate selectivity in the hydroxylation of methylbenzenes in the H₂O₂−H₂SO₄ (70 wt.%) system was studied at 15–55 °C. The activation entropy correlates with the basicity of the arenes, while the substrate selectivity and activation enthalpy correspond both with the basicity and ionization potentials of ArH. We concluded that the structure of the reaction transition state is intermediate between a charge transfer complex and σ-complex. L. M. Litvinenko Institute of Physical Organic and Coal Chemistry, National Academy of Sciences of Ukraine, 70 R. Lyuksemburg ul., Donetsk 340114, Ukraine. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 35, No. 1, pp. 39–43, January–February, 1999.     

Electronic structure of the doped SnO_2

SnO2 doped with La, Ce, Sm, Zn, Ca, Al and Sb was prepared by sol-gel technique and characterized by TEM, BET, XPS and XAES. The effect of the dopants on the grain sizes of SnO2 was described and especially the effect of dopants on the distribution of the electronic state density (DESD) of Sn4d orbital was studied deeply by using X-ray-induced Auger electron spectros-copy (XAES). It was observed that the dopants could influence not only the grain sizes of SnO2 but also electronic structure of SnO2, as well as the stability of the doped SnO2 samples. The experiment results indicated that the structure and stability of SnO2 film could be improved by the chemical modification of the dopants.     

Synthesis and Structure of the Complexes of 2-Alkoxycarbonylalkyltin Trichlorides with 2-Salicylideneaminophenol

SinceHutton]developedanovelr0utet0preparationofthe2-alkoxycarbonylalkyltintrichIorides,R'OCOCHRCH,SnCI,(l),lhavereceivedconsiderableattenti0nbecauseofthevarietyofcoordinationgeometriesaboutthetinatom.2-'Previ0usly,wehadre-portedtheadducts0flwithneutraIdonorssuchasDMSO,HMPA,bpyandphen.'-'Inthispaper,wereportthesynthesis0fthecomplexes0flwithnegativebivaIentligandderivedfr0m2-salicylideneamin0phenop(H2L),R'OCOCHRCH,SnClL(R=H,Me,R'=Me,Et,n-Pr,Allyl,n-Bu),andthecrystaIstructureof…     

Semiconductor photoinduced cycloreversion of the dimer of methyl 2-naphthoate

The dimer of methyl 2-naphthoate (1) has been found to undergo efficient cyclorever-sion to its monomer, methyl naphtha)ene-2-carboxylate (2) on illuminated ZnO and TiO2 but not on CdS. An electron transfer and cation radical chain mechanism is proposed. Quantum yields, solvent effect, the role of oxygen, and the quenching of the reaction were investigated, and were consistent with the proposed mechanism.     

Features of the Morphology of 2-Hydroxyethyl Acrylate ω-Polymer

Ω-Polymer of 2-Hydroxyethyl acrylate (HEA) with nanoporous morphology is formed and characterized. Some kinetic peculiarities and mechanism of HEA low-temperature ω-polymerization is discussed. It is suggested to use ω-polymerization of vinyl monomers for preparation of functionalized nanoporous polymer composites for different .technical and biomedical applications.     

Synthesis of 2-Arylbenzofuran: Confirmation of the Structure of Gnetifolin A

GnethelinAu'asisolatedfromGnetumparvghlium(Warb.)C.Y.Chengb}'Lietal.'ItSstructUrextasproPosedpre\'iousl}'as2-(3.5allhydroxT4-methomphen}l)-3-methony-5-hydrox3-benLzofiiran(l).Aner9'nthesisofset1eralanalogsofStrUctUre(l),theStrUCtUrofGnetjfolinAseemstobenustakenanduasrerisedas2K3-5allhydrOny4-methomphenyl)4-methoxy-5-hvdrowtenzofuran(2).=Inordertoconfirmthisrer4ndmCtUranddevelopaversahlewtehcrouteforthe9-nthesisofGnetjfolinAandanalogs,2T-edSyl4-methoxy-5-hydrotwllZofuran(3)u'asselec…     

Study of the system Pr2O3-SeO2-H2O at 100°C and the properties of the compounds obtained

The solubility of the system Pr₂O₃-SeO₂-H₂O at 100°C was studied. The fields of crystallization of Pr₂(SeO₃)₃·H₂O, PrH(SeO₃)₂, Pr(HSeO₃)₃ were established. The compounds obtained were identified by means of chemical, X-ray and thermal analysis. The thermal decomposition of Pr₂(SeO₃)₃·H₂O, PrH(SeO₃)₂, and Pr(HSeO₃)₃ was determined.This revised version was published online in November 2005 with corrections to the Cover Date.     

Study on the Synthesis of Metabolite CM2 of Clausenamide

Synthesis of the optically active metabolite of clausenamide cm2(3,5-dihydroxy-5-(α-hydroxylbenzyl)-1-methyl-4-benzylpyrrolidin-2-one)from 3-O-acetyl-clausenamide was described.     

Study on the sulfinatodehalogenation of BrCF_2CF_2R

Sodium dithionite initiated sulfinatodehalogenation of BrCF2CF2R is studied.     

Refining the Phase Diagram of the System 3Al2O3·2SiO2-ZrO2

The quasi-binary section mullite-zirconium dioxide in the ternary system Al₂O₃-SiO₂-ZrO₂, described by an eutectic phase diagram with T _{e u t} = 1750°C, was studied experimentally.     

Synthesis ofβ-glycosides of n-acetylglucosamine in the presence of HgI2

The use of HgI₂ as catalyst in the synthesis oftrans-glycosides of N-acetylglucosamine is described. Using this catalyst, -glycosides of N-acetylglucosamine with aglycons of different structures and lyophilicities have been synthesized. The possibility of performing oligosaccharide synthesis has been demonstrated.     

Intracavity laser spectroscopy of the HfCl molecule. Analysis of rotational structure of new bands of the 2Δ-X2Δ electronic transition

Electron absorption spectrum of the HfCl molecule was studied in the 550–800 nm region using intracavity laser spectroscopy. HfCl molecules were obtained using the passage of an impulse electric discharge through a mixture of HfCl₄ and He vapors. A cuvette with the mixture of gases was placed in a dyelaser resonator cavity. The spectra were registered using diffraction spectrograph (resolution capability 240000). The high sensitivity of the intracavity method made it possible to detect in the HfCl spectrum new bands with a resolved rotational structure. Rotational analyses of the given bands were performed and the molecular constants were determined.     

Hygrometric Determination of the Water Activities of the Aqueous Solutions of the Mixed Electrolyte NaCl–CaCl2–H2O at 25°C

The mixture {yNaCl + (1 – y)CaCl₂}(aq) has been studied with the hygrometric method at the temperature 25°C. The water activities were measured at total molalities from 0.25 mol-kg^–1 to near saturation for different ionic-strength fractions y of NaCl with y = 0.33, 0.50, and 0.67. The obtained data allow the calculation of osmotic coefficients. The experimental results are compared with the predictions of the Zdanovskii–Stokes–Robinson (ZSR), Kusik and Meissner (KM), Robinson and Stokes (RS), Lietzke and Stoughton (LS II), Reilly–Wood–Robinson (RWR), and Pitzer models. From the measured osmotic coefficients, the Pitzer ionic mixing parameters _{Na Ca} and _{Na Ca} Cl are determined and are used to predict the solute activity coefficients in the mixtures. The excess Gibbs energy is also determined. These results are compared with those given in the literature.