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2009 Volume 20 Issue 1
2009, 20(1): 1-4
doi: 10.1016/j.cclet.2008.10.022
Abstract:
Suzuki-Miyaura coupling reaction of N-protected 4-iodopheyl alanine isoxazoles with arylboronic acids, catalyzed by palladium, efficiently produce benzyl-N-(4-bipheyl)-2-(3-methyl-5(E)-2-aryl-1-ethenyl-4-isoxazolyl)-amino-2-oxoethyl) carba-mates in good yields. This process is first of its kind to construct carbon-carbon bond formation having biaryl motif on amino acid linked isoxazole moiety.
Suzuki-Miyaura coupling reaction of N-protected 4-iodopheyl alanine isoxazoles with arylboronic acids, catalyzed by palladium, efficiently produce benzyl-N-(4-bipheyl)-2-(3-methyl-5(E)-2-aryl-1-ethenyl-4-isoxazolyl)-amino-2-oxoethyl) carba-mates in good yields. This process is first of its kind to construct carbon-carbon bond formation having biaryl motif on amino acid linked isoxazole moiety.
2009, 20(1): 5-8
doi: 10.1016/j.cclet.2008.09.047
Abstract:
A new, convenient, efficient, and cost-effective one-pot synthesis of 1H-phenanthro[9,10]imidazol-2-yl from phenantherenquinone and aldehydes, using molecular iodine as catalyst is described. The present methodology offers several advantages such as excellent yields, simple procedure, shorter reaction times, and the use of inexpensive reagents.
A new, convenient, efficient, and cost-effective one-pot synthesis of 1H-phenanthro[9,10]imidazol-2-yl from phenantherenquinone and aldehydes, using molecular iodine as catalyst is described. The present methodology offers several advantages such as excellent yields, simple procedure, shorter reaction times, and the use of inexpensive reagents.
2009, 20(1): 9-12
doi: 10.1016/j.cclet.2008.10.018
Abstract:
This paper describes the facile synthesis and characterization of novel dendrimers bearing 9 and 12 CCK peptide fragments on the surface by a convergent method. The structures of dendrimers are characterized by NMR and MS spectrum.
This paper describes the facile synthesis and characterization of novel dendrimers bearing 9 and 12 CCK peptide fragments on the surface by a convergent method. The structures of dendrimers are characterized by NMR and MS spectrum.
2009, 20(1): 13-16
doi: 10.1016/j.cclet.2008.09.062
Abstract:
A novel fluorescent ionophore derived from calix[4]arene and pyrazoline was designed and synthesized. Its molecular structure was confirmed by 1H NMR and element analysis. The resulting material shows specific fluorescent behavior toward the Zn2+ ion among the other divalent metal ions, such as Co2+, Ni2+, Cu2+. The primary results indicate this ionophore material is a potential material for developing efficient fluorescent Zn2+ chemosensors.
A novel fluorescent ionophore derived from calix[4]arene and pyrazoline was designed and synthesized. Its molecular structure was confirmed by 1H NMR and element analysis. The resulting material shows specific fluorescent behavior toward the Zn2+ ion among the other divalent metal ions, such as Co2+, Ni2+, Cu2+. The primary results indicate this ionophore material is a potential material for developing efficient fluorescent Zn2+ chemosensors.
2009, 20(1): 17-20
doi: 10.1016/j.cclet.2008.10.017
Abstract:
The microwave-assisted coupling reaction of electrondeficient aryl halides with sulfinic acid salts through SNAr-based addition reactions within 5-30 min. No catalysts were required under our conditions.
The microwave-assisted coupling reaction of electrondeficient aryl halides with sulfinic acid salts through SNAr-based addition reactions within 5-30 min. No catalysts were required under our conditions.
2009, 20(1): 21-24
doi: 10.1016/j.cclet.2008.10.016
Abstract:
Chiral bis-corrole 1 and 2 were prepared by reaction of (s)-2,2'-bis(bromomethyl)-1,1'-binaphthyl and 10-(4-hydroxylphenyl)-5,15-bis(pentafluorophenyl)corrole or 10-(3-hydroxylphenyl)-5,15-bis(pentafluorophenyl)corrole in DMF at 60℃ in the presence of anhydrous K2CO3 with an isolated yield~8%. Both 1 and 2 exhibit unsymmetrical induced circular dichroism (ICD) in the soret band with positive exciton chirality.
Chiral bis-corrole 1 and 2 were prepared by reaction of (s)-2,2'-bis(bromomethyl)-1,1'-binaphthyl and 10-(4-hydroxylphenyl)-5,15-bis(pentafluorophenyl)corrole or 10-(3-hydroxylphenyl)-5,15-bis(pentafluorophenyl)corrole in DMF at 60℃ in the presence of anhydrous K2CO3 with an isolated yield~8%. Both 1 and 2 exhibit unsymmetrical induced circular dichroism (ICD) in the soret band with positive exciton chirality.
2009, 20(1): 25-28
doi: 10.1016/j.cclet.2008.10.007
Abstract:
convenient route for the synthesis of 3,4-dihydrocoumarin derivates from salicylaldehyde derivates and 1,3-dicarbonyl compounds under solvent-free microwave irradiation conditions was described. In this way, a range of compounds was obtained in moderate to good yields in a short reaction time.
convenient route for the synthesis of 3,4-dihydrocoumarin derivates from salicylaldehyde derivates and 1,3-dicarbonyl compounds under solvent-free microwave irradiation conditions was described. In this way, a range of compounds was obtained in moderate to good yields in a short reaction time.
2009, 20(1): 29-31
doi: 10.1016/j.cclet.2008.09.009
Abstract:
Six new pleuromutilin derivatives were designed and synthesized, confirmed by MS, IR and 1H NMR techniques. And the antibacterial activities were primarily evaluated in vitro. The results indicated that most of the derivatives showed more potent activities against corresponding bacterial strains than that of pleuromutilin. Especially, compounds 4d and 5b had obvious activities against salmonella compared with pleuromutilin.
Six new pleuromutilin derivatives were designed and synthesized, confirmed by MS, IR and 1H NMR techniques. And the antibacterial activities were primarily evaluated in vitro. The results indicated that most of the derivatives showed more potent activities against corresponding bacterial strains than that of pleuromutilin. Especially, compounds 4d and 5b had obvious activities against salmonella compared with pleuromutilin.
2009, 20(1): 32-36
doi: 10.1016/j.cclet.2008.10.015
Abstract:
MgBr2 performs as a novel catalyst for the synthesis of various 1,5-benzodiazepine derivatives from wide range of substituted o-phenylenediamines and various ketones in good to excellent isolated yields (93-98%) using water as solvent at ambient temperature. Several solvents were examined for this reaction; however, in terms of reaction yield and time, water was found to be the optimum solvent. The remarkable advantages offered by this method are easily and inexpensive available catalyst, simple procedure, mild conditions, much faster (40-60 min) reactions and good to excellent yields of products.
MgBr2 performs as a novel catalyst for the synthesis of various 1,5-benzodiazepine derivatives from wide range of substituted o-phenylenediamines and various ketones in good to excellent isolated yields (93-98%) using water as solvent at ambient temperature. Several solvents were examined for this reaction; however, in terms of reaction yield and time, water was found to be the optimum solvent. The remarkable advantages offered by this method are easily and inexpensive available catalyst, simple procedure, mild conditions, much faster (40-60 min) reactions and good to excellent yields of products.
2009, 20(1): 37-39
doi: 10.1016/j.cclet.2008.10.006
Abstract:
A facile procedure for the synthesis of 3-(2'-amino-3'-cyano-4'-arylpyrid-6'-yl) coumarins are being reported starting from 3-acetylcoumarin, aromatic aldehydes and malononitrile. The reactions were carried out on microwave irradiation in good yield with short time and easy work-up. The structures of all the compounds have been confirmed on the basis of their analytical, IR, 1H NMR,and mass spectral data.
A facile procedure for the synthesis of 3-(2'-amino-3'-cyano-4'-arylpyrid-6'-yl) coumarins are being reported starting from 3-acetylcoumarin, aromatic aldehydes and malononitrile. The reactions were carried out on microwave irradiation in good yield with short time and easy work-up. The structures of all the compounds have been confirmed on the basis of their analytical, IR, 1H NMR,and mass spectral data.
2009, 20(1): 40-43
doi: 10.1016/j.cclet.2008.10.013
Abstract:
In the presence of catalytic amount of In(OTf)3 (10 mol%), a series of aldimines reacted with tetraallyltin in a 2:1 molar ratio to afford the corresponding homoallylic amines in good yields. The good atom efficiency was achieved under mild reaction conditions and a new protocol (allyl)4Sn/In(OTf)3 for simple imines was developed.
In the presence of catalytic amount of In(OTf)3 (10 mol%), a series of aldimines reacted with tetraallyltin in a 2:1 molar ratio to afford the corresponding homoallylic amines in good yields. The good atom efficiency was achieved under mild reaction conditions and a new protocol (allyl)4Sn/In(OTf)3 for simple imines was developed.
2009, 20(1): 44-47
doi: 10.1016/j.cclet.2008.10.005
Abstract:
An efficient protocol for the one-pot multicomponent synthesis of various 2,4,5-triaryl-1H-imidazoles and 1,2,4,5-tetraaryl-1H-imidazoles using PEG-400 as reaction medium is described. This method has the advantages of good yields, less pollution and simple reaction conditions.
An efficient protocol for the one-pot multicomponent synthesis of various 2,4,5-triaryl-1H-imidazoles and 1,2,4,5-tetraaryl-1H-imidazoles using PEG-400 as reaction medium is described. This method has the advantages of good yields, less pollution and simple reaction conditions.
2009, 20(1): 48-51
doi: 10.1016/j.cclet.2008.10.004
Abstract:
One-pot simultaneous debrominative decarboxylation and sulfamation of anti-2,3-dibromo-3-(4-chlorosulfonylphenyl)propanoic acid in DMF (for alkyl amines) or DMF-pyridine (for aryl amines) using a diverse range of alkyl and aryl amines under microwave irradiation condition stereoselectively afforded (Z)-4-(2-bromovinyl)benzenesulfonamides in good yields.
One-pot simultaneous debrominative decarboxylation and sulfamation of anti-2,3-dibromo-3-(4-chlorosulfonylphenyl)propanoic acid in DMF (for alkyl amines) or DMF-pyridine (for aryl amines) using a diverse range of alkyl and aryl amines under microwave irradiation condition stereoselectively afforded (Z)-4-(2-bromovinyl)benzenesulfonamides in good yields.
2009, 20(1): 52-54
doi: 10.1016/j.cclet.2008.10.019
Abstract:
[1,2,4]-Triazole-[4,3-a]-quinoxaline is an important component of many drugs. The yield of the reported methods for triazole cyclization step was usually as low as 20%. In this article, the triazole cyclization step was successfully done by using microwave method with a high yield of 75% for the first time.
[1,2,4]-Triazole-[4,3-a]-quinoxaline is an important component of many drugs. The yield of the reported methods for triazole cyclization step was usually as low as 20%. In this article, the triazole cyclization step was successfully done by using microwave method with a high yield of 75% for the first time.
2009, 20(1): 55-57
doi: 10.1016/j.cclet.2008.10.003
Abstract:
An efficient and convenient approach to synthesize of ethyl arylglyoxylates by solvent-free grinding was described. Eight ethyl arylglyoxylates had been synthesized by this method, this method provided several advantages such as little pollution, high yield,good selectivity, and simple workup procedure, their structures were confirmed by IR, 1HNMR.
An efficient and convenient approach to synthesize of ethyl arylglyoxylates by solvent-free grinding was described. Eight ethyl arylglyoxylates had been synthesized by this method, this method provided several advantages such as little pollution, high yield,good selectivity, and simple workup procedure, their structures were confirmed by IR, 1HNMR.
2009, 20(1): 58-61
doi: 10.1016/j.cclet.2008.10.020
Abstract:
Five multinuclear cyclotriphosphazene ligands were synthesized and tested for their cleavage activities to plasmid DNA. All of these new compounds were confirmed by MS, 1H NMR, 31P NMR, 13C NMR and IR. Preliminary studies on the cleavage of pUC19 DNA in the presence of metal complexes were performed. The results revealed that these complexes could act as powerful catalysts under physiological conditions. The complexes 3b+Cu can effectively cleave DNA to nicked form, giving hydrolysis rate constant of 0.08/h under physiological conditions. An acid-base catalyzed DNA phosphate-diester hydrolysis mechanism was also proposed.
Five multinuclear cyclotriphosphazene ligands were synthesized and tested for their cleavage activities to plasmid DNA. All of these new compounds were confirmed by MS, 1H NMR, 31P NMR, 13C NMR and IR. Preliminary studies on the cleavage of pUC19 DNA in the presence of metal complexes were performed. The results revealed that these complexes could act as powerful catalysts under physiological conditions. The complexes 3b+Cu can effectively cleave DNA to nicked form, giving hydrolysis rate constant of 0.08/h under physiological conditions. An acid-base catalyzed DNA phosphate-diester hydrolysis mechanism was also proposed.
2009, 20(1): 62-65
doi: 10.1016/j.cclet.2008.10.008
Abstract:
An ionic liquid material containing small size cation was synthesized and its composition and structure was determined by FT-IR,1H NMR, 13C NMR and element analysis. However, its physical properties such as melting point, viscosity, conductivity, etc.were measured and the results show that the novel ionic liquid is composed of small cation with highly symmetry and larger anion which is very rare among the reported ionic liquid family.
An ionic liquid material containing small size cation was synthesized and its composition and structure was determined by FT-IR,1H NMR, 13C NMR and element analysis. However, its physical properties such as melting point, viscosity, conductivity, etc.were measured and the results show that the novel ionic liquid is composed of small cation with highly symmetry and larger anion which is very rare among the reported ionic liquid family.
2009, 20(1): 66-70
doi: 10.1016/j.cclet.2008.10.023
Abstract:
In this work, the interaction between chelerythrine (CHE) and guanosine is studied usingUV-vis and fluorescence measurements at various temperatures. The UV-vis spectra show that the increasing guanosine concentrations result in the decreasing absorption intensity and red shift of CHE E absorption band (267 nm). The fluorescence spectra are fitted to linear analysis, yielding a binding constant of 1.04×104 L/mol at 298.15 K of CHE with guanosine. Besides, with △rHmΘ=-8.26 kJ=mol, △rGmΘ=-22.90 kJ=mol,and △rSmΘ=-49.38 J/(molK)the interaction should be entropy-driven and exterothermic.
In this work, the interaction between chelerythrine (CHE) and guanosine is studied usingUV-vis and fluorescence measurements at various temperatures. The UV-vis spectra show that the increasing guanosine concentrations result in the decreasing absorption intensity and red shift of CHE E absorption band (267 nm). The fluorescence spectra are fitted to linear analysis, yielding a binding constant of 1.04×104 L/mol at 298.15 K of CHE with guanosine. Besides, with △rHmΘ=-8.26 kJ=mol, △rGmΘ=-22.90 kJ=mol,and △rSmΘ=-49.38 J/(molK)the interaction should be entropy-driven and exterothermic.
2009, 20(1): 71-75
doi: 10.1016/j.cclet.2008.09.043
Abstract:
The electrospray ionization mass spectrometry investigation showed that the binding sites of [ZnL]2+, where L is 2-[bis(2-aminoethyl)amino]ethanol, with oxidized insulin B chain are Phe1, His5 and Arg22, which lead to the selective cleavages of the peptide bonds at Phe1-Val2, His5-Leu6, Glu21-Arg22, and Arg22-Gly23 of oxidized insulin B chain.
The electrospray ionization mass spectrometry investigation showed that the binding sites of [ZnL]2+, where L is 2-[bis(2-aminoethyl)amino]ethanol, with oxidized insulin B chain are Phe1, His5 and Arg22, which lead to the selective cleavages of the peptide bonds at Phe1-Val2, His5-Leu6, Glu21-Arg22, and Arg22-Gly23 of oxidized insulin B chain.
2009, 20(1): 76-78
doi: 10.1016/j.cclet.2008.09.007
Abstract:
In the presence of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS),carboxylic group-functionalized single-walled carbon nanotubes (SWNTs) were assembled vertically on the glassy carbon electrode using ethylenediamine as linking agent to fabricate an aligned electrode (SWNTE). The morphological characteristic was studied with atomic force microscope (AFM) and its electrochemical property was investigated using K3[Fe(CN)6] as probe.ssDNA had a sensitive voltammetric response at the SWNTE and the oxidative peak potentials of guanine base and adenine base were 0.608 Vand 0.896 V, respectively. Under the optimal conditions, the DPV peak current of guanine base vs. the concentration of ssDNA was linear in the range of 5.4 μg/L-10.8 μg/L with a detection limit of 1 μg/L (S/N=3).
In the presence of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS),carboxylic group-functionalized single-walled carbon nanotubes (SWNTs) were assembled vertically on the glassy carbon electrode using ethylenediamine as linking agent to fabricate an aligned electrode (SWNTE). The morphological characteristic was studied with atomic force microscope (AFM) and its electrochemical property was investigated using K3[Fe(CN)6] as probe.ssDNA had a sensitive voltammetric response at the SWNTE and the oxidative peak potentials of guanine base and adenine base were 0.608 Vand 0.896 V, respectively. Under the optimal conditions, the DPV peak current of guanine base vs. the concentration of ssDNA was linear in the range of 5.4 μg/L-10.8 μg/L with a detection limit of 1 μg/L (S/N=3).
2009, 20(1): 79-83
doi: 10.1016/j.cclet.2008.10.012
Abstract:
pH-responsive-chitosan nanoparticles for the control release of protein drug were prepared by combining two-step crosslinking method, in which chitosan was subsequently crosslinked by sodium tripolyphosphate (TPP) and glycidoxypropyltrimethoxysilane (GPTMS). Compared with TPP crosslinked chitosan particles, the two-step crosslinked nanoparticles were not only pH-responsive but also more stable in wide pH range. Fluorescein isothiocyanate (FITC) labeled anti-human-IgG antibody was used as a model protein drug for evaluating the control release profile of the nano-carrier. The amount of released antibody increased from 5.6% to 50% when the pH of solution shifted from 7.4 to 6.0. The results suggest the possible application of the nanoparticles as pHresponsive drug delivery materials.
pH-responsive-chitosan nanoparticles for the control release of protein drug were prepared by combining two-step crosslinking method, in which chitosan was subsequently crosslinked by sodium tripolyphosphate (TPP) and glycidoxypropyltrimethoxysilane (GPTMS). Compared with TPP crosslinked chitosan particles, the two-step crosslinked nanoparticles were not only pH-responsive but also more stable in wide pH range. Fluorescein isothiocyanate (FITC) labeled anti-human-IgG antibody was used as a model protein drug for evaluating the control release profile of the nano-carrier. The amount of released antibody increased from 5.6% to 50% when the pH of solution shifted from 7.4 to 6.0. The results suggest the possible application of the nanoparticles as pHresponsive drug delivery materials.
2009, 20(1): 84-87
doi: 10.1016/j.cclet.2008.10.014
Abstract:
A sensitive method for the determination of ephedrine and codeine in human urine by capillary electrophoresis (CE) was described. In order to improve the sensitivity, two online concentration techniques including cation-selective exhaustive injection (CSEI) and sweeping micellar electrokinetic chromatography (sweeping-MEKC) were used. Under the optimum conditions, the detection limits (S/N=3) were 0.10 μg/L for ephedrine and 0.80 μg/L for codeine. This method was successfully applied to real urine sample analysis.
A sensitive method for the determination of ephedrine and codeine in human urine by capillary electrophoresis (CE) was described. In order to improve the sensitivity, two online concentration techniques including cation-selective exhaustive injection (CSEI) and sweeping micellar electrokinetic chromatography (sweeping-MEKC) were used. Under the optimum conditions, the detection limits (S/N=3) were 0.10 μg/L for ephedrine and 0.80 μg/L for codeine. This method was successfully applied to real urine sample analysis.
2009, 20(1): 88-91
doi: 10.1016/j.cclet.2008.10.021
Abstract:
A novel method for the determination of captopril by spectrophotometer is described in this paper. The experiment is based on the fact that Fe(Ⅲ) is reduced to Fe(Ⅱ) by captopril, then the in situ formed Fe(Ⅱ) reacts with potassium ferricyanide to give the soluble prussian blue at pH 4.00, and its maximal adsorption wavelength (λmax) is 735 nm. Good linear relationship is obtained between the absorbance and the concentration of captopril in the wide range of 0.05-20 μg/mL. The linear regression equation is A=-0.04314+0.11423C (μg/mL) with a correlation coefficient R=0.9998. The detection limit (3σ/k) is 0.04 μg/mL, the molar absorption coefficient is 2.5×104 L/mol cm. By mensurating the absorbance of soluble prussian blue, the indirect determination of captopril can be obtained. This method has been successfully applied to determination of captopril in pharmaceutical samples.Analytical results obtained are satisfactory.
A novel method for the determination of captopril by spectrophotometer is described in this paper. The experiment is based on the fact that Fe(Ⅲ) is reduced to Fe(Ⅱ) by captopril, then the in situ formed Fe(Ⅱ) reacts with potassium ferricyanide to give the soluble prussian blue at pH 4.00, and its maximal adsorption wavelength (λmax) is 735 nm. Good linear relationship is obtained between the absorbance and the concentration of captopril in the wide range of 0.05-20 μg/mL. The linear regression equation is A=-0.04314+0.11423C (μg/mL) with a correlation coefficient R=0.9998. The detection limit (3σ/k) is 0.04 μg/mL, the molar absorption coefficient is 2.5×104 L/mol cm. By mensurating the absorbance of soluble prussian blue, the indirect determination of captopril can be obtained. This method has been successfully applied to determination of captopril in pharmaceutical samples.Analytical results obtained are satisfactory.
2009, 20(1): 92-95
doi: 10.1016/j.cclet.2008.10.001
Abstract:
The addition of 5-10 mL min-1 nitrogen to the central channel of plasma in Laser ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) increases the sensitivities of Cd by a factor of 3 and decreases oxide interferences by one order of magnitude, which allows the direct analysis of trace levels of Cd in glass samples. This simple method shows a great potential for the direct determination of Cd in various kinds of samples.
The addition of 5-10 mL min-1 nitrogen to the central channel of plasma in Laser ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) increases the sensitivities of Cd by a factor of 3 and decreases oxide interferences by one order of magnitude, which allows the direct analysis of trace levels of Cd in glass samples. This simple method shows a great potential for the direct determination of Cd in various kinds of samples.
2009, 20(1): 96-98
doi: 10.1016/j.cclet.2008.09.036
Abstract:
The effect of rare earths (Sm, Pr, Ce, Nd and La) on the hydrogenation properties of p-chloronitrobenzene (CNB) over Pt/CNTs catalyst was studied in ethanol at 303 K and normal pressure. The results exhibited that the hydrogenation of p-CNB could be carried out over PtMOx/CNTs catalysts. Both catalytic activities and yields of p-chloroaniline (CAN) were all improved. PtCeOx/ CNTs catalyst exhibited the best catalytic activity (TOF was 0.47 s-1) and the highest yield of p-CAN (97.5 mol%). PtCeOx/CNTs (1.0 wt%) catalyst exhibited good stability on the hydrogenation of p-CNB.
The effect of rare earths (Sm, Pr, Ce, Nd and La) on the hydrogenation properties of p-chloronitrobenzene (CNB) over Pt/CNTs catalyst was studied in ethanol at 303 K and normal pressure. The results exhibited that the hydrogenation of p-CNB could be carried out over PtMOx/CNTs catalysts. Both catalytic activities and yields of p-chloroaniline (CAN) were all improved. PtCeOx/ CNTs catalyst exhibited the best catalytic activity (TOF was 0.47 s-1) and the highest yield of p-CAN (97.5 mol%). PtCeOx/CNTs (1.0 wt%) catalyst exhibited good stability on the hydrogenation of p-CNB.
2009, 20(1): 99-101
doi: 10.1016/j.cclet.2008.09.058
Abstract:
Magnetic field was tentatively introduced into Fenton reactions system for the degradation and discoloration of methyl blue as the represent of organic chemical dye, which was a bio-refractory organic pollutant in industry wastewater. It was found that under optimal Fenton reaction conditions, with the assistant of magnetic field in Fenton reactions, the degradation rate of methyl blue, the decomposition rate of H2O2 and the conversion rate of Fe2+ were accelerated, the extent of them would be improved by the increase of magnetic field intensity. Meanwhile, the mineralization of methyl blue (CODcr) was improved by over 10% with magnetic field.
Magnetic field was tentatively introduced into Fenton reactions system for the degradation and discoloration of methyl blue as the represent of organic chemical dye, which was a bio-refractory organic pollutant in industry wastewater. It was found that under optimal Fenton reaction conditions, with the assistant of magnetic field in Fenton reactions, the degradation rate of methyl blue, the decomposition rate of H2O2 and the conversion rate of Fe2+ were accelerated, the extent of them would be improved by the increase of magnetic field intensity. Meanwhile, the mineralization of methyl blue (CODcr) was improved by over 10% with magnetic field.
2009, 20(1): 102-105
doi: 10.1016/j.cclet.2008.09.059
Abstract:
Three kinds of Pt/alumina catalysts were prepared by impregnation-hydrogen reduction, impregnation-hydrazine reduction and electroless plating methods. Their differences in the structures, specific areas and particle sizes were characterized by XRD, BET and TEM, respectively. Furthermore, their catalytic activities for the hydrogen iodide (HI) decomposition were evaluated in a fixed bed reactor. The results show that the catalyst 5%Pt/Al2O3 prepared by the electroless plating has the optimum catalytic properties for HI decomposition owing to the high dispersion of the platinum nano-particles (<5 nm) on the alumina supports.
Three kinds of Pt/alumina catalysts were prepared by impregnation-hydrogen reduction, impregnation-hydrazine reduction and electroless plating methods. Their differences in the structures, specific areas and particle sizes were characterized by XRD, BET and TEM, respectively. Furthermore, their catalytic activities for the hydrogen iodide (HI) decomposition were evaluated in a fixed bed reactor. The results show that the catalyst 5%Pt/Al2O3 prepared by the electroless plating has the optimum catalytic properties for HI decomposition owing to the high dispersion of the platinum nano-particles (<5 nm) on the alumina supports.
2009, 20(1): 106-110
doi: 10.1016/j.cclet.2008.09.032
Abstract:
Phosphor of KMgF3:Ce3+ is synthesized through solvothermal method at 180℃ and characterized by means of X-ray powder diffraction (XRD) and environment scanning electron microscopy (ESEM). X-ray photoelectron spectroscopy (XPS) is applied to the study of the energy band structure of KMgF3:Ce3+ and confirms the oxygen content of the product is very low. The fluorescence spectra of the rare-earth ion-doped KMgF3 is investigated by the fluorescence spectrophotometer. In the emission spectra, there is a broadband emission with a maximum center located at 306 nm arising from d-f transition of Ce3+ in the host. This will be useful for ultraviolet tunable lasers.
Phosphor of KMgF3:Ce3+ is synthesized through solvothermal method at 180℃ and characterized by means of X-ray powder diffraction (XRD) and environment scanning electron microscopy (ESEM). X-ray photoelectron spectroscopy (XPS) is applied to the study of the energy band structure of KMgF3:Ce3+ and confirms the oxygen content of the product is very low. The fluorescence spectra of the rare-earth ion-doped KMgF3 is investigated by the fluorescence spectrophotometer. In the emission spectra, there is a broadband emission with a maximum center located at 306 nm arising from d-f transition of Ce3+ in the host. This will be useful for ultraviolet tunable lasers.
2009, 20(1): 111-114
doi: 10.1016/j.cclet.2008.09.003
Abstract:
Novel complex hydrogels of methylcellulose (MC) and poly(vinyl alcohol) (PVA) with wide-spectrum thermoresponsivity were prepared via physical and mild process. Thermal phase transition of MC/PVA hydrogels exhibited two forms including sol/sol to gel/sol and sol/gel to gel/gel. The phase transition temperature of MC/PVA solution ranged from 38.7 to 60.6℃ and was able to be adjusted by simply changing the feeding ratios of two components. The interior morphology of MC/PVA gels was examined with fluorescence analysis and scanning electron microscopy analysis, which showed that MC was well dispersed in matrix before and after thermally gelling.
Novel complex hydrogels of methylcellulose (MC) and poly(vinyl alcohol) (PVA) with wide-spectrum thermoresponsivity were prepared via physical and mild process. Thermal phase transition of MC/PVA hydrogels exhibited two forms including sol/sol to gel/sol and sol/gel to gel/gel. The phase transition temperature of MC/PVA solution ranged from 38.7 to 60.6℃ and was able to be adjusted by simply changing the feeding ratios of two components. The interior morphology of MC/PVA gels was examined with fluorescence analysis and scanning electron microscopy analysis, which showed that MC was well dispersed in matrix before and after thermally gelling.
2009, 20(1): 115-118
doi: 10.1016/j.cclet.2008.09.060
Abstract:
The mixing soft-segment WPU (waterborne polyurethane) polymer electrolytes were synthesized by using PEO (poly(ethylene oxide)) and PDMS (polydimethylsiloxane) as the soft segments. These polymer electrolytes exhibit good thermal and electrochemical stability. The conductivity of the gel polymer electrolyte is 2.52×10-3 S/cm at 25℃ with the LiTFSI/(DMC+EC) content of 130%.
The mixing soft-segment WPU (waterborne polyurethane) polymer electrolytes were synthesized by using PEO (poly(ethylene oxide)) and PDMS (polydimethylsiloxane) as the soft segments. These polymer electrolytes exhibit good thermal and electrochemical stability. The conductivity of the gel polymer electrolyte is 2.52×10-3 S/cm at 25℃ with the LiTFSI/(DMC+EC) content of 130%.
2009, 20(1): 119-122
doi: 10.1016/j.cclet.2008.09.061
Abstract:
The interaction of overbased salicylate detergents with zinc dialkyldithiophosphates (ZDDP) and its effect on the formation of tribofilms under boundary lubrication have been studied by means of X-ray absorption near-edge structure spectroscopy. The results show that addition of metallic detergents to neat ZDDP results in the change of surface chemistry of the tribofilm formed from neat ZDDP. Calcium from detergents is digested in the tribofilm. For the high overbased detergents, the deposit of overbasing agent CaCO3 in the tribofilm is also observed along with the formation of calcium phosphate in tribofilms.
The interaction of overbased salicylate detergents with zinc dialkyldithiophosphates (ZDDP) and its effect on the formation of tribofilms under boundary lubrication have been studied by means of X-ray absorption near-edge structure spectroscopy. The results show that addition of metallic detergents to neat ZDDP results in the change of surface chemistry of the tribofilm formed from neat ZDDP. Calcium from detergents is digested in the tribofilm. For the high overbased detergents, the deposit of overbasing agent CaCO3 in the tribofilm is also observed along with the formation of calcium phosphate in tribofilms.
2009, 20(1): 123-126
doi: 10.1016/j.cclet.2008.10.009
Abstract:
We demonstrated a simple and effective dual-templating approach for the synthesis of hierarchically mesocellular carbon foams by using nonionic surfactant of sorbitan monooleate and silica colloid particles as sacrificial templates, and resorcinol/ formaldehyde as carbon source. The representative carbon foam has dual mesopore sizes of 4 and 10 nm, and possesses the specific surface area of 580 m2/g and the total pore volume of 0.80 cm3/g.
We demonstrated a simple and effective dual-templating approach for the synthesis of hierarchically mesocellular carbon foams by using nonionic surfactant of sorbitan monooleate and silica colloid particles as sacrificial templates, and resorcinol/ formaldehyde as carbon source. The representative carbon foam has dual mesopore sizes of 4 and 10 nm, and possesses the specific surface area of 580 m2/g and the total pore volume of 0.80 cm3/g.
