Study on the sulfinatodehalogenation of BrCF_2CF_2R

Sodium dithionite initiated sulfinatodehalogenation of BrCF2CF2R is studied.     

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.     

Effect of CuO Doping on the Electrical Behavior of ZrO2

Electrical conductivity has been measured at different temperatures for ZrO2 doped with various molar ratios of CuO. The conductivity increases due to migration of vacancies, created by doping. The conductivity was found to increase with increase in temperature till 220℃ and thereafter decrease due to collapse of the fluorite framework. A second rise in conductivity around 500 ℃ was observed due to phase transition of ZrO2. X-ray powder diffraction, DTA and IR studies were carried out for confirming doping effect and phase transition in ZrO2.     

Heterogeneous reaction of NO_2 on the surface of NaCl particles

Sodium chloride is the major constituent of sea salt particles in atmospheric environment, with an esti- mated annual contribution of 1012 kg of sea salt parti- cles to the atmosphere[1]. Many studies have shown a significant chloride deficit in these particles when compared to bulk seawater[2,3]. This deficit has been attributed to reactions with NOx and SO2[4]. Simulta- neously, NO2 is one of the main pollutants of mobile vehicles. Reaction (1) may be particularly important to the atmosph…     

Effects of ZrO_2 on the Microstructure of a Mica Glass-ceramic

1 INTRODUCTION Glass-ceramic technology is based on the controlled nucleation and crystallization of glass, and glass-ceramics have several advantages over the conventional powder-processed ceramics. In addition to the easy flexibility of formation in t…     

The study on the effect of the substitution of K2CO3 with Ca(OH)2 on kinetics on CO2–lignite coal gasification

Research on Chemical Intermediates - Three kinds of lignite were mixed with K2CO3 and Ca(OH)2 and were gasified with CO2 to investigate the effect that the addition of Ca(OH)2 had on the...     

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.     

Influences of different cobalt sources on the properties of synthesized LiCoO_2

Since 1991, LiCoO2 used as cathode material of lithium-ion rechargeable batteries has attracted much attention in the industry of portable power apparatus such as mobiles, laptops and camcorders, etc. However, the production technologies of LiCoO2 have always been possessed by the foreign corporations. Although a plenty of research work has been performed in domestics, it is almost impossible to surpass the technological rampart, which renders our state to subject to much foreign exchange co…     

TEM Study on the Formation Process of TiO2 Nanotubes

The process,that the polycrystalline TiO2 powders were converted into TiO2 nanotubes,was observed with transmission electron microscope.The results obtained indicated that in concentrated NaOH aqueous solution,anisotroplc swelling appears on the polycrystalline TiO2 granula at first,and then the nanotubes are formed.     

Addition of γ-silyloxyallyltins on ethyl glyoxylate: evaluation of the influence of the experimental conditions on the stereochemical course of the reaction

Ethyl glyoxylate was reacted with α-substituted γ-(t-butyldimethylsilyloxy)-allyltributyltin in order to obtain selectively each diastereomer of ethyl 3-(t-butyldimethylsilyloxy)-2-hydroxyhex-4-enoate and subsequently the corresponding diols. Diastereomers syn-E, anti-E and anti-Z were obtained in good yields with good to high selectivities and the obtained results were rationalized by consideration of cyclic or open transition states in agreement with the experimental conditions and with the structure of the starting reagents.     

Effect of Dissolved CO_2 and Tetrahydrofuran on the Polymerization of Acrylic Acid

Recently,c0mpressedgaseshavebeenusedins0megasantisolventprocesses,suchasfractionati0n0fnaturaIproducts,recrystallization0forganicandin0rganicmaterials,andpolymerpr0cessing'2.WestudiedtheeffectofthedissovledsupercriticaICO=andTHFonthep0lymerizati0n0fAA.Itwasn0tfoundintheliterature.ExperimentalOnemlacrylicacidmonomer,O.O20ginitiator2,2'-azobis(is0butyronitrile)(AlBN),anddesiredam0unt0fTHFwereaddedintoanopticalcelloflOml.CO,wascharged,stirreduntilvap0r-liquidequilibriumwasreachedatabout30…     

A Study on the Effects of Carrier Gases on the Structure and Morphology of Carbon Nanotubes Prepared by Pyrolysis of Ferrocene and C2H2 Mixture

Carbon nanotubes （CNTs） were prepared using different carrier gases, with ferrocene as the catalyst precusor and acetylene as the carbon source. The effects of ammonia and nitrogen as carrier gases on the structure and morphology of CNTs were investigated. Transmission electron microscope （TEM）, high-resolution electron microscope （HRTEM）, scanning electron microscope （SEM） and X-ray diffraction （XRD） were employed to characterize the products and the catalyst. Experiment results show that the CNTs grown in N2 gas exhibited cylindrical and tubular structure, while a bamboo-like structure was observed for the CNTs grown in NH3 gas. Moreover, vertically aligned CNTs were obtained on an A12O3 disk when NH3 was used as the carrier gas. The carrier gas also exerted influence on the shape of the catalyst. Based on the theory of active centers of catalysis and combined with the particle shape of the catalyst, a growth model for the vertically aligned CNTs on the substrate is given.     

Effect of EtOH on the E-Iodohydroxylation of 1,2-Allenylic Sulfoxides with I_2

Allenes are a class of versatile compounds for or-ganic synthesis.1,2 Recently we have observed the highly selective E-iodohydroxylation of 1,2-allenylic sulfox-ides3,4 affording E-3-phenylsulfinyl-2-iodo-2-alkenols in high yields.5 The reaction of substituted 1,2-allenyl phenyl sulfoxides was usually carried out at r.t. while that of 1,2-propadienyl phenyl sulfoxide should be conducted at 55 ℃. In addition, it should be noted that the stereoselectivity of this reaction was determined by the…     

Study on the Formation Mechanism of Oxygen-containing Groups on the Surfaces of Hypercrosslinked Polystyrenes

Davankov and Tsyurupa described a new series of hypercrosslinked polymeric networks in 19691. Owing to their high internal surface area, unique porosity, and excellent swelling feature, hypercrosslinked polymers have exhibited a good adsorption affinity t…     

Studies on the Reaction Mechanism of Br2 ＋ I2 = 2IBr

1 INTRODUCTION Interhalogen compounds have played an impor- tant role in environment and chemical engineering production. During the course of ozone exhaustion induced by sunlight in polar region, Br2, BrCl and HOBr are all precursors of Br atom[1]. Lately, scien- tists have detected that the content of BrCl in polar region sunlight was 35 ppt, larger than that of Br2 (25 ppt). Previous studies suggested that the con- centration of BrCl and O3 exhibits obvious negative correlation: w…     

Effects of 2-hydroxypropyl α-cyclodextrin on the radioactive iodine sorption on activated carbon

Journal of Radioanalytical and Nuclear Chemistry - Effect of 2-hydroxypropyl α-cyclodextrin (α-HPCD) on the iodine adsorption onto activated carbon (AC) was investigated. The iodine...     

Theoretical study on the reaction mechanism of CH2SH + NO2

The mechanisms of CH₂SH with NO₂ reaction were investigated on the singlet and triplet potential energy surfaces (PES) at the BMC-CCSD//B3LYP/6-311 + G(d,p) level. The result shows that the title reaction is more favourable on the singlet PES thermodynamically, and it is less competitive on the triplet PES. On the singlet PES, the initial addition of CH₂SH with NO₂ leads to HSCH₂NO₂ (IM2) without any transition state, followed by a concerted step involving C–N fission and shift of H atom from S to O giving out CH₂S + trans-HONO, which is the major products of the title reaction. With higher barrier height, the minor products are CH₂S + HNO₂, formed by a similar concerted step from the initial adduct HSCH₂ONO (IM1). The direct abstraction route of H atom in SH group abstracted by O atom might be of some importance. It starts from the addition of the reactants to form a weak interaction molecular complex (MC3), subsequently, surmounts a low barrier height leading to another complex (MC2), which gives out CH₂S + trans-HONO finally. Other direct hydrogen abstraction channels could be negligible with higher barrier heights and less stable products.     

Effect of EtOH on the E-lodohydroxylation of 1,2-Allenylic Sulfoxides with l2

The E-iodohydroxylation of 1,2-allenylic sulfoxides with I2 in the presence of EtOH afforded 3-phenylsulfinyl-2-iodo-2(E)-alkenols in good yields and regio/stereo-selectivities under very mild conditions.     

Effects of synthesis parameters on the habit of CaO2 · 8H2O crystals

The Ca(OH)₂-H₂O₂-H₂O system at 0°C was studied using X-ray powder diffraction, thermo-gravimetry, and IR spectroscopy. Two solid phases were identified, namely CaO₂ · 8H₂O (I) and CaO₂ · 2H₂O₂ (II). The common concentration boundary of the crystallization fields of phase I and phase II was found to lie at 39 wt % H₂O₂. The existence of a solid phase of composition CaO₂ · 2H₂O (III), which had been discovered earlier by the solid residues method in an intermediate region between the fields of phase I and phase II, is not proven by the results of this study. The lower boundary of the crystallization field of phase I is drawn through a concentration less than 0.02 wt % H₂O₂, which differs from reported values (0.0 and 3.34 wt % H₂O₂). A solubility curve was constructed for phase I; the habit of isolated crystals and their sizes were studied as functions of synthesis parameters over a wide range of H₂O₂ concentrations. Crystals of I, which belong to the tetragonal crystal system, were observed in micrographs to be shaped as square and rectangular plates. Thin square plates preferred to precipitate near the lower concentration boundary, and thicker rectangular crystalline platelets (parallelepipeds), near the upper boundary.     

Studies on the Absorption of NO_2 by Polyethylene Glycol and the Oxidizing Properties of the Resulting Absorbent Product

NOxisoneoftheprimaryPOlluhonsourcesofatmSPhere.HowtodealwiththePOllutioncausedbyNo.isanimPqrtantsubjeCtonenvironmntalprotechon.Inourpreviousworks,wefoundTBP[l1wasabletoabsorbNO.(NoandNo2)efficientlyandtheallsothentprododwasusedtoconvertbemplalcoholstocorresPOndingaldehydsorketones.Inthiswork,theauthorsfindanotherorgboccompoUnd,PEG.canabsothNo2efficientiyandformanewcomPlex--PEG'No2.ThiscomplexcanbeusedasaInildandselechveokidanItocleavebenZyletherstobenzaldehydandcorreSPOndingfato'…