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Showing papers in "Chinese Journal of Chemistry in 2010"


Journal ArticleDOI
TL;DR: The conformations of some cycloadducts and cycloaddition mechanism are described in this paper, where the synthesis of tricyclic heterocyclic compounds has been studied.
Abstract: Benzodiazepine and benzothiazepine derivatives have been well known as therapeutically important compounds. Four new tricyclic heterocyclic compounds, 3a, 4, 5, 11-tetrahydro-3H-l,2, 4-triazalo [4, 3-d] [1, 5] benzothiazepines (3), 3a, 4, 5, 11-tetrahydro-3H,6H-1, 2, 4-triazolo[4, 3-d] [1, 5]benzodiazepine (4), 3a, 4, 5, 11-tetrahydro-1, 2, 4-oxadiazolo [4, 5-d] [1, 5]benzothiazepines (5, 6) and 3a,4, 5, 11-tetrahydro-6H-1, 2, 4-oxadiazolo[4, 5-d] [1, 5] benzodiazepines (7, 8), have been synthesized by 1, 3-dipolar cycloaddition reactions of 2, 3-dihydro-1, 5-benzothiazepines and 2, 3-dihydro-1H-1, 5-benzodiazepine with benzonitrile N-phenylimine and benzonitrile oxides, receptively. The conformations of some cycloadducts and cycloaddition mechanism are described.

75 citations


Journal ArticleDOI
Kangyu Chen1, Yuan Guo1, Zhenhuan Lu1, Bingqin Yang1, Zhen Shi1 
TL;DR: Four coumarin-based fluorescent probes with salicylaldehyde functionality as recognition unit have been developed for selective detection of bisulfite anions in water.
Abstract: Coumarins and its analogues have been widely used as chromophore in design of fluorescent probe, while less coumarin-based fluorescent probe was reported for detection of anion in water. In this article, coumarin-based fluorescent probes with salicylaldehyde functionality as recognition unit have been developed for selective detection of bisulfite anions in water. Four novel fluorescent probes were synthesized from 4-haloresorcinol in three steps. The chemoprobe exhibited selective response to bisulfite over other anions. Moreover, the detection mechanism was studied. Upon bisulfite added, the fluorescent intensity of the probes was enhanced highly due to the nucleophilic addition reaction of formyl group with bisulfite anion.

70 citations


Journal ArticleDOI
TL;DR: In this article, the formation of calcium carbonate was controlled by extracellular polymeric substances (EPS) isolated from Bacillus pasteurii, and the results showed that the compressive strength of recovered specimens was restored to 84%, which demonstrated that this kind of bio-restoration method is effective in repairing surface defects of cement-based materials.
Abstract: Bacterial induced carbonate mineralization has been demonstrated as a new potential method for restoration of limestones in historic buildings and monuments. We claim here the formation of calcium carbonate was controlled by extracellular polymeric substances (EPS) isolated from Bacillus pasteurii. The process of crystallization nucleation was accelerated in the presence of cells and inhibited in the presence of EPS. The CaCO3 film deposited on cement paste surface was about 100 μm after 7 d treatment. The results of various restoring methods showed that higher decrease of water absorption of cement paste was gained in brushing application in the presence of agar, which could maintain urease with high activity in long term compared to spraying method. The coefficient of capillary suction of cement paste treated with brushing method was reduced by 90%. Mixed media consisted of sands, urea, Ca2+ and concentrated biomass, was injected into artificial cracks of cement paste followed by continual nutrient supplement, and CaCO3 particles were precipitated gradually between sands particles which were combined with cement matrix. The results showed that the compressive strength of recovered specimens was restored to 84%, which demonstrated that this kind of bio-restoration method is effective in repairing surface defects of cement-based materials.

62 citations


Journal ArticleDOI
TL;DR: The results suggested that the immunoactive components of the fruit of Lycium barbarum L. could enhance the splenocyte proliferation in normal mice and the effects of glycan chain were stronger than those of glycoconjugate.
Abstract: The detailed structure of an O-glycan derived from the fruit of Lycium barbarum L. was elucidated based on glycosidic linkage analysis, complete and partial acid hydrolysis, 1H-NMR and 13C NMR spectroscopy. According to the experiments, the carbohydrate was in the form of polysacchride (arabinogalactan) chains with highly branched 3, 4-galactans and terminal arabinofuranosyl substituents. The immuno-modulating mechanism of glycoconjugate and its glycan were investigated using tritium thymidine incorporation assay, flow cytometry assay and electrophoretical mobility shift assay (EMSA). The results suggested that the immunoactive components of the fruit of Lycium barbarum L. could enhance the splenocyte proliferation in normal mice and the effects of glycan chain were stronger than those of glycoconjugate. The target cell was most likely to be B-lymphocyte, on which existed receptor binding site acting with the glycan. In addition, the immuno-stimulatory effect of glycoconjugate (LbGp4) and its glycan (LbGp4-OL) was associated with activating the expression of nuclear factor KB (NF-KB) and activator protein 1 (AP-1).

59 citations


Journal ArticleDOI
TL;DR: W-Mn/SiO2 catalyst has been developed in this paper, which is active, selective and stable for oxidative coupling of methane (OCM) in fixed bed and fluidized bed reactors.
Abstract: W-Mn/SiO2 catalyst has been developed in our laboratory (LICP), which is active, selective and stable for oxidative coupling of methane (OCM) in fixed bed and fluidized bed reactors. The research results have been reproduced at different reaction conditions by two groups of J. H. Lunsford (JH-LL) from Texas A & M University and R. M. Lambert (RMLL) from University of Cambridge respectively. The basic research aspects on this catalyst systems, reaction performances, structure characterization and reaction mechanism were reviewed. A model on two active sites related to W6+/5+ and Mn3+/2+ has been suggested for activation of methane and oxygen respectively.

52 citations


Journal ArticleDOI
TL;DR: In this article, the feasibility of photocatalytic reduction of nitrobenzene using titanium dioxide powder as photocatalyst, under the protection of nitrogen and presence of hole scavenger conditions, was studied.
Abstract: The feasibility of photocatalytic reduction of nitrobenzene using titanium dioxide powder as photocatalyst, under the protection of nitrogen and presence of hole scavenger conditions, was studied. Effects of the illumination time, amount of catalyst and sorts of solvent on the photocatalytic reduction of nitrobenzene were investigated, respectively. The results showed that, for the photocatalytic reduction of nitrobenzene, aniline was the main product. When the illumination time was 6 h, 8.15×10−4 mol/L of nitrobenzene could be photocatalytically reduced completely, with the yield of aniline being 88.5%. The optimum amount of TiO2 used was 4.0 g/L, the optimum initial pH value of reaction solution was 4.0 and the best solvent was methanol. The kinetics and mechanisms of the photocatalytic reduction of nitrobenzene were also discussed.

51 citations


Journal ArticleDOI
TL;DR: In this paper, the reaction of 5-benzodiazepines with dichlorocarbene generated in situ using benzyltriethylammonium chloride (TEBA) as a phase transfer catalyst in chloroform-aqueous sodium hydroxide mixture gave mainly 1,2-cycloadducts, cis and trans-1a, 3-disubstituted-1, 1-dichloro-4-formyl-1α, 2,3,4-tetrahydro-1H-azirino
Abstract: Reaction of 2, 3-dihydro-1H-1. 5-benzodiazepines with dichlorocarbene generated in situ using benzyltriethylammonium chloride (TEBA) as a phase transfer catalyst in chloroform-aqueous sodium hydroxide mixture gave mainly 1,2-cycloadducts, cis and trans-1a, 3-disubstituted-1, 1-dichloro-1a, 2,3,4-tetrahydro-1H-azirino[1,2-a][1,5]benzodiazepines (2.3), and formylated 1,2-cycloadducts, trans-1a,3-disubstituted-1, 1-dichloro-4-formyl-1a, 2, 3, 4–1 H-azirino[1, 2-a][1, 5]benzodiacepines (4). The stereo-structures of cycloadducts and the mechanism are also discussed.

47 citations


Journal ArticleDOI
TL;DR: In this paper, the structures of the products were determined by single crystal X-ray diffraction analysis, and they were shown to be acridine derivatives of α-cyanocinnamonitrile and β-cyano-β-carbothoxy styrene.
Abstract: In the reactions of α-cyanocinnamonitrile or β-cyano-β-carbothoxy styrene with 5,5-dimethyl-1,3-cyclohexanedione in the presence of ammonium acetate under microwave irradiation without solvent, the 2-amino-5,6,7,8-tetrahydro-5-oxo-4-aryl-7,7-dimethyl-4H-benzo-[b]-pyran derivatives were obtained. However, in the reactions of arylidenecyanoacetamide with 5,5-dimethyl-l,3-cyclohexanedione under the same reaction conditions, the acridine derivatives were obtained. The structures of the products were determined by single crystal X-ray diffraction analysis.

45 citations


Journal ArticleDOI
TL;DR: In this paper, the performance of Nafion and SPSF membranes in ammonia synthesis was investigated and compared at atmospheric pressure and low temperature (25-100°C). And the results demonstrated that the proton conducting performances of both polysulfone (PSF) and sPSF membrane were similar and the highest rates of evolution of ammonia were up to 1.03×10−8 mol·cm−2·s−1 respectively at 80°C and 2.5 V.
Abstract: Polysulfone (PSF) and sulfonated polysulfone (SPSF) were synthesized and characterized by IR spectrum. Sm1.5Sr0.5NiO4 (SSN) and Ni-Ce0.8Sm0.2O2−δ (Ni-SDC, Ni-samarium doped ceria) were prepared and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Ammonia was synthesized from wet hydrogen and dry nitrogen with applied voltage, using SSN as cathode, Ni-SDC as anode, Nafion and SPSF as proton membrane respectively. The performances of Nafion and SPSF membranes in ammonia synthesis were investigated and compared at atmospheric pressure and low temperature (25–100°C). The results demonstrated that the proton conducting performances of Nafion and SPSF membranes were similar and the highest rates of evolution of ammonia were up to 1.05×10−8 and 1.03×10−8 mol·cm−2·s−1 respectively at 80°C and 2.5 V.

45 citations


Journal ArticleDOI
TL;DR: In this paper, micro-capsules containing phase change material, n-eicosane, were synthesized by using interfacial polymerization method with toluene-2,4-diisocyanate (tdi) and diethylenetriamine (deta) as monomers in an emulsion system.
Abstract: For heat energy storage application, polyurea. microcapsules containing phase change material, n-eicosane, were synthesized by using interfacial polymerization method with toluene- 2,4-diisocyanate (tdi) and diethylenetriamine (deta) as monomers in an emulsion system. poly(ethylene glycol)octyl-phenyl ether (op), a nonionic surfactant, was the emulsifier for the system. the experimental result indicates that tdi was reacted with deta in a mass ratio of 3 to 1. ft-ir spectra confirm the formation of wall material, polyurea, from the two monomers, tdi and deta. encapsulation efficiency of n-eicosane is about 75%. microcapsule of n-eicosane melts at a temperature close to that of n-eicosane, while its stored heat energy varies with core material n-eicosane when wall material fixed. thermo-gravimetric analysis shows that core material n-eicosane, micro-n-eicosane and wall material polyurea can withstand temperatures up to 130, 170 and 250 degreesc, respectively.

44 citations


Journal ArticleDOI
Abstract: 4-Aryl-3, 4-dihydropyrimidinones were synthesized using microwave-assisted, solvent-free protocol of the Biginelli reaction. The simple method provides the title compounds in 78%-95% yields by the reaction of aromatic aldehydes with ethyl acetoacetate and urea/thiourea in the presence of a catalytic amount of conc. HCl. Lewis acids, such as ZnCl2, SnCl2, FeCl3·6H2O, and CuCl2·2H2O, were also found to be efficient catalysts for the synthesis of dihydropyrimidinones.

Journal ArticleDOI
TL;DR: An efficient and convenient preparation of fullerenols was described, with polyethylene glycol (PEG) 400 as catalyst, and by control of reaction conditions, either water-soluble C, fulleRenol or water-insoluble C60 fulle Renol could be obtained selectively.
Abstract: An efficient and convenient preparation of fullerenols was described. With polyethylene glycol (PEG) 400 as catalyst, fullerenols were conveniently synthesized via the direct reaction of fullerene with aqueous NaOH. By control of reaction conditions, either water-soluble C, fullerenol or water-insoluble C60 fullerenol could be obtained selectively.

Journal ArticleDOI
Yi Zhang1, Zuohu Li1, Tao Qi1, Zhi-Kuan Wang1, Shili Zheng1 
TL;DR: In this paper, a green chemical process of the heterogeneous reaction and separation system of liquid phase oxidation of chromite in molten salt of sodium hydroxide-one way separation in high concentration medium-metastable phase separation-carbonate recycle conversion has been developed.
Abstract: Research topics and methods of green chemistry in chromate production are introduced in this paper. New original green chemical process of the heterogeneous reaction and separation system of liquid phase oxidation of chromite in molten salt of sodium hydroxide-one way separation in high concentration medium-metastable phase separation-carbonate recycle conversion has been developed. The green commercial process for comprehensive utilization of mineral resources-reactant recycle inside the process-zero emission was established.

Journal ArticleDOI
TL;DR: Two new flavonoids, acanthophorin A and A and B, along with three known compounds tiliroside, (-)-catechin and quercetin were isolated from the red alga Acanthophora spicifera and showed significant antioxidant activity.
Abstract: Two new flavonoids, acanthophorin A (1) and acanthophorin B (2), along with three known compounds tiliroside (3), (-)-catechin (4) and quercetin (5) were isolated from the red alga Acanthophora spicifera. The structures of 1 and 2 were determined to be kaempferol 3-O-α-L-fucopyranoside (1) and quercetin 3-O-α-L-fucopyranoside (2) by spectroscopic methods. Both 1 and 2 showed significant antioxidant activity.

Journal ArticleDOI
Aly A. Aly1
TL;DR: Quinazoline isothiocyanate 1 reacts with various nucleophiles to afford heterocyclic systemes 2, 3, 4, 5, 6, 7, 8 and 9 as discussed by the authors.
Abstract: Quinazoline isothiocyanate 1 reacts with various nucleophiles (nitrogen nucleophiles, oxygen nucleophiles and sulphur nucleophiles) to afford heterocyclic systemes 2–13. Also, the [4 + 2] cycloaddition reaction of 1 with phenyl isocyanate, benzylidene aryl amine and cinnamic acid derivatives gave novel heterocyclic compounds 14–16. Moreover, the reaction of 1 with active methylene compounds under Michael reaction conditions also was investigated to yield 17 and 18 and it was found that all these reactions proceeded via isothiocyanate heterocyclization to furnish non-condensed heterocyclic compounds. Some of the newly synthesized compounds were tested for their antimicrobial activities.

Journal ArticleDOI
TL;DR: A glycoconjugate designated as LbGp5B was isolated from the fruit of Lycium barbarian L. and purified to homogeneity by gel filtration as discussed by the authors.
Abstract: A glycoconjugate designated as LbGp5B was isolated from the fruit of Lycium barbarian L. and purified to homogeneity by gel filtration. LbGpSB is composed of rhamnose (Una), arabinose (Ara), galactose (Gal), glucose (Glc), galacturonic add (GalA) and seventeen amino adds. The molecular weight of LbGpSB was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and by matrix-assisted laser desorption/ionization (MALDI) time of fight (TOF) mass spectrometry (MS). The preliminary experiments showed that LbGpSB promoted splenocyte proliferation in mice and inhibited the peroxidation of low density lipoprotein (LDL).

Journal ArticleDOI
TL;DR: In this paper, the ion exchange characteristics of Amberlite IRA 743 resin for extracting boron from aqueous fluids have been investigated in detail, and it was shown that the maximum volume of loaded solution giving quantitative extraction of B(OH)−4 species from weakly basic solution must be restricted.
Abstract: The ion exchange characteristics of Amberlite IRA 743 resin for extracting boron from aqueous fluids have been investigated in detail. The results show that Amberlite IRA 743 resin, a boron-specific ion exchange resin, can quantitatively extract boron as the B(OH)−4 species from weakly basic solution. Some exchangeable anions such as Cl−and SO24 are present, resulting in an increase in pH value of the loaded solution within the column, and the boron in natural aqueous fluids with low pH is also extracted by Amberlite IRA 743 resin. However, the volume of loaded solution must be restricted. The maximum volume of loaded solution giving quantitative extraction of boron decreases for sample solutions of lower pH value. Warm HG solution is more effective than room temperature HC1 solution for eluting boron from Amberlite IRA 743 resin.

Journal ArticleDOI
TL;DR: In this paper, an asymmetric Mannich-type reaction of hydrazone 1a with difluoroenoxysilane 2 using chiral phosphine-oxazoline ligand has been reported, giving the adduct 3a in good yields and moderate enantioselectivities under mild conditions.
Abstract: With the catalysis of Zn(OTf)2, Mannich-type reactions of various aromatic hydrazones 1 with difluoroenoxysilane 2 proceeded smoothly to produce 2,2-difluoro-3-oxo-benzohydrazides in 27% –78% yields in THF or DCM under mild conditions. An unexpected monofluorination of hydrazone 1m with difluoroenoxysilane 2 was also disclosed in this paper. The first example of the asymmetric Mannich-type reaction of hydrazone 1a with difluoroenoxysilane 2 using chiral phosphine-oxazoline ligand has been reported, giving the adduct 3a in good yields and moderate enantioselectivities under mild conditions.

Journal ArticleDOI
TL;DR: In this article, an improved procedure for extraction and purification of boron from natural samples is presented, which is carried out using a borón-specific resin, Amberlite IRA743, and a mixed ion exchange resin, Dowex 50W × 8 and Ion Exchanger II resin.
Abstract: An improved procedure for extraction and purification of boron from natural samples is presented. The separation and purification of boron was carried out using a boron-specific resin, Amberlite IRA743, and a mixed ion exchange resin, Dowex 50W × 8 and Ion Exchanger II resin. Using the mixed ion exchange resin which adsorbs all cations and anions except boron, the HCl and other cations and anions left in eluant from the Amberlite IRA 743 were removed effectively. In this case, boron loss can be avoided because the boron-bearing solution does not have to be evaporated to reach dryness to dislodge HCl. The boron recovery ranged from 97.6% to 102% in this study. The isotopic fractionation of boron can be negligible within the precision of the isotopic measurement. The results show that boron separation for the isotopic measurement by using both Amberlite IRA 743 resin and the mixed resin is more effective than that using Amberlite IRA 743 resin alone. The boron in samples of brine, seawater, rock, coral and foraminifer were separated by this procedure. Boron isotopic compositions of these samples were measured by thermal ionization mass spectrometry in this study.

Journal ArticleDOI
TL;DR: In this article, the saturated tricarboxylic acids were obtained in good yields in an undivided cell with Ni cathode and Al sacrificial anode containing n-Bu4NBr-DMF as supporting electrolyte.
Abstract: With some common metal salts (CuI, FeCl3) as catalysts, alkynes can be effectively electrocarboxylated with CO2 (4 MPa) in an undivided cell with Ni cathode and Al sacrificial anode containing n-Bu4NBr-DMF as supporting electrolyte with a constant current at room temperature. The saturated tricarboxylic acids besides the dicarboxylic acids were obtained in good yields. The yields of the tricarboxylic acids were strongly influenced by various metal salt catalysts, cathode materials and the property of substituted groups. Finally, the possible electrochemical mechanism was discussed.

Journal ArticleDOI
Xu Jin-Zhong1, Zhu Jun-Jie1, Wu Qiang1, Hu Zheng1, Chen Hong-Yuan1 
TL;DR: In this article, the direct electrochemical behavior between the glucose oxidase (GOD) and the multi-walled carbon nanotubes (MWNTs) has been studied, and two pairs of cyclic voltammetric peaks corresponding to the two different processes, i.e., mass-transport and surface reaction of GOD are observed on this MWNTs.
Abstract: The direct electrochemical behavior between the glucose oxidase (GOD) and the multi-walled carbon nanotubes (MWNTs) has been studied. Two pairs of cyclic voltammetric peaks corresponding to the two different processes, i.e. mass-transport and surface reaction of GOD are observed on this MWNTs. The formal potentials with Eo' =-0.45 V and Eo' =-0.55 V were obtained respectively. The GOD film was observed on the carbon nanotube by the TEM.

Journal ArticleDOI
TL;DR: In this paper, two stilbenoids, cis-ϵ-viniferin (3) and 2b, 14b-dehydro-bisresveratrol (4) were synthesized by photooxidation reaction of trans- ϵ-viferin prepared from tram-reserveratrol, and their structures were elucidated on the basis of spectral evidence.
Abstract: Two new stilbenoids, cis-ϵ-viniferin (3) and 2b, 14b-dehydro-bisresveratrol (4) were synthesized by photooxidation reaction of trans-ϵ-viniferin (2) prepared from tram-resveratrol (1). Pentamethoxyl trans-ϵ-viniferin (5) and pentamethoxyl cis-ϵ-viniferin (6) were also obtained by methylation of trans-ϵ-viniferin (2) with (MeO)2SO2. Their structures were elucidated on the basis of spectral evidence. Compounds 3 and 4 showed potent inhibition of TNF-α at concentrations of 10−-5 mol.L−1 with inhibitory ratios of 51.43% and 36.64%. respectively.

Journal ArticleDOI
TL;DR: In this article, resorcinarene-functionalized gold nanoparticles (AuNPs) were prepared conveniently in aqueous solution in the presence of amphiphilic tetramethoxyresorcinarane tetraaminoamide, and the obtained AuNPs were characterized and analyzed by UV-vis, FT-IR, XRD and TEM.
Abstract: Resorcinarene-functionalized gold nanoparticles (AuNPs) were prepared conveniently in aqueous solution in the presence of amphiphilic tetramethoxyresorcinarene tetraaminoamide. The obtained AuNPs were characterized and analyzed by UV-vis, FT-IR, XRD and TEM, respectively. The results showed that the size of AuNPs and the standard deviations were all decreasing with the increase of resorcinarene concentration. In addition, the catalytic activity of the obtained AuNPs in the reduction of aromatic nitro compounds was also investigated. In aqueous solution the reaction follows a first order kinetics and the size of AuNPs has influence on the rate of reduction.

Journal ArticleDOI
TL;DR: The crystal and molecular structure of [Pd(iPr2dtc)2] (dtc = dithiocarbamate) have been determined by X-ray crystallography as mentioned in this paper.
Abstract: The crystal and molecular structure of [Pd(iPr2dtc)2] (dtc = dithiocarbamate) have been determined by X-ray crystallography. The unit cell of the crystal structure consists of two discrete monomelic molecules of [Pd(iPr2dtc)2]. The Pd(II) ion has an square-planar geometry. The electronic and IR spectral data are in agreement with the X-ray structure. The TG data indicate slight degradation of a few percent.

Journal ArticleDOI
TL;DR: In this paper, the presence of carbon, silicon, sulfur and nitrogen in rice husk ash (RHA) and 3-(mercaptopropyl)-trimethoxysilane (MPTMS) was determined by a combination of elemental analysis and EDX study.
Abstract: Sodium silicate from rice husk ash (RHA) was transformed to functionalized silica with 3-(mercaptopropyl)-trimethoxysilane (MPTMS) or 3-(aminopropyl)triethoxysilane (APTES) via a simple sol-gel technique in a one-pot synthesis to give RHAPrSH and RHAPrNH2. The 29Si MAS NMR of RHAPrSH and RHAPrNH2 showed the presence of T1, T2, T3, Q2, Q3 and Q4 silicon centers. The 13C MAS NMR showed that RHAPrSH had chemical shifts at δ 16.59, 32.73, consistent with two of the carbon atoms of the MPTMS moiety, while the 13C MAS NMR of RHAPrNH2 had chemical shifts at δ 14.58, 26.13, 47.87, consistent with the three carbon atoms of the APTES moiety. The presence of carbon, silicon, sulfur and nitrogen in RHAPrSH and RHAPrNH2 was determined by a combination of elemental analysis and EDX study.

Journal ArticleDOI
TL;DR: In this article, a new method for the separation of nucleotides is developed and the essential feature of the method is that 1-alkyl-3-methylimidazolium salts are used as mobile phase additives, resulting in a baseline separation without need of gradient elution and need of organic solvent addition as currently used in RP-HPLC.
Abstract: Ionic liquids are a type of salts that are liquid at low temperature (<100 °C). Because of their some special properties, they have been widely used as new “green solvents” for many chemical reactions and liquid-liquid extraction in the past several years. In this paper, a new method for the separation of nucleotides is developed and the essential feature of the method is that 1-alkyl-3-methylimidazolium salts are used as mobile phase additives, resulting in a baseline separation of nucleotides without need of gradient elution and need of organic solvent addition as currently used in RP-HPLC. This study shows the potential application of ionic liquids as mobile phase additives in reversed-phase liquid chromatography.

Journal ArticleDOI
Xianxi Zhang1, Meng Bao1, Na Pan1, Yuexing Zhang1, Jianzhuang Jiang1 
TL;DR: In this paper, a density functional B3LYP-based analysis of the vibrational frequencies and intensities of metal-free phthalocyanine (H2Pc) analogues and their metal complexes is presented.
Abstract: Vibrational (IR and Raman) spectra for the metal-free phthalocyanine (H2Pc) have been comparatively investigated through experimental and theoretical methods. The frequencies and intensities were calculated at density functional B3LYP level using the 6-31G(d) basis set. The calculated vibrational frequencies were scaled by the factor 0.9613 and compared with the experimental result. In the IR spectrum, the characteristic IR band at 1008 cm−1 is interpreted as C—N (pyrrole) in-plane bending vibration, in contrast with the traditional assigned N—H in-plane or out-of-plane bending vibration. The band at 874 cm−1 is attributed to the isoindole deformation and aza vibration. In the Raman spectrum, the bands at 540. 566, 1310, 1340, 1425, 1448 and 1618 cm−1 are also re-interpreted. Assignments of vibrational bands in the IR and Raman spectra are given based on density functional calculations for the first time. The present work provides valuable information to the traditional empirical assignment and will be helpful for further investigation of the vibration spectra of phthalocyanine analogues and their metal complexes.

Journal ArticleDOI
Jianfeng Guo1, Jingxia Li1, Anyuan Yin1, Kangnian Fan1, Wei-Lin Dai1 
TL;DR: Sulfur doped ZnO/TiO2 nanocomposite photocatalysts were synthesized by a facile sol-gel method as discussed by the authors by using X-ray diffraction (XRD), XPS, and UV-vis diffusive reflectance spectroscopy (DRS).
Abstract: Sulfur doped ZnO/TiO2 nanocomposite photocatalysts were synthesized by a facile sol-gel method The structure and properties of catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-vis diffusive reflectance spectroscopy (DRS) and N2 desorption-adsorption isotherm The XRD study showed that TiO2 was anatase phase and there was no obvious difference in crystal composition of various S-ZnO/TiO2 The XPS study showed that the Zn element exists as ZnO and S atoms form SO2−4 The prepared samples had mesoporosity revealed by N2 desorption-adsorption isotherm result The degradation of Rhodamine B dye under visible light irradiation was chosen as probe reaction to evaluate the photocatalytic activity of the ZnO/TiO2 nanocomposite The commercial TiO2 photocatalyst (Degussa P25) was taken as standard photocatalyst to contrast the prepared different photocatalyst in current work The improvement of the photocatalytic activity of S-ZnO/TiO2 composite photocatalyst can be attributed to the suitable energetic positions between ZnO and TiO2, the acidity site caused by sulfur doping and the enlargement of the specific area S-30ZnO/TiO2 exhibited the highest photocatalytic activity under visible light irradiation after Zn amount was optimized, which was 26 times higher than P25

Journal ArticleDOI
TL;DR: In this paper, a triclinic trifluoroacetone monoanion was synthesized in mixed solvents of acetone and ethanol (1:1 volume ratio) and its crystal structure has been determined by X-ray diffraction.
Abstract: The title complex Eu(III)(TTA)3(phen) (where TTA = thenoyltrifluoroacetone monoanion; phen = 1,10-phenanthroline) has been synthesized in mixed solvents of acetone and ethanol (1:1 volume ratio) and its crystal structure has been determined by X-ray diffraction. The complex crystals are triclinic, space group P 1 (# 2) with cell dimensions of a = 1.32.41 (2) nm, b = 1.5278(4) nm, c = 0.9755(3) nm, α = 92.49 (2)°, β = 102.57(2)°, γ = 91.62(2)°, V = 1.9268(8) nm3, Z = 2, μ (Mo Ka)= 18.77 cm−1, Dx=1.720 g/cm3. The coordination geometry of Eu atom is a distorted square antiprism, and the encapsulated structure that can meet the structural requirement of the typical europium luminescent sensor. The fluorescence spectrum suggests that the complex is a strong photoluminescent material.

Journal ArticleDOI
TL;DR: In this paper, a new method of investigating the kinetic parameters and mechanism functions of a solid phase reaction is presented, based on the use of these data at the same temperature and the same degree of conversion on a series of TA curves with different heating rates, so that the kinetic triplet-the activation energy E, the preexponential factor A and the analytical form of the function of conversion f (α) can be obtained.
Abstract: A new method of investigating the kinetic parameters and mechanism functions of a solid phase reaction is presented. This method is to analyze the data based on the use of these data at the same temperature and the same degree of conversion on a series of TA curves with different heating rates, so that the kinetic triplet–-the activation energy E, the pre-exponential factor A and the analytical form of the function of conversion f (α) can be obtained. The main advantage of this method is that the values of E and f(α) are obtained respectively, and the determination of f (α) is not under the influence of the value of E and the calculation of the value of E is not influenced by the f (α) either.