Login In
2010 Volume 21 Issue 9
2010, 21(9): 1015-1019
doi: 10.1016/j.cclet.2010.05.024
Abstract:
Nanoparticles have properties that can be fine-tuned by their size as well as shape. Hence, there is significant current interest in preparing nano-materials of small size dispersity and to arrange them in close-packed aggregates. This letter describes a way of synthesising silver nanoparticles and their protection to aggregate by silica gel. The combination of catalytic quantities of immobilized silver nanoparticles with reductive ability of NaBH4 efficiently reduces aromatic nitroarenes to the corresponding amines in aqueous medium. Noteworthy is that highly chemoselective reactions were achieved in the presence of other functional groups such as halogen and carboxylic acid groups. The silver particles immobilized on silica gel are stable in the presence of oxygen for several months.
Nanoparticles have properties that can be fine-tuned by their size as well as shape. Hence, there is significant current interest in preparing nano-materials of small size dispersity and to arrange them in close-packed aggregates. This letter describes a way of synthesising silver nanoparticles and their protection to aggregate by silica gel. The combination of catalytic quantities of immobilized silver nanoparticles with reductive ability of NaBH4 efficiently reduces aromatic nitroarenes to the corresponding amines in aqueous medium. Noteworthy is that highly chemoselective reactions were achieved in the presence of other functional groups such as halogen and carboxylic acid groups. The silver particles immobilized on silica gel are stable in the presence of oxygen for several months.
2010, 21(9): 1020-1024
doi: 10.1016/j.cclet.2010.02.011
Abstract:
The synthesis of stearic acid triethanolamine ester over solid acid catalysts was investigated. The results showed that the catalytic activity and selectivity of zirconium sulfate supported on SBA-15(6)(pore diameter 6 nm) is better than that of commonly used hypophosphorous acid, zirconium sulfate supported on MCM-41 and zirconium sulfate supported on SBA-15(9)(pore diameter 9 nm).
The synthesis of stearic acid triethanolamine ester over solid acid catalysts was investigated. The results showed that the catalytic activity and selectivity of zirconium sulfate supported on SBA-15(6)(pore diameter 6 nm) is better than that of commonly used hypophosphorous acid, zirconium sulfate supported on MCM-41 and zirconium sulfate supported on SBA-15(9)(pore diameter 9 nm).
2010, 21(9): 1025-1028
doi: 10.1016/j.cclet.2010.05.004
Abstract:
A rapid and eco-friendly one-pot protocol for the synthesis of nitriles has been developed by treating various araldehydes bearing electron withdrawing as well as electron donating groups with hydroxylamine hydrochloride in the presence of non-toxic, non-corrosive and reusable zinc oxide(ZnO)as the catalyst under solvent-free microwave irradiation. The present approach offers the advantages of a clean reaction, simple methodology, employing readily available catalyst, short reaction duration (<1 min), high selectivity; and high yield(90-98%).
A rapid and eco-friendly one-pot protocol for the synthesis of nitriles has been developed by treating various araldehydes bearing electron withdrawing as well as electron donating groups with hydroxylamine hydrochloride in the presence of non-toxic, non-corrosive and reusable zinc oxide(ZnO)as the catalyst under solvent-free microwave irradiation. The present approach offers the advantages of a clean reaction, simple methodology, employing readily available catalyst, short reaction duration (<1 min), high selectivity; and high yield(90-98%).
2010, 21(9): 1029-1032
doi: 10.1016/j.cclet.2010.05.003
Abstract:
An efficient route for the synthesis of 5-substituted 1H-tetrazole via[2+3] cycloaddition of nitriles and sodium azide is reported using g-Fe2O3 nanoparticles as a magnetic separable catalyst. Under optimized conditions, the moderate to good yields (71-95%) can be obtained. The catalyst can be easily separated by a magnet and reused for several circles.
An efficient route for the synthesis of 5-substituted 1H-tetrazole via[2+3] cycloaddition of nitriles and sodium azide is reported using g-Fe2O3 nanoparticles as a magnetic separable catalyst. Under optimized conditions, the moderate to good yields (71-95%) can be obtained. The catalyst can be easily separated by a magnet and reused for several circles.
2010, 21(9): 1033-1036
doi: 10.1016/j.cclet.2010.04.027
Abstract:
The photopromoted carbonylation of chloroalkanes with carbon monoxide catalyzed by cobalt compounds[Co(OAc)2, CoCl2]in the presence of KI was carried out under ambient conditions. The results revealed that the catalytic activity of Co(OAc)2 was higher than that of CoCl2. A basic additive NaOAc was beneficial to the reaction. Interestingly, with NaOAc as an additive, Co(OAc)2 and COCl2 exhibited similar catalytic activity. Preliminary work showed that the role of iodide ion was initially to form active iodoalkanes via substituting chloride ion in chloroalkanes in situ, and then, the carbonylation of iodoaikanes proceeded under irradiation.
The photopromoted carbonylation of chloroalkanes with carbon monoxide catalyzed by cobalt compounds[Co(OAc)2, CoCl2]in the presence of KI was carried out under ambient conditions. The results revealed that the catalytic activity of Co(OAc)2 was higher than that of CoCl2. A basic additive NaOAc was beneficial to the reaction. Interestingly, with NaOAc as an additive, Co(OAc)2 and COCl2 exhibited similar catalytic activity. Preliminary work showed that the role of iodide ion was initially to form active iodoalkanes via substituting chloride ion in chloroalkanes in situ, and then, the carbonylation of iodoaikanes proceeded under irradiation.
2010, 21(9): 1037-1040
doi: 10.1016/j.cclet.2010.04.033
Abstract:
A series of derivatives were synthesized from trichodermin (1) which was an antifungal metabolite produced by Trichoderma taxi sp. nov. Their structures were confirmed by 1H NMR, MS spectrum. Their antifungal activities were evaluated in vitro. The preliminary structure activity relationships (SAR) results indicated that the double bond, epoxide moiety and ester group were main pharmacophore elements, the stereochemistry of C4 position played a key role as well, and the compounds 1e-1g displayed stronger antifungal activity against Magnaporthe grisea than 1.
A series of derivatives were synthesized from trichodermin (1) which was an antifungal metabolite produced by Trichoderma taxi sp. nov. Their structures were confirmed by 1H NMR, MS spectrum. Their antifungal activities were evaluated in vitro. The preliminary structure activity relationships (SAR) results indicated that the double bond, epoxide moiety and ester group were main pharmacophore elements, the stereochemistry of C4 position played a key role as well, and the compounds 1e-1g displayed stronger antifungal activity against Magnaporthe grisea than 1.
2010, 21(9): 1041-1044
doi: 10.1016/j.cclet.2010.04.011
Abstract:
The convenient one-pot method for phosphoryloxylactonization of alkenoic acids was reported:when (diacetoxyiodo) benzene, various 4-pentenoic acids and phosphates were mixed in CH3CN at room temperature, phosphoryloxylactones were obtained in good to excellent yields in short times, some had two diastereoisomers.
The convenient one-pot method for phosphoryloxylactonization of alkenoic acids was reported:when (diacetoxyiodo) benzene, various 4-pentenoic acids and phosphates were mixed in CH3CN at room temperature, phosphoryloxylactones were obtained in good to excellent yields in short times, some had two diastereoisomers.
2010, 21(9): 1049-1052
doi: 10.1016/j.cclet.2010.04.001
Abstract:
Two haptens of 3-[(5-amino-furan-2-ylmethylene) amino]oxazolidin-5-one (FZ-NH2) and 3-{[(4-carboxypbenyl) methylene]-amino}-2-oxazolidinone(CPAOZ)were synthesized. For FZ-NH2, immunogens were prepared by glutaraldehyde and diazo salt methods. For CPAOZ, immunogens were connected by the methods of the active ester and mixed acid anhydride. Compared with the combination, indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was developed with coating antigen of FZ-NH2-OVA via the glutaraldehyde method and immunogen of CPAOZ-KLH via active ester method. For furazolidone and its metabolite AOZ (NPAOZ as derivative), the sensitivities (IC50) were 2.0 μg/L and 2.5 μg/L, limits of detection (IC15) were0.09 μg/L and 0.25 μg/L, respectively. A sensitive method was developed for the simultaneous determination of furazolidone in feed and its metabolite AOZ in tissue.
Two haptens of 3-[(5-amino-furan-2-ylmethylene) amino]oxazolidin-5-one (FZ-NH2) and 3-{[(4-carboxypbenyl) methylene]-amino}-2-oxazolidinone(CPAOZ)were synthesized. For FZ-NH2, immunogens were prepared by glutaraldehyde and diazo salt methods. For CPAOZ, immunogens were connected by the methods of the active ester and mixed acid anhydride. Compared with the combination, indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was developed with coating antigen of FZ-NH2-OVA via the glutaraldehyde method and immunogen of CPAOZ-KLH via active ester method. For furazolidone and its metabolite AOZ (NPAOZ as derivative), the sensitivities (IC50) were 2.0 μg/L and 2.5 μg/L, limits of detection (IC15) were0.09 μg/L and 0.25 μg/L, respectively. A sensitive method was developed for the simultaneous determination of furazolidone in feed and its metabolite AOZ in tissue.
2010, 21(9): 1053-1056
doi: 10.1016/j.cclet.2010.03.038
Abstract:
A series of benzimidazole derivatives were synthesized expeditiously in good yields by condensation of 1, 2-diaminobenzene and aromatic aldehydes in the presence of modified scolecite catalyst. The world wide availability, easy handling and reusability of catalyst, higher yields and shorter reaction times are the advantages of the present method.
A series of benzimidazole derivatives were synthesized expeditiously in good yields by condensation of 1, 2-diaminobenzene and aromatic aldehydes in the presence of modified scolecite catalyst. The world wide availability, easy handling and reusability of catalyst, higher yields and shorter reaction times are the advantages of the present method.
2010, 21(9): 1057-1061
doi: 10.1016/j.cclet.2010.05.009
Abstract:
An efficient synthesis of symmetrical 2, 2-bis(1H-indol-3-yl)-2H-acenaphthen-1-one is achieved via a reaction of acenaphthe-nequinone and indoles catalyzed by solid superacid SO42-/TiO2 under solvent-free conditions at room temperature by grinding, which provides an efficient route to the synthesis of symmetrical 2, 2-bis(1H-indol-3-yl)-2H-acenaphthen-1-one. This procedure offers several advantages including solvent-free conditions, excellent yields of products, simple work-up as well as reuse of catalysts which makes it a useful and attractive protocol for the synthesis of these compounds.
An efficient synthesis of symmetrical 2, 2-bis(1H-indol-3-yl)-2H-acenaphthen-1-one is achieved via a reaction of acenaphthe-nequinone and indoles catalyzed by solid superacid SO42-/TiO2 under solvent-free conditions at room temperature by grinding, which provides an efficient route to the synthesis of symmetrical 2, 2-bis(1H-indol-3-yl)-2H-acenaphthen-1-one. This procedure offers several advantages including solvent-free conditions, excellent yields of products, simple work-up as well as reuse of catalysts which makes it a useful and attractive protocol for the synthesis of these compounds.
2010, 21(9): 1062-1066
doi: 10.1016/j.cclet.2010.04.025
Abstract:
Macroporous magnetic poly (GMA-EGDMA-DVB) microspheres synthesized by suspension polymerization were used as supports for palladium catalyst. The results showed the novel magnetic catalyst can promote Heck reaction of aryl halides with acrylic acid efficiently without an inert atmosphere. In addition, the novel catalyst can be conveniently recovered by applying an external magnet and reused at least five times without significant loss of its activity.
Macroporous magnetic poly (GMA-EGDMA-DVB) microspheres synthesized by suspension polymerization were used as supports for palladium catalyst. The results showed the novel magnetic catalyst can promote Heck reaction of aryl halides with acrylic acid efficiently without an inert atmosphere. In addition, the novel catalyst can be conveniently recovered by applying an external magnet and reused at least five times without significant loss of its activity.
2010, 21(9): 1067-1070
doi: 10.1016/j.cclet.2010.04.013
Abstract:
Rh nanoparticles stabilized by PEG-substituted triphenyl-phosphine (PETPP, P[C6H4-p-(OCH2CH2)nOH]3) combining double stabilization effects demonstrated high activity and good recyclability in aqueous biphasic hydrogenation of benzene. The value of turnover frequency (TOF) was 3333 h-1. Furthermore, the rhodium nanoparticle catalyst could be easily recycled for five times without loss in activity.
Rh nanoparticles stabilized by PEG-substituted triphenyl-phosphine (PETPP, P[C6H4-p-(OCH2CH2)nOH]3) combining double stabilization effects demonstrated high activity and good recyclability in aqueous biphasic hydrogenation of benzene. The value of turnover frequency (TOF) was 3333 h-1. Furthermore, the rhodium nanoparticle catalyst could be easily recycled for five times without loss in activity.
2010, 21(9): 1071-1074
doi: 10.1016/j.cclet.2010.04.004
Abstract:
A series of 1, 4-substituted phthalazine derivatives were designed and synthesized. All the prepared compounds were screened for their cytotoxic activities against A549, HT-29 and MDA-MB-231 cell lines in vitro. Among them, compounds 7a-7h showed excellent selectivity for MDA-MB-231 cell line with IC50 values from 1 nmol/L to 0.92 μmol/L. A preliminary SAR study of these derivatives was performed.
A series of 1, 4-substituted phthalazine derivatives were designed and synthesized. All the prepared compounds were screened for their cytotoxic activities against A549, HT-29 and MDA-MB-231 cell lines in vitro. Among them, compounds 7a-7h showed excellent selectivity for MDA-MB-231 cell line with IC50 values from 1 nmol/L to 0.92 μmol/L. A preliminary SAR study of these derivatives was performed.
2010, 21(9): 1075-1078
doi: 10.1016/j.cclet.2010.04.006
Abstract:
α-Aryl nitrone are one of the most useful kinds of nitrones and have been extensively explored in recent years. However, the sugar moieties have not been introduced into these molecules before. We presented here an efficient synthesis of α-aryl nitrone O-glycosides via condensation of N-substituted hydroxylamine and aryl aldehydes glycosides in benzene.
α-Aryl nitrone are one of the most useful kinds of nitrones and have been extensively explored in recent years. However, the sugar moieties have not been introduced into these molecules before. We presented here an efficient synthesis of α-aryl nitrone O-glycosides via condensation of N-substituted hydroxylamine and aryl aldehydes glycosides in benzene.
2010, 21(9): 1079-1082
doi: 10.1016/j.cclet.2010.04.041
Abstract:
A novel asymmetric alkylaminoborazine monomer, 2-propylamino-4, 6-bis (methylamino) borazine, was synthesized for the first time, and directly polymerized to give a melt-spinnable polyborazine (PBN). This asymmetric alkylaminoborazine was synthesized by an aminolysis reaction of 2, 4, 6-trichloroborazine (TCB) with different amines under mild conditions. This route turns out to be much cheaper and simpler than the conventional routes. The chemical composition, structure, molecular weights and ceramic yield were investigated by EA, FTIR, NMR, GPC and TG analysis. The PBN exhibits suitable rheological property for melt-spinning, which suggests that it is a potential precursor for BN fibers.
A novel asymmetric alkylaminoborazine monomer, 2-propylamino-4, 6-bis (methylamino) borazine, was synthesized for the first time, and directly polymerized to give a melt-spinnable polyborazine (PBN). This asymmetric alkylaminoborazine was synthesized by an aminolysis reaction of 2, 4, 6-trichloroborazine (TCB) with different amines under mild conditions. This route turns out to be much cheaper and simpler than the conventional routes. The chemical composition, structure, molecular weights and ceramic yield were investigated by EA, FTIR, NMR, GPC and TG analysis. The PBN exhibits suitable rheological property for melt-spinning, which suggests that it is a potential precursor for BN fibers.
2010, 21(9): 1083-1086
doi: 10.1016/j.cclet.2010.03.019
Abstract:
A wide variety of aldoximes and ketoximes were regenerated to corresponding carbonyl compounds with Al(NO3)3·9H2O in presence of catalytic amounts of NaBr in CH2Cl2 at room temperature.
A wide variety of aldoximes and ketoximes were regenerated to corresponding carbonyl compounds with Al(NO3)3·9H2O in presence of catalytic amounts of NaBr in CH2Cl2 at room temperature.
2010, 21(9): 1087-1090
doi: 10.1016/j.cclet.2010.04.020
Abstract:
Solasodine 11 is a steroidal alkaloid with various biological activities. Herein, 8 novel solasodine derivatives were synthesized and their effect on prostate cancer cell proliferation was assessed in vitro. Significant improvement in antiproliferative activity was achieved among some of the synthetic analogs. In particular, 19 exhibited the most potent inhibitory effect against the proliferation of PC-3 cell line (IC50=3.91 μmol/L).
Solasodine 11 is a steroidal alkaloid with various biological activities. Herein, 8 novel solasodine derivatives were synthesized and their effect on prostate cancer cell proliferation was assessed in vitro. Significant improvement in antiproliferative activity was achieved among some of the synthetic analogs. In particular, 19 exhibited the most potent inhibitory effect against the proliferation of PC-3 cell line (IC50=3.91 μmol/L).
2010, 21(9): 1091-1093
doi: 10.1016/j.cclet.2010.05.002
Abstract:
A new ent-labdane diterpenoid, 19-O-β-D-glucopyranosyl-ent-labda-8(17), 13-dien-15, 16, 19-triol, together with six known ent-labdane diterpenoids, was isolated from the aerial parts of Andrographis paniculata. The structure of the new compound was elucidated by extensive spectral analysis.
A new ent-labdane diterpenoid, 19-O-β-D-glucopyranosyl-ent-labda-8(17), 13-dien-15, 16, 19-triol, together with six known ent-labdane diterpenoids, was isolated from the aerial parts of Andrographis paniculata. The structure of the new compound was elucidated by extensive spectral analysis.
2010, 21(9): 1094-1096
doi: 10.1016/j.cclet.2010.03.031
Abstract:
Two alkyl phenols, namely, 2, 5-dimethoxy-3-undecylphenol (1) and 5-methoxy-3-undecylphenol (2), were isolated together with two known benzoquinones, 5-O-methylembelin (3) and 2-dehydroxy-5-O-methylembelin(4)from the wood of Averrhoa carambola. Their structures were elucidated on the basis of spectroscopic methods (1D and 2D NMR).
Two alkyl phenols, namely, 2, 5-dimethoxy-3-undecylphenol (1) and 5-methoxy-3-undecylphenol (2), were isolated together with two known benzoquinones, 5-O-methylembelin (3) and 2-dehydroxy-5-O-methylembelin(4)from the wood of Averrhoa carambola. Their structures were elucidated on the basis of spectroscopic methods (1D and 2D NMR).
2010, 21(9): 1097-1099
doi: 10.1016/j.cclet.2010.05.001
Abstract:
A new flavone glucoside, selagin-7-O-(6"-O-acetyl-)-β-D-glycoside, has been isolated from Cancrinia discoidea (Ledeb.) Poljak. Its structure was identified by spectroscopic methods, 2D NMR and MS. Compounds exhibited activity of anti-inflammatory in vitro.
A new flavone glucoside, selagin-7-O-(6"-O-acetyl-)-β-D-glycoside, has been isolated from Cancrinia discoidea (Ledeb.) Poljak. Its structure was identified by spectroscopic methods, 2D NMR and MS. Compounds exhibited activity of anti-inflammatory in vitro.
2010, 21(9): 1100-1102
doi: 10.1016/j.cclet.2010.04.015
Abstract:
A new sulfated triterpenoid, 3β, 24-dihydroxyurs-20-enc-24-O-sulphonyl-28-oic acid (fabagoin, 1) was isolated from the barks of Zygophyllum fabago L. Its structure was elucidated on the basis of spectroscopic data.
A new sulfated triterpenoid, 3β, 24-dihydroxyurs-20-enc-24-O-sulphonyl-28-oic acid (fabagoin, 1) was isolated from the barks of Zygophyllum fabago L. Its structure was elucidated on the basis of spectroscopic data.
2010, 21(9): 1103-1106
doi: 10.1016/j.cclet.2010.05.006
Abstract:
Two new phenylethanoid glycosides, named scroside H(1), scroside I(2), and a new secoiridoid glycoside, named picrogentioside I(3), have been isolated from the underground parts of Picrorhiza scrophulariiflora. Their structures were elucidated on the basis of spectroscopic evidence.
Two new phenylethanoid glycosides, named scroside H(1), scroside I(2), and a new secoiridoid glycoside, named picrogentioside I(3), have been isolated from the underground parts of Picrorhiza scrophulariiflora. Their structures were elucidated on the basis of spectroscopic evidence.
2010, 21(9): 1107-1110
doi: 10.1016/j.cclet.2010.05.005
Abstract:
Two new oleanane-type saponins, crotalarioside A(1)and crotalariosida B(2), were isolated from the roots of Polygala crotalarioides. Their structures were elucidated on the basis of spectroscopic and chemical evidence.
Two new oleanane-type saponins, crotalarioside A(1)and crotalariosida B(2), were isolated from the roots of Polygala crotalarioides. Their structures were elucidated on the basis of spectroscopic and chemical evidence.
2010, 21(9): 1111-1114
doi: 10.1016/j.cclet.2010.04.028
Abstract:
The selective bulk liquid membrane and polymer membrane transports of Ag (Ⅰ)from an aqueous solution containing seven metal cations, Co (Ⅱ), Ni (Ⅱ), Cu (Ⅱ), Zn (Ⅱ), Ag (Ⅰ), Cd (Ⅱ)and Pb (Ⅱ), was studied. The source phases contained equimolar concentrations of the above-mentioned cations, with the source and receiving phases being buffered at pH 5.0 and 3.0, respectively. Ag (Ⅰ) ion transport occurred with a good efficiency from the aqueous source phases across the bulk liquid membrane and polymer membrane(derived from cellulose triacetate)containing ligand 1 as the ionophores, into the aqueous receiving phases. Clear transport selectivity for Ag (Ⅰ)was observed using ligand 1. There was no selectivity for the cations using ligand 2 in the both bulk liquid membrane and polymer membrane transports.
The selective bulk liquid membrane and polymer membrane transports of Ag (Ⅰ)from an aqueous solution containing seven metal cations, Co (Ⅱ), Ni (Ⅱ), Cu (Ⅱ), Zn (Ⅱ), Ag (Ⅰ), Cd (Ⅱ)and Pb (Ⅱ), was studied. The source phases contained equimolar concentrations of the above-mentioned cations, with the source and receiving phases being buffered at pH 5.0 and 3.0, respectively. Ag (Ⅰ) ion transport occurred with a good efficiency from the aqueous source phases across the bulk liquid membrane and polymer membrane(derived from cellulose triacetate)containing ligand 1 as the ionophores, into the aqueous receiving phases. Clear transport selectivity for Ag (Ⅰ)was observed using ligand 1. There was no selectivity for the cations using ligand 2 in the both bulk liquid membrane and polymer membrane transports.
2010, 21(9): 1115-1118
doi: 10.1016/j.cclet.2010.04.026
Abstract:
We have developed a simple method for fabricating robust and low noise glass nanopore electrodes with pore size 10±5 nm to detect single molecules. β-Cyclodextrin was used as model compound for characterization. In 1.0 mol/L NaCl solution, the molecules generated current pulses of 2-5 pA with noise level less than 0.8 pA. A slide mode and a plug mode were suggested for the way of β-cyclodextrin single molecule moving into the glass nanopores.
We have developed a simple method for fabricating robust and low noise glass nanopore electrodes with pore size 10±5 nm to detect single molecules. β-Cyclodextrin was used as model compound for characterization. In 1.0 mol/L NaCl solution, the molecules generated current pulses of 2-5 pA with noise level less than 0.8 pA. A slide mode and a plug mode were suggested for the way of β-cyclodextrin single molecule moving into the glass nanopores.
2010, 21(9): 1119-1123
doi: 10.1016/j.cclet.2010.03.009
Abstract:
Porous TiO2/ZnO composite nanofibers have been successfully prepared by electrospinning technique for the first time. It was generated by calcining TiO2/ZnCl2/PVP[PVP:poly (vinyi pyrrolidone)]nanofibers, which were electrospun from a mixture solution of TiO2, ZnCl2 and PVE Transmission electron microscopy (TEM) and X-ray diffraction (XRD) analyses were used to identify the morphology of the TiO2/ZnO nanofibers and a formation of inorganic TiO2/ZnO fibers. The porous structure of the TiO2/ZnO fbers was characterized by N2 adsoption/desorption isotherm. Surface photovoltage spectroscopy (SPS) and photo-catalytic activity measurements revealed advance properties of the porous TiO2/ZnO composite nanofibers and the results were compared with pure TiO2 nanofibers, pure ZnO nanofibers and TiO2/ZnO nanoparticles.
Porous TiO2/ZnO composite nanofibers have been successfully prepared by electrospinning technique for the first time. It was generated by calcining TiO2/ZnCl2/PVP[PVP:poly (vinyi pyrrolidone)]nanofibers, which were electrospun from a mixture solution of TiO2, ZnCl2 and PVE Transmission electron microscopy (TEM) and X-ray diffraction (XRD) analyses were used to identify the morphology of the TiO2/ZnO nanofibers and a formation of inorganic TiO2/ZnO fibers. The porous structure of the TiO2/ZnO fbers was characterized by N2 adsoption/desorption isotherm. Surface photovoltage spectroscopy (SPS) and photo-catalytic activity measurements revealed advance properties of the porous TiO2/ZnO composite nanofibers and the results were compared with pure TiO2 nanofibers, pure ZnO nanofibers and TiO2/ZnO nanoparticles.
2010, 21(9): 1124-1128
doi: 10.1016/j.cclet.2010.04.029
Abstract:
A novel and simple fluorescent molecular sensor, 1-pyrenecarboxaldehyde thiosemicarbazone (Hpytsc), was synthesized. Its higher sensitivity and selectivity to mercury (Ⅱ) ion were studied through absorption and emission channels. The UV-vis spectra show that the increasing mercury (Ⅱ) ion concentrations result in the decreasing absorption intensity. The fluorescence monomer emission of Hpytsc is enhanced upon binding mercury (Ⅱ) ion, which should be due to the 1:1 complex formation between Hpytsc and metal ion.
A novel and simple fluorescent molecular sensor, 1-pyrenecarboxaldehyde thiosemicarbazone (Hpytsc), was synthesized. Its higher sensitivity and selectivity to mercury (Ⅱ) ion were studied through absorption and emission channels. The UV-vis spectra show that the increasing mercury (Ⅱ) ion concentrations result in the decreasing absorption intensity. The fluorescence monomer emission of Hpytsc is enhanced upon binding mercury (Ⅱ) ion, which should be due to the 1:1 complex formation between Hpytsc and metal ion.
2010, 21(9): 1129-1132
doi: 10.1016/j.cclet.2010.04.002
Abstract:
We report for the first time a cleavage phenomenon in the resonant peak of a piezoelectric quartz crystal(PQC)in liquid phase. In the presence of a strong longitudinal wave effect, an additional resonant peak appears in the conductance-frequency curve. With gradually increasing liquid density, the additional peak moves from low to high frequency region then disappears. The frequency of the additional resonant peak is sensitive to the change in liquid density. The frequency shift of the additional peak is linear with the liquid density in a given range. For a 5 MHz PQC with a reflection distance of 16 mm for longitudinal wave, the sensitivity to liquid density is 2.61×106 Hz g-1 cm3. The overlap between the primary resonant peak and the additional resonant peak causes a decrease in the intensity of the former and an increase in the intensity of the latter. In a combined impedance analysis method, the changes in surface mass loading, density and viscosity of the liquid were monitored simultaneously by a PQC sensor.
We report for the first time a cleavage phenomenon in the resonant peak of a piezoelectric quartz crystal(PQC)in liquid phase. In the presence of a strong longitudinal wave effect, an additional resonant peak appears in the conductance-frequency curve. With gradually increasing liquid density, the additional peak moves from low to high frequency region then disappears. The frequency of the additional resonant peak is sensitive to the change in liquid density. The frequency shift of the additional peak is linear with the liquid density in a given range. For a 5 MHz PQC with a reflection distance of 16 mm for longitudinal wave, the sensitivity to liquid density is 2.61×106 Hz g-1 cm3. The overlap between the primary resonant peak and the additional resonant peak causes a decrease in the intensity of the former and an increase in the intensity of the latter. In a combined impedance analysis method, the changes in surface mass loading, density and viscosity of the liquid were monitored simultaneously by a PQC sensor.
2010, 21(9): 1133-1136
doi: 10.1016/j.cclet.2010.04.003
Abstract:
The present study describes guanidinium-based ionic liquids (GBILs) as stationary phases for capillary gas chromatography (CGC) and to the best of our knowledge, no related reports are available up to now. In this study, a hexaalkylguanidinium ionic liquid (DOTMG-NTf2) was synthesized and coated statically onto capillary columns. Selectivity of the stationary phase was evaluated by separating Grob test mixture, test mixture, alcohols mixture, and fatty acid methyl esters mixture, and thermal stability was investigated as well. The present study demonstrates that GBILs as CGC stationary phases exhibit satisfactory selectivity and thermal stability and have a great potential as new candidates for CGC stationary phases.
The present study describes guanidinium-based ionic liquids (GBILs) as stationary phases for capillary gas chromatography (CGC) and to the best of our knowledge, no related reports are available up to now. In this study, a hexaalkylguanidinium ionic liquid (DOTMG-NTf2) was synthesized and coated statically onto capillary columns. Selectivity of the stationary phase was evaluated by separating Grob test mixture, test mixture, alcohols mixture, and fatty acid methyl esters mixture, and thermal stability was investigated as well. The present study demonstrates that GBILs as CGC stationary phases exhibit satisfactory selectivity and thermal stability and have a great potential as new candidates for CGC stationary phases.
2010, 21(9): 1137-1140
doi: 10.1016/j.cclet.2010.04.014
Abstract:
A novel low temperature method was used to prepare the mesoporous carbon (MC) counter electrode (CE) on indium-doped tin oxide coated polyethylene naphthalate (ITO-PEN) for flexible dye-sensitized solar cells (DSSCs). The obtained flexible MC CEs with carbon loading of 280 μg cm-2 were characterized by SEM, XRD and electrochemical impedance. The light-to-electricity conversion efficiency of the DSSC fabricated with the prepared flexible MC CE was 86% of that of DSSC based on the decomposited Pt CE.
A novel low temperature method was used to prepare the mesoporous carbon (MC) counter electrode (CE) on indium-doped tin oxide coated polyethylene naphthalate (ITO-PEN) for flexible dye-sensitized solar cells (DSSCs). The obtained flexible MC CEs with carbon loading of 280 μg cm-2 were characterized by SEM, XRD and electrochemical impedance. The light-to-electricity conversion efficiency of the DSSC fabricated with the prepared flexible MC CE was 86% of that of DSSC based on the decomposited Pt CE.
2010, 21(9): 1945-1048
doi: 10.1016/j.cclet.2010.03.018
Abstract:
A series of some new 2-imino-5-[(Z)-1-(4-methylphenyl) methylidene]-3-[5-(2-oxo-2H-3-chromenyl)-1, 3-oxazol-2-yl]-1, 3-thiazolan-4-ones 5a-j has been synthesized and assayed for their antibacterial activity against Gram-positive bacteria viz. Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 6538p) and Micrococcus luteus (IFC 12708), and Gram-negative bacteria viz. Proteus vulgaris(ATCC 3851), Salmonella typhimurium(ATCC 14028) and Escherichia coli(ATCC 25922). Among the screened compounds, 5d, 5e, 5f, 5g, and 5j exhibited potent inhibitory activity compared to standard drug, and emerged as potential molecules for further development.
A series of some new 2-imino-5-[(Z)-1-(4-methylphenyl) methylidene]-3-[5-(2-oxo-2H-3-chromenyl)-1, 3-oxazol-2-yl]-1, 3-thiazolan-4-ones 5a-j has been synthesized and assayed for their antibacterial activity against Gram-positive bacteria viz. Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 6538p) and Micrococcus luteus (IFC 12708), and Gram-negative bacteria viz. Proteus vulgaris(ATCC 3851), Salmonella typhimurium(ATCC 14028) and Escherichia coli(ATCC 25922). Among the screened compounds, 5d, 5e, 5f, 5g, and 5j exhibited potent inhibitory activity compared to standard drug, and emerged as potential molecules for further development.
