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2011 Volume 22 Issue 6
2011, 22(6): 573-756
doi: 10.1016/j.cclet.2010.12.016
Abstract:
Nano-TiO2 as an eco-friendly and efficient nanocatalyst was applied for quinoxaline preparation with improved yield.In this protocol, diketones and 1.2-diamines were condensed in the presence of catalyst at room temperature.
Nano-TiO2 as an eco-friendly and efficient nanocatalyst was applied for quinoxaline preparation with improved yield.In this protocol, diketones and 1.2-diamines were condensed in the presence of catalyst at room temperature.
2011, 22(6): 631-634
doi: 10.1016/j.cclet.2010.12.039
Abstract:
The first synthesis of the naturally occurring cyclic peptide euryjanicin B has been achieved.A general method was described to synthesize the cyclic peptide by a two-step solid-phase/solution synthesis strategy.All the amino acids in this study are L-configuration, The linear heptapeptide was assembled by standard Fmoc chemistry on solid-phase and subsequently cyclization was carried out by solution method.
The first synthesis of the naturally occurring cyclic peptide euryjanicin B has been achieved.A general method was described to synthesize the cyclic peptide by a two-step solid-phase/solution synthesis strategy.All the amino acids in this study are L-configuration, The linear heptapeptide was assembled by standard Fmoc chemistry on solid-phase and subsequently cyclization was carried out by solution method.
2011, 22(6): 635-638
doi: 10.1016/j.cclet.2010.12.033
Abstract:
Amphiphilic hydroxyl functioned polyester(HFP)can be used as compatibilizers for blends of starch and resins.We developed a synthetic method for effective preparation of HFPs.Water was removed by high flow rate N2 rather than high vacuum during polycondensation of sebacic acid with xylitol, sorbitol, or mannitol in the presence of dehydrative condensation catalyst and the product is with [η] of 27.2 mL/g, Mn of 1903, Mw of 167,693, Tg of-30.5 ℃, Tm of 44.0 ℃.Weight loss is 1.73% under 200 ℃.The integral distributions of molecular weight are 43.6 wt% and 63.8 wt% over 10,000 and 3000, respectively.The results indicated that higher molecular weight HFP was economically synthesized.
Amphiphilic hydroxyl functioned polyester(HFP)can be used as compatibilizers for blends of starch and resins.We developed a synthetic method for effective preparation of HFPs.Water was removed by high flow rate N2 rather than high vacuum during polycondensation of sebacic acid with xylitol, sorbitol, or mannitol in the presence of dehydrative condensation catalyst and the product is with [η] of 27.2 mL/g, Mn of 1903, Mw of 167,693, Tg of-30.5 ℃, Tm of 44.0 ℃.Weight loss is 1.73% under 200 ℃.The integral distributions of molecular weight are 43.6 wt% and 63.8 wt% over 10,000 and 3000, respectively.The results indicated that higher molecular weight HFP was economically synthesized.
2011, 22(6): 639-642
doi: 10.1016/j.cclet.2010.12.034
Abstract:
FeOx/HZSM-5 catalyst with 8 wt.% Fe-loading(8-FeZ)exhibited significantly higher reactivity in the benzylation of benzene with benzyl chloride than FeOx/HZSM-5 catalyst with 2.5 wt.% Fe-loading(2.5-FeZ)because the synergistic catalysis between isolated Fe3+ and superfine Fe2O3 occurred on 8-FeZ in the reaction.
FeOx/HZSM-5 catalyst with 8 wt.% Fe-loading(8-FeZ)exhibited significantly higher reactivity in the benzylation of benzene with benzyl chloride than FeOx/HZSM-5 catalyst with 2.5 wt.% Fe-loading(2.5-FeZ)because the synergistic catalysis between isolated Fe3+ and superfine Fe2O3 occurred on 8-FeZ in the reaction.
2011, 22(6): 643-646
doi: 10.1016/j.cclet.2010.12.044
Abstract:
A new method for the preparation of SB A-15-supported palladium catalyst for Heck reaction in supercritical carbon dioxide was presented.The newly formed SBA-15-supported palladium catalyst(Ph-SBA-15-PPh3-Pd)exhibited high catalytic activity for the Heck reaction of 4-nitrobromobenzene with methyl acrylate.The catalyst can be reused several times without a loss of activity.
A new method for the preparation of SB A-15-supported palladium catalyst for Heck reaction in supercritical carbon dioxide was presented.The newly formed SBA-15-supported palladium catalyst(Ph-SBA-15-PPh3-Pd)exhibited high catalytic activity for the Heck reaction of 4-nitrobromobenzene with methyl acrylate.The catalyst can be reused several times without a loss of activity.
2011, 22(6): 647-650
doi: 10.1016/j.cclet.2010.12.005
Abstract:
A new acid-base fluorescent switch containing both imidazo [4,5-f] [1,10]-phenanthroline and triphenylamine groups has been synthesized.Its fluorescence emissions and absorptions can be reversibly changed through protonation/deprotonation of imidazole and amine moiety by controlling the intramolecular charge transfer(ICT)process, leading to off-on-off fluorescent molecular switching.
A new acid-base fluorescent switch containing both imidazo [4,5-f] [1,10]-phenanthroline and triphenylamine groups has been synthesized.Its fluorescence emissions and absorptions can be reversibly changed through protonation/deprotonation of imidazole and amine moiety by controlling the intramolecular charge transfer(ICT)process, leading to off-on-off fluorescent molecular switching.
2011, 22(6): 651-654
doi: 10.1016/j.cclet.2010.12.025
Abstract:
A new acid-base fluorescent switch containing both imidazo[4,5-f][1,10]-phenanthroline and triphenylamine groups has been synthesized.Its fluorescence emissions and absorptions can be reversibly changed through protonation/deprotonation of imidazole and amine moiety by controlling the intramolecular charge transfer(ICT)process, leading to off-on-off fluorescent molecular switching.
A new acid-base fluorescent switch containing both imidazo[4,5-f][1,10]-phenanthroline and triphenylamine groups has been synthesized.Its fluorescence emissions and absorptions can be reversibly changed through protonation/deprotonation of imidazole and amine moiety by controlling the intramolecular charge transfer(ICT)process, leading to off-on-off fluorescent molecular switching.
2011, 22(6): 655-658
doi: 10.1016/j.cclet.2010.12.027
Abstract:
O-Alkylation of oximes with N-vinylpyrrolidin-2-one or iV-methyl-N-vinylacetamide was efficiently initiated by a catalytic amount of cerium(IV)ammonium nitrate(CAN), giving the corresponding oxime ether derivatives in good yield.
O-Alkylation of oximes with N-vinylpyrrolidin-2-one or iV-methyl-N-vinylacetamide was efficiently initiated by a catalytic amount of cerium(IV)ammonium nitrate(CAN), giving the corresponding oxime ether derivatives in good yield.
2011, 22(6): 659-662
doi: 10.1016/j.cclet.2010.11.025
Abstract:
1,4-Bis(triphenylphosphonium)-2-butene dichloride(BTPBDC)and 1,4-bis(triphenyl phosphonium)-2-butene dithiocyanate(BTPBDT)were prepared and used as phase-transfer catalysts.Alkyl halides were converted efficiently to the corresponding alkyl thiocyanates under mild reaction conditions in water.No evidence for the formation of isothiocy anates as by-product of the reaction was observed.
1,4-Bis(triphenylphosphonium)-2-butene dichloride(BTPBDC)and 1,4-bis(triphenyl phosphonium)-2-butene dithiocyanate(BTPBDT)were prepared and used as phase-transfer catalysts.Alkyl halides were converted efficiently to the corresponding alkyl thiocyanates under mild reaction conditions in water.No evidence for the formation of isothiocy anates as by-product of the reaction was observed.
2011, 22(6): 663-666
doi: 10.1016/j.cclet.2010.12.028
Abstract:
Ten coumarin derivatives containing(E)-methyl 2-(methoxyimino)-2-phenylacetate were synthesized and bioassayed.The compounds were identified by IR, 1H NMR and elemental analyses.The test results indicated that compound 5j(R1 is methyl and R2 is n-C6H13)was the optimal structure in this paper with good fungicidal activity against CDM(85%)at 6.25 mg/L concentration.
Ten coumarin derivatives containing(E)-methyl 2-(methoxyimino)-2-phenylacetate were synthesized and bioassayed.The compounds were identified by IR, 1H NMR and elemental analyses.The test results indicated that compound 5j(R1 is methyl and R2 is n-C6H13)was the optimal structure in this paper with good fungicidal activity against CDM(85%)at 6.25 mg/L concentration.
2011, 22(6): 671-674
doi: 10.1016/j.cclet.2010.12.038
Abstract:
A domino reaction of anilines with cyclic and acyclic enol ethers induced by catalytic amounts of TBPA·+(5 mol%)was investigated and a series of 2,4-disubstituted-1,2,3,4-tetrahydroquinolines were synthesized.Different from cyclic enol ethers, when acyclic enol ethers were used in the reaction, they serve as surrogates of acetaldehyde, producing a series of 2-methyl-4-anilino-1,2,3,4-tetrahydroquinolines.A single electron transfer mechanism was proposed to rationalize the products formation.
A domino reaction of anilines with cyclic and acyclic enol ethers induced by catalytic amounts of TBPA·+(5 mol%)was investigated and a series of 2,4-disubstituted-1,2,3,4-tetrahydroquinolines were synthesized.Different from cyclic enol ethers, when acyclic enol ethers were used in the reaction, they serve as surrogates of acetaldehyde, producing a series of 2-methyl-4-anilino-1,2,3,4-tetrahydroquinolines.A single electron transfer mechanism was proposed to rationalize the products formation.
2011, 22(6): 675-678
doi: 10.1016/j.cclet.2010.12.018
Abstract:
The coupling reaction of phenylurea with different functionalized aryl halides in the presence of air stable Cul, N,N-dimethylethylenediamine as a ligand, and K3PO4 as a base gives symmetrical and unsymmetrical diarylureas in relatively high yields.This method is milder than the palladium catalyzed arylation and avoids the use of toxic phosphine ligands.
The coupling reaction of phenylurea with different functionalized aryl halides in the presence of air stable Cul, N,N-dimethylethylenediamine as a ligand, and K3PO4 as a base gives symmetrical and unsymmetrical diarylureas in relatively high yields.This method is milder than the palladium catalyzed arylation and avoids the use of toxic phosphine ligands.
2011, 22(6): 677-670
doi: 10.1016/j.cclet.2010.12.017
Abstract:
Two bioactive natural 4-arylcoumarins, 5,7,4'-trimethoxy-4-phenylcoumarin(1a), 5,7-dimethoxy-4-phenylcoumarin(1b)and five closely related derivatives 1c-g were synthesized.In vitro evaluation with a catechol subunit for antioxidant and antimicrobial activity, these compounds using standard methods showed that compounds 1d, 1f displayed promise radical scavenging activity and 1f was found to be the most active one against Bacillus dysenteriae.
Two bioactive natural 4-arylcoumarins, 5,7,4'-trimethoxy-4-phenylcoumarin(1a), 5,7-dimethoxy-4-phenylcoumarin(1b)and five closely related derivatives 1c-g were synthesized.In vitro evaluation with a catechol subunit for antioxidant and antimicrobial activity, these compounds using standard methods showed that compounds 1d, 1f displayed promise radical scavenging activity and 1f was found to be the most active one against Bacillus dysenteriae.
2011, 22(6): 679-682
doi: 10.1016/j.cclet.2010.12.041
Abstract:
A self-intermolecular cyclocondensation reaction of 3,4-dihydropyrimidine-2-thione(DHPM)to give a novel tricyclic structure containing DHPM core in the presence of diethyl azodicarboxylate(DEAD)and triphenylphosphine(TPP)at room temperature is reported.
A self-intermolecular cyclocondensation reaction of 3,4-dihydropyrimidine-2-thione(DHPM)to give a novel tricyclic structure containing DHPM core in the presence of diethyl azodicarboxylate(DEAD)and triphenylphosphine(TPP)at room temperature is reported.
2011, 22(6): 683-686
doi: 10.1016/j.cclet.2010.11.037
Abstract:
Mesoporous MCM-41 and Fe loaded MCM-41(Fe/MCM-41), which were successfully prepared by a hydrothermal method and a dipping method respectively, were applied as heterogeneous catalysts for ozonation of p-chlorobenzoic acid(p-CBA)in aqueous solution.MCM-41 and Fe/MCM-41 were characterized by XRD, FT-IR and diffuse reflectance UV-vis(DR-UV-vis)techniques.The presence of either MCM-41 or Fe/MCM-41 improves p-CBA and total organic carbon(TOC)removal efficiency compared to ozonation alone.Under the experimental condition, TOC removal rate of Fe/MCM-41/O3 process is over 63.5% at 60 min oxidation time, 44.5% using MCM-41 as catalyst, only 37.7% with ozonation alone.The presence of /erf-butanol(TBA)in the Fe/MCM-41/ O3 process indicated that the oxidation mechanism of ρ-CBA occurs via OH in the liquid bulk.And Fe/MCM-41 is a promising catalyst.
Mesoporous MCM-41 and Fe loaded MCM-41(Fe/MCM-41), which were successfully prepared by a hydrothermal method and a dipping method respectively, were applied as heterogeneous catalysts for ozonation of p-chlorobenzoic acid(p-CBA)in aqueous solution.MCM-41 and Fe/MCM-41 were characterized by XRD, FT-IR and diffuse reflectance UV-vis(DR-UV-vis)techniques.The presence of either MCM-41 or Fe/MCM-41 improves p-CBA and total organic carbon(TOC)removal efficiency compared to ozonation alone.Under the experimental condition, TOC removal rate of Fe/MCM-41/O3 process is over 63.5% at 60 min oxidation time, 44.5% using MCM-41 as catalyst, only 37.7% with ozonation alone.The presence of /erf-butanol(TBA)in the Fe/MCM-41/ O3 process indicated that the oxidation mechanism of ρ-CBA occurs via OH in the liquid bulk.And Fe/MCM-41 is a promising catalyst.
2011, 22(6): 687-690
doi: 10.1016/j.cclet.2010.12.050
Abstract:
In the presence of catalytic amount of cesium hydroxide the hydrothiolation of alkynyl selenides occurred at room temperature in DMF under nitrogen atmosphere to give exclusive(Z)-1-organoseleno-2-arylthio-1-alkene in excellent yields.It could provide a new and expedient way for the preparation of(Z)-1-arylseleno-2-arylthio-1-alkene.
In the presence of catalytic amount of cesium hydroxide the hydrothiolation of alkynyl selenides occurred at room temperature in DMF under nitrogen atmosphere to give exclusive(Z)-1-organoseleno-2-arylthio-1-alkene in excellent yields.It could provide a new and expedient way for the preparation of(Z)-1-arylseleno-2-arylthio-1-alkene.
2011, 22(6): 691-693
doi: 10.1016/j.cclet.2010.12.035
Abstract:
The water soluble catalytic system comprising of CuCl2 and 2,2-biquinoline-4,4-dicarboxylic acid dipotassium salt(BQC)is highly efficient organic metallic catalysts for selective oxidation of benzylic and alicyclic compounds to the corresponding ketones, ex:indan to indanone, ethyl benzene to acetophenone.
The water soluble catalytic system comprising of CuCl2 and 2,2-biquinoline-4,4-dicarboxylic acid dipotassium salt(BQC)is highly efficient organic metallic catalysts for selective oxidation of benzylic and alicyclic compounds to the corresponding ketones, ex:indan to indanone, ethyl benzene to acetophenone.
2011, 22(6): 694-696
doi: 10.1016/j.cclet.2010.12.023
Abstract:
A new pyromeconic acid derivative, pyromeconic acid-3-O-β-D-glucopyranoside-3'-(O-β-D-glucopyranoside)-6'-(O-4"-hydro-xybenzoate)(1), along with two known ones, were isolated from the whole plants of Conyza canadensis.Their structures were elucidated based on the analysis of their spectroscopic data.The in vitro antibacterial testing results showed that all of these three compounds were inactive towards two bacterial strains, Escherichia coli and Staphyloccocus aureus.
A new pyromeconic acid derivative, pyromeconic acid-3-O-β-D-glucopyranoside-3'-(O-β-D-glucopyranoside)-6'-(O-4"-hydro-xybenzoate)(1), along with two known ones, were isolated from the whole plants of Conyza canadensis.Their structures were elucidated based on the analysis of their spectroscopic data.The in vitro antibacterial testing results showed that all of these three compounds were inactive towards two bacterial strains, Escherichia coli and Staphyloccocus aureus.
2011, 22(6): 697-700
doi: 10.1016/j.cclet.2010.12.045
Abstract:
A new triterpene saponin with 28-nor-urs-12(13),18(17)-dien-3β-ol as aglycone, named ilexsaponin C(1)was isolated from the roots of Ilex pubescens, together with three known saponins 2, 3 and 4.The structure of 1 was elucidated on the basis of spectral analysis including ID and 2D NMR and HR-ESI-MS.Saponins 1 and 4 exhibited significant XOD inhibitory activity in the test.
A new triterpene saponin with 28-nor-urs-12(13),18(17)-dien-3β-ol as aglycone, named ilexsaponin C(1)was isolated from the roots of Ilex pubescens, together with three known saponins 2, 3 and 4.The structure of 1 was elucidated on the basis of spectral analysis including ID and 2D NMR and HR-ESI-MS.Saponins 1 and 4 exhibited significant XOD inhibitory activity in the test.
2011, 22(6): 701-704
doi: 10.1016/j.cclet.2010.10.056
Abstract:
N1,N2-Bis [1-(2-hydroxyphenyl)methylidene]ethanedihydrazide(MEH)was used as new compound which plays the role of an excellent ion carrier in the fabrication of a Ho(Ⅲ)membrane electrode.The electrode shows a good selectivity for Ho(Ⅲ)ion with respect to most common cations including alkali, alkaline earth, transition and heavy metal ions.This electrode has a wide linear dynamic range from 1.0×10-6 to 1.0×10-2 mol/L with a Nernstian slope of 19.8±0.3 mV per decade and a low detection limit of 5.8×10-7 mol/L in the pH range of 2.5-9.8, while the response time was rapid( < 10 s).The suggested sensor was applied to the determination of Ho(Ⅲ)ions in tap water and river water samples.
N1,N2-Bis [1-(2-hydroxyphenyl)methylidene]ethanedihydrazide(MEH)was used as new compound which plays the role of an excellent ion carrier in the fabrication of a Ho(Ⅲ)membrane electrode.The electrode shows a good selectivity for Ho(Ⅲ)ion with respect to most common cations including alkali, alkaline earth, transition and heavy metal ions.This electrode has a wide linear dynamic range from 1.0×10-6 to 1.0×10-2 mol/L with a Nernstian slope of 19.8±0.3 mV per decade and a low detection limit of 5.8×10-7 mol/L in the pH range of 2.5-9.8, while the response time was rapid( < 10 s).The suggested sensor was applied to the determination of Ho(Ⅲ)ions in tap water and river water samples.
2011, 22(6): 705-708
doi: 10.1016/j.cclet.2010.11.035
Abstract:
A sensitive and selective electrochemical method for the determination of epinephrine(EP)was developed using a modified carbon paste electrode(MCPE)with 2,2'- [3,6-dioxa-l,8-octanediylbis(nitriloethylidyne)]-bis-hydroquinone(DOH).Cyclic vol-tammetry was used to investigate the redox properties of this modified electrode at various solution pH values and at various scan rates.In differential pulse voltammetry, the modified electrode could separate the oxidation peak potentials of EP and uric acid(UA)present in the solution but at the unmodified CPE the peak potentials were indistinguishable.This method was also examined for determination of EP in EP injection.
A sensitive and selective electrochemical method for the determination of epinephrine(EP)was developed using a modified carbon paste electrode(MCPE)with 2,2'- [3,6-dioxa-l,8-octanediylbis(nitriloethylidyne)]-bis-hydroquinone(DOH).Cyclic vol-tammetry was used to investigate the redox properties of this modified electrode at various solution pH values and at various scan rates.In differential pulse voltammetry, the modified electrode could separate the oxidation peak potentials of EP and uric acid(UA)present in the solution but at the unmodified CPE the peak potentials were indistinguishable.This method was also examined for determination of EP in EP injection.
2011, 22(6): 709-712
doi: 10.1016/j.cclet.2010.12.006
Abstract:
In this paper the effect of temperature on the mechanoluminescence of Au doped phosphors of(Zn,Cd)S is described.It is found that the ML disappears beyond a particular temperature.The temperature dependence of ML intensity follows the relationiI=IT0(1-T/TC)n, where IT0 is a constant, n is the slop of log IT versus log(1- T/TC)plot which lies between 0.9 and 1.10, TC is the temperature at which ML disappear.It is found that the ML intensity in(Zn,Cd)S:Au disappear at 600 K.
In this paper the effect of temperature on the mechanoluminescence of Au doped phosphors of(Zn,Cd)S is described.It is found that the ML disappears beyond a particular temperature.The temperature dependence of ML intensity follows the relationiI=IT0(1-T/TC)n, where IT0 is a constant, n is the slop of log IT versus log(1- T/TC)plot which lies between 0.9 and 1.10, TC is the temperature at which ML disappear.It is found that the ML intensity in(Zn,Cd)S:Au disappear at 600 K.
2011, 22(6): 713-716
doi: 10.1016/j.cclet.2010.12.040
Abstract:
In this paper, it was found that Ru(H2bpp)2(PF6)2(H2bpp=2,6-bis(pyrazol-3-yl)pyridine)complex had excellent electrochemical activity at the carbon paste electrode in the buffer solution of Tris-HCl(pH 7.0)with a couple reversible redox peaks at 0.296 V and 0.348 V, respectively.Voltammetry was used to investigate the electrochemical behavior of Ru(H2bpp)2(PF6)2 and the interaction between Ru(H2bpp)2(PF6)2 and bovine serum albumin(BSA).In the present of BSA, the oxidation peak current of Ru(H2bpp)2(PF6)2 complex was decreased linearly and the decrease of oxidation peak current of Ru(H2bpp)2(PF6)2 is proportional to BSA concentration from 0.1 to 2.5 mg/L with a detection limit 0.02 mg/L.
In this paper, it was found that Ru(H2bpp)2(PF6)2(H2bpp=2,6-bis(pyrazol-3-yl)pyridine)complex had excellent electrochemical activity at the carbon paste electrode in the buffer solution of Tris-HCl(pH 7.0)with a couple reversible redox peaks at 0.296 V and 0.348 V, respectively.Voltammetry was used to investigate the electrochemical behavior of Ru(H2bpp)2(PF6)2 and the interaction between Ru(H2bpp)2(PF6)2 and bovine serum albumin(BSA).In the present of BSA, the oxidation peak current of Ru(H2bpp)2(PF6)2 complex was decreased linearly and the decrease of oxidation peak current of Ru(H2bpp)2(PF6)2 is proportional to BSA concentration from 0.1 to 2.5 mg/L with a detection limit 0.02 mg/L.
Interaction between Janus Green B and bovine serum albumin:Electrochemistry and spectroscopy studies
2011, 22(6): 717-720
doi: 10.1016/j.cclet.2010.12.007
Abstract:
In this study, voltammetric and spectroscopic investigation of the interaction between Janus Green B(JGB)and bovine serum albumin(BSA)was reported.The interaction was observed at Britton-Robinson buffer(pH 7.0).When JGB was added to solution containing BSA, the peak currents of BSA decrease with the increasing of JGB concentrations which is due to the interaction of JGB and BSA.The binding constant of JGB with BSA was obtained by voltammetric data.Also, this interaction was supported by means of UV-vis spectroscopic measurements.The UV-vis absorption spectra of JGB in the presence of BSA decrease with the increasing of BSA concentrations.
In this study, voltammetric and spectroscopic investigation of the interaction between Janus Green B(JGB)and bovine serum albumin(BSA)was reported.The interaction was observed at Britton-Robinson buffer(pH 7.0).When JGB was added to solution containing BSA, the peak currents of BSA decrease with the increasing of JGB concentrations which is due to the interaction of JGB and BSA.The binding constant of JGB with BSA was obtained by voltammetric data.Also, this interaction was supported by means of UV-vis spectroscopic measurements.The UV-vis absorption spectra of JGB in the presence of BSA decrease with the increasing of BSA concentrations.
2011, 22(6): 721-724
doi: 10.1016/j.cclet.2010.11.024
Abstract:
A novel method to prepare surface plasmon resonance(SPR)sensor chips based on grafted imprinted polymer is explored.Benzophenone photografting system is used to grow molecularly imprinted polymer(MIP)films from the modified surface of gold substrate.The surface morphology and thickness of MIP films were investigated by scanning electronic microscope(SEM).The adsorption properties of sensor chip were studied by SPR spectroscopy.The results demonstrate that nano-MIP films can be constructed on the surface of gold substrate with the good adsorption of template molecules.
A novel method to prepare surface plasmon resonance(SPR)sensor chips based on grafted imprinted polymer is explored.Benzophenone photografting system is used to grow molecularly imprinted polymer(MIP)films from the modified surface of gold substrate.The surface morphology and thickness of MIP films were investigated by scanning electronic microscope(SEM).The adsorption properties of sensor chip were studied by SPR spectroscopy.The results demonstrate that nano-MIP films can be constructed on the surface of gold substrate with the good adsorption of template molecules.
2011, 22(6): 725-728
doi: 10.1016/j.cclet.2010.12.024
Abstract:
A novel hyperbranched conjugated chemosensor with bipyridyl groups as periphery groups(BPY-HPV)was synthesized.BPY-HPV was highly sensitive to metal ions(Cu2+, Ni2+)for the strong coordination interaction(Ksv at the order of 107 mol-1 L)monitored by fluorescence spectroscopy.Moreover, by hydrogen bonds and charge transfer interaction, BPY-HPV shows strong interaction with 1,1,2,2-tetrachloroethane whatever in CH2C12(Ksv~106 mol-1 L)or film.
A novel hyperbranched conjugated chemosensor with bipyridyl groups as periphery groups(BPY-HPV)was synthesized.BPY-HPV was highly sensitive to metal ions(Cu2+, Ni2+)for the strong coordination interaction(Ksv at the order of 107 mol-1 L)monitored by fluorescence spectroscopy.Moreover, by hydrogen bonds and charge transfer interaction, BPY-HPV shows strong interaction with 1,1,2,2-tetrachloroethane whatever in CH2C12(Ksv~106 mol-1 L)or film.
2011, 22(6): 729-732
doi: 10.1016/j.cclet.2010.12.047
Abstract:
A sensitive and convenient method for the study of electrochemical fingerprints of Chrysanthemums from different regions is studied by Belousov-Zhabotinskii(B-Z)oscillation system with malonate as a dissipative material.The results indicated that the electrochemical fingerprints of Chrysanthemums from different regions show significantly different characteristics, and can be used to identify the regions of Chrysanthemums.
A sensitive and convenient method for the study of electrochemical fingerprints of Chrysanthemums from different regions is studied by Belousov-Zhabotinskii(B-Z)oscillation system with malonate as a dissipative material.The results indicated that the electrochemical fingerprints of Chrysanthemums from different regions show significantly different characteristics, and can be used to identify the regions of Chrysanthemums.
2011, 22(6): 733-737
doi: 10.1016/j.cclet.2010.12.026
Abstract:
The application of high temperature liquid water(HTLW)to decomposition of lignin as efficient and green solution for phenolic compounds recovery was studied.Benzyl phenyl ether(BPE), the lignin model compound, was treated at temperatures ranging from 220 to 250 8C.BPE undergo hydrolysis in HTLW, and main products were phenol and benzyl alcohol with the minimum selectivities of 75.7% and 82.8%, respectively.Lower temperature led to higher selectivity in 220-250 8C temperature range.The kinetics on BPE hydrolysis was studied and the activation energy was determined as 150.3±12.5 kJ/mol with the first-order kinetic equations.Based on products distribution, the reaction mechanism for decomposition of benzyl phenyl ether was proposed.The investigated process provides insights into the design of a commercial method for utilization of lignin.
The application of high temperature liquid water(HTLW)to decomposition of lignin as efficient and green solution for phenolic compounds recovery was studied.Benzyl phenyl ether(BPE), the lignin model compound, was treated at temperatures ranging from 220 to 250 8C.BPE undergo hydrolysis in HTLW, and main products were phenol and benzyl alcohol with the minimum selectivities of 75.7% and 82.8%, respectively.Lower temperature led to higher selectivity in 220-250 8C temperature range.The kinetics on BPE hydrolysis was studied and the activation energy was determined as 150.3±12.5 kJ/mol with the first-order kinetic equations.Based on products distribution, the reaction mechanism for decomposition of benzyl phenyl ether was proposed.The investigated process provides insights into the design of a commercial method for utilization of lignin.
2011, 22(6): 738-740
doi: 10.1016/j.cclet.2010.12.048
Abstract:
Amide, which is derived from proline and is inexpensive and air-stable, has been synthesized and characterized by 1H NMR,13C NMR, and MS.It was found to be an efficient ligand in the palladium-catalyzed Suzuki cross-coupling reaction.In the Pd/amide catalytic system, aryl bromides can be coupled with phenylboronic acid in ethanol/water(1:2;v/v)in excellent yields even with a low Pd loading of 0.01 mol%.Moreover, the scope of the reaction is broad, and a wide variety of functional groups are tolerant.
Amide, which is derived from proline and is inexpensive and air-stable, has been synthesized and characterized by 1H NMR,13C NMR, and MS.It was found to be an efficient ligand in the palladium-catalyzed Suzuki cross-coupling reaction.In the Pd/amide catalytic system, aryl bromides can be coupled with phenylboronic acid in ethanol/water(1:2;v/v)in excellent yields even with a low Pd loading of 0.01 mol%.Moreover, the scope of the reaction is broad, and a wide variety of functional groups are tolerant.
2011, 22(6): 741-744
doi: 10.1016/j.cclet.2010.12.036
Abstract:
Ethylene glycol aluminum was prepared efficiently and characterized by FT-IR and NMR.It exhibited higher catalytic activity and had profitable effect than titanium glycolate and ethylene glycol antimony for the synthesis of poly(ethylene terephthalate)(PET).It was only used as polycondensation catalyst because it was sensitive to water.For this catalyst, the degree of esterification of the theoretical amount of water was produced up to 95% at 260 ℃, while the intrinsic viscosity and content of terminal carboxyl groups of the corresponding PET polyester, polymerized at 280℃, 70 Pa for 39 min, was 0.87 dL/g and 23.0 μmol/g, respectively.Ethylene glycol aluminum was a promising catalyst for the synthesis of PET polyester.
Ethylene glycol aluminum was prepared efficiently and characterized by FT-IR and NMR.It exhibited higher catalytic activity and had profitable effect than titanium glycolate and ethylene glycol antimony for the synthesis of poly(ethylene terephthalate)(PET).It was only used as polycondensation catalyst because it was sensitive to water.For this catalyst, the degree of esterification of the theoretical amount of water was produced up to 95% at 260 ℃, while the intrinsic viscosity and content of terminal carboxyl groups of the corresponding PET polyester, polymerized at 280℃, 70 Pa for 39 min, was 0.87 dL/g and 23.0 μmol/g, respectively.Ethylene glycol aluminum was a promising catalyst for the synthesis of PET polyester.
2011, 22(6): 745-748
doi: 10.1016/j.cclet.2010.12.01
Abstract:
The cloudy Silwet L-77 aqueous solution on the concentration range from 0.5% to 50% was investigated by dielectric relaxation spectroscopy.The concentration dependence of phase microstructure was confirmed by means of analyzing the dielectric parameters of bulk solution.The relaxation behavior was assigned to the interfacial polarization between the micelle and the medium, and the relaxation distribution parameter was used to figure the shape transition from sphere to ellipsoid with the concentration increasing.The synchronous reduction of permittivity and conductivity indicated the formation of the lamellar phase.As compensation, the quantity of the surfactant liquid phase gradually decreased, whose shape constantly kept ellipsoidal.
The cloudy Silwet L-77 aqueous solution on the concentration range from 0.5% to 50% was investigated by dielectric relaxation spectroscopy.The concentration dependence of phase microstructure was confirmed by means of analyzing the dielectric parameters of bulk solution.The relaxation behavior was assigned to the interfacial polarization between the micelle and the medium, and the relaxation distribution parameter was used to figure the shape transition from sphere to ellipsoid with the concentration increasing.The synchronous reduction of permittivity and conductivity indicated the formation of the lamellar phase.As compensation, the quantity of the surfactant liquid phase gradually decreased, whose shape constantly kept ellipsoidal.
2011, 22(6): 749-752
doi: 10.1016/j.cclet.2010.12.057
Abstract:
Copolymers mPEG-PCL were prepared and grafted onto polyethylenimine(PEI)to synthesize copolymers mPEG-PCL-g-PEI with low cytotoxicity.The mPEG-PCL-g-PEI could condense siRNA to form nanoparticles with positive zeta potential.These nanoparticles could delivery siRNA into cells to effectively inhibit the expression of target gene, which suggested that mPEG-PCL-g-PEl could serve as a highly efficient vector for siRNA delivery.
Copolymers mPEG-PCL were prepared and grafted onto polyethylenimine(PEI)to synthesize copolymers mPEG-PCL-g-PEI with low cytotoxicity.The mPEG-PCL-g-PEI could condense siRNA to form nanoparticles with positive zeta potential.These nanoparticles could delivery siRNA into cells to effectively inhibit the expression of target gene, which suggested that mPEG-PCL-g-PEl could serve as a highly efficient vector for siRNA delivery.
