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2005 Volume 16 Issue 5
2005, 16(5): 569-571
Abstract:
A facile synthetic route to two seco-eudesmane, 4, 5-dioxo-10-epi-4, 5-seco-γeudesmane (1) and 4, 5-dioxo-10-epi-4, 5-seco-γ-eudesmol (2) from (+)-dihydrocarvone has been described. Avoiding expensive reagents, this highly economic method especially suits for the synthesis of 4, 5-seco-eudesman-type and ophianon-type sesquiterpenes with a double bond at position 11 and 12.
A facile synthetic route to two seco-eudesmane, 4, 5-dioxo-10-epi-4, 5-seco-γeudesmane (1) and 4, 5-dioxo-10-epi-4, 5-seco-γ-eudesmol (2) from (+)-dihydrocarvone has been described. Avoiding expensive reagents, this highly economic method especially suits for the synthesis of 4, 5-seco-eudesman-type and ophianon-type sesquiterpenes with a double bond at position 11 and 12.
2005, 16(5): 572-574
Abstract:
A new cyclic carbonate, 2,2-ethylenedioxypropane-1,3-diol carbonate (EOPDC), was synthesized through a two-step reaction from dihydroxyacetone dimer, and polymerized in bulk initiated by Sn(Oct)2 to give a high molecular weight polycarbonate. The structure of monomer and the polymer were characterized by FT-IR, 1H NMR, 13C NMR. The cytotoxicity of the obtained polycarbonate was investigated by MTT assay.
A new cyclic carbonate, 2,2-ethylenedioxypropane-1,3-diol carbonate (EOPDC), was synthesized through a two-step reaction from dihydroxyacetone dimer, and polymerized in bulk initiated by Sn(Oct)2 to give a high molecular weight polycarbonate. The structure of monomer and the polymer were characterized by FT-IR, 1H NMR, 13C NMR. The cytotoxicity of the obtained polycarbonate was investigated by MTT assay.
2005, 16(5): 575-578
Abstract:
Photochemically promoted Diels-Alder reactions of 1, 4-diaryl-1-azabutadienes with2,3-dihydrofuran were achieved by using 2, 4, 6-triphenylpyrylium tetrafluoroborate as catalyst to produce corresponding styrylfuroquinolines in high yield.
Photochemically promoted Diels-Alder reactions of 1, 4-diaryl-1-azabutadienes with2,3-dihydrofuran were achieved by using 2, 4, 6-triphenylpyrylium tetrafluoroborate as catalyst to produce corresponding styrylfuroquinolines in high yield.
2005, 16(5): 579-582
Abstract:
Sustained oscillations were observed in the BrO3--fructose-Mn2+-H2SO4 system.Unlike the classical BZ oscillations, the present oscillations might be considered as radicalcontrolled rather than bromide-controlled since no substance subjected to bromination was present.Addition of acetone induced dual-frequency oscillations comprised of both the radical-controlled and the bromide-controlled oscillations.
Sustained oscillations were observed in the BrO3--fructose-Mn2+-H2SO4 system.Unlike the classical BZ oscillations, the present oscillations might be considered as radicalcontrolled rather than bromide-controlled since no substance subjected to bromination was present.Addition of acetone induced dual-frequency oscillations comprised of both the radical-controlled and the bromide-controlled oscillations.
2005, 16(5): 583-584
Abstract:
The solid-phase preparation of vinyl sulfones via a novel polystyrene-supported selenomethyl phenyl sulfone reagent has been reported.
The solid-phase preparation of vinyl sulfones via a novel polystyrene-supported selenomethyl phenyl sulfone reagent has been reported.
2005, 16(5): 585-588
Abstract:
Peptide nucleic acids (PNA) oligomers were synthesized in most cases by peptide synthesis from N-protected monomers. In this work a new method of obtaining PNA monomer by Ugi four-component condensation reaction was tested by solid-phase synthesis. The Fmoc protected PNA monomer was build up with thymin-1-yl acetic acid, 3-methylbutyl aldehyde, Fmoc protected aminoethyl isocyanide and Gly-Wang resin.
Peptide nucleic acids (PNA) oligomers were synthesized in most cases by peptide synthesis from N-protected monomers. In this work a new method of obtaining PNA monomer by Ugi four-component condensation reaction was tested by solid-phase synthesis. The Fmoc protected PNA monomer was build up with thymin-1-yl acetic acid, 3-methylbutyl aldehyde, Fmoc protected aminoethyl isocyanide and Gly-Wang resin.
2005, 16(5): 589-592
Abstract:
The nucleophilic addition of Ti(Ⅳ) enolate derived from methyl aryl ketones to α, β-unsaturated compounds was found to be highly selective to give 1, 2 addition products.
The nucleophilic addition of Ti(Ⅳ) enolate derived from methyl aryl ketones to α, β-unsaturated compounds was found to be highly selective to give 1, 2 addition products.
2005, 16(5): 593-596
Abstract:
Using thioglycosides as donors, trimethylsilyl trifluoromethanesulfonate (TMSOTf) and N-iodosuccinimide(NIS) as promoter, a modified procedure for the glycosylation of spirostanol was developed. A series of saponins were synthesized in mild condition with excellent yields.
Using thioglycosides as donors, trimethylsilyl trifluoromethanesulfonate (TMSOTf) and N-iodosuccinimide(NIS) as promoter, a modified procedure for the glycosylation of spirostanol was developed. A series of saponins were synthesized in mild condition with excellent yields.
2005, 16(5): 597-600
Abstract:
Two new symmetric chromophores:2, 8-bis-[(2-4'-ethoxy phenyl-5-4'-styryl)-1, 3, 4-oxadiazole] didibenzothiophene (abbreviated as SO-G1) and 2, 8-bis-[(2-4'-ethoxy phenyl-5-4'-styryl)-1, 3, 4-oxadiazole]-N-ethyl carbazole (abbreviated as NO-G1) have been synthesized and characterized. Both chromophores exhibit strong two-photon absorption (TPA) with the cross-sections of 2.99×10-48 and 3.48×10-48 cm4·s·photon-1 in THF and large up-conversion emission, when pumped by Ti:sapphire femto-second laser at 720 nm.
Two new symmetric chromophores:2, 8-bis-[(2-4'-ethoxy phenyl-5-4'-styryl)-1, 3, 4-oxadiazole] didibenzothiophene (abbreviated as SO-G1) and 2, 8-bis-[(2-4'-ethoxy phenyl-5-4'-styryl)-1, 3, 4-oxadiazole]-N-ethyl carbazole (abbreviated as NO-G1) have been synthesized and characterized. Both chromophores exhibit strong two-photon absorption (TPA) with the cross-sections of 2.99×10-48 and 3.48×10-48 cm4·s·photon-1 in THF and large up-conversion emission, when pumped by Ti:sapphire femto-second laser at 720 nm.
2005, 16(5): 601-603
Abstract:
A novel macrolactonization method was developed using a chiral β-lactam as the template. This novel method features that the macrocyclization is simultaneously achieved while a TBS protected hydroxy group is deprotected.
A novel macrolactonization method was developed using a chiral β-lactam as the template. This novel method features that the macrocyclization is simultaneously achieved while a TBS protected hydroxy group is deprotected.
2005, 16(5): 604-606
Abstract:
24-Methylenecholest-5-ene-7-oxo-3β,19-diacetate 5 was synthesized starting from stigmasterol via twelve step reactions in 4.1% overall yield. It can be served as a key intermediate for the synthesis of 24-methylenecholest-5-ene-3β,7β,19-triol 1, a naturally occuring polyhydroxylated sterol with potential biological activity.
24-Methylenecholest-5-ene-7-oxo-3β,19-diacetate 5 was synthesized starting from stigmasterol via twelve step reactions in 4.1% overall yield. It can be served as a key intermediate for the synthesis of 24-methylenecholest-5-ene-3β,7β,19-triol 1, a naturally occuring polyhydroxylated sterol with potential biological activity.
2005, 16(5): 607-608
Abstract:
An rapid and efficient synthesis of 2, 4, 6-triarylpyridines is reported using substituted benzaldehydes, substituted acetophenones and ammonia as starting materials under microwave irradiation in the presence of PEG-400.
An rapid and efficient synthesis of 2, 4, 6-triarylpyridines is reported using substituted benzaldehydes, substituted acetophenones and ammonia as starting materials under microwave irradiation in the presence of PEG-400.
2005, 16(5): 609-612
Abstract:
Several thiourea polymers have been synthesized through the reaction of diamine with 1,4- or 1, 3- benzenedicarbonyl chloride and ammonium thiocyanate by solid-liquid phase transfer catalysis of polyethylene glycol-400 (PEG-400). The polymers were characterized and identified by elemental analysis, IR, 1HNMR and GPC. The multifunctional polymers have potential value as an ideal support for immobilized enzymes.
Several thiourea polymers have been synthesized through the reaction of diamine with 1,4- or 1, 3- benzenedicarbonyl chloride and ammonium thiocyanate by solid-liquid phase transfer catalysis of polyethylene glycol-400 (PEG-400). The polymers were characterized and identified by elemental analysis, IR, 1HNMR and GPC. The multifunctional polymers have potential value as an ideal support for immobilized enzymes.
2005, 16(5): 613-615
Abstract:
A new compound, named (S)-α-acetylamino-β-(3-indole)propanol (1) was isolated, along with two known compounds teleocidin B1 and emycin B from culture broth of a streptomycete strain YIM33176 (streptomyces pleomorphus). The structure of 1 was determined by detailed spectroscopic investigation.
A new compound, named (S)-α-acetylamino-β-(3-indole)propanol (1) was isolated, along with two known compounds teleocidin B1 and emycin B from culture broth of a streptomycete strain YIM33176 (streptomyces pleomorphus). The structure of 1 was determined by detailed spectroscopic investigation.
2005, 16(5): 616-618
Abstract:
A novel triterpenoid, D:B-friedoursane-3α, 16α-dihydroxy-7α, 8α-epoxy-5(10)-ene,named petatrichol A, was isolated from the roots of Petasites tricholobus Franch.. Its structure was elucidated by spectroscopic methods, especially 2DNMR techniques.
A novel triterpenoid, D:B-friedoursane-3α, 16α-dihydroxy-7α, 8α-epoxy-5(10)-ene,named petatrichol A, was isolated from the roots of Petasites tricholobus Franch.. Its structure was elucidated by spectroscopic methods, especially 2DNMR techniques.
2005, 16(5): 619-622
Abstract:
A new asterosaponin named novaeguinoside A, along with a known saponin, asteronyl pentaglycoside sulfate, was isolated from the starfish Culcita novaeguineae. The new compound was identified to be sodium 6α-O-{β-D-fucopyranosyl-(1→2)-β-D-fucopyranosyl-(1→4)-[β-Dquinovopyranosy1-(1→2)]-β-D-xylopyranosy1-(1→3)-β-D-quinovopyranosy1}-5α-pregn-9(11)-en-20-one-3β-yl-sulfate by extensive spectral analysis and chemical evidence.
A new asterosaponin named novaeguinoside A, along with a known saponin, asteronyl pentaglycoside sulfate, was isolated from the starfish Culcita novaeguineae. The new compound was identified to be sodium 6α-O-{β-D-fucopyranosyl-(1→2)-β-D-fucopyranosyl-(1→4)-[β-Dquinovopyranosy1-(1→2)]-β-D-xylopyranosy1-(1→3)-β-D-quinovopyranosy1}-5α-pregn-9(11)-en-20-one-3β-yl-sulfate by extensive spectral analysis and chemical evidence.
2005, 16(5): 623-624
Abstract:
Two new xanthones, 1, 6, 8-trihydroxy-2, 3-methylenedioxyxanthone 1 and 1, 4-dihydroxy-6, 7-methylenedioxyxanthone 2, were isolated from the roots of Polygala crotalarioides.Their structures were elucidated by spectroscopic and chemical methods.
Two new xanthones, 1, 6, 8-trihydroxy-2, 3-methylenedioxyxanthone 1 and 1, 4-dihydroxy-6, 7-methylenedioxyxanthone 2, were isolated from the roots of Polygala crotalarioides.Their structures were elucidated by spectroscopic and chemical methods.
2005, 16(5): 625-626
Abstract:
Two new ent-kaurenoids, 19-acetyl-ent-3β, 17-dihydroxykaur-15-ene(1), 19-acetyl-ent-3β-hydroxykaur-15-en-17-al (2) were isolated from Cacalia pilgeriana. Their structures were elucidated by spectroscopic methods.
Two new ent-kaurenoids, 19-acetyl-ent-3β, 17-dihydroxykaur-15-ene(1), 19-acetyl-ent-3β-hydroxykaur-15-en-17-al (2) were isolated from Cacalia pilgeriana. Their structures were elucidated by spectroscopic methods.
2005, 16(5): 627-630
Abstract:
A method has been presented for the simultaneous analysis of neurotoxin β-N-oxalyl-α,β-diaminopropionic acid (β-ODAP) and its non-or low-toxic isomer α-ODAP as well as other amino acids in Lathyrus sativus extracts after derivatization with para-nitrobenzyloxycarbonyl chloride (PNZ-C1) by reversed-phase (C18 column) high performance liquid chromatography(RP-HPLC). Detection limits of isomers were 0.08 μg/mL for both β-, α-ODAP, for homoarginine 0.09 μg/mL at a signal-to-noise ratio of 3:1.
A method has been presented for the simultaneous analysis of neurotoxin β-N-oxalyl-α,β-diaminopropionic acid (β-ODAP) and its non-or low-toxic isomer α-ODAP as well as other amino acids in Lathyrus sativus extracts after derivatization with para-nitrobenzyloxycarbonyl chloride (PNZ-C1) by reversed-phase (C18 column) high performance liquid chromatography(RP-HPLC). Detection limits of isomers were 0.08 μg/mL for both β-, α-ODAP, for homoarginine 0.09 μg/mL at a signal-to-noise ratio of 3:1.
2005, 16(5): 631-634
Abstract:
A new luminescent europium complex[Eu(DBM)3dpq] (DBM=1, 3-diphenyl-1, 3-propanedionate and dpq=dipyrido[2,3-f] [2',3'-h]quinoxaline) has been synthesized and shows intense red emission under UV excitation. With the device structure ITO/TPD/Eu(DBM)3dpq:TPD (1:2)/Gd(DBM)3bath/Mg:Ag, sharp-band red emissions with low turn-on voltage of 3V and high brightness of 304cd m-2 were achieved.
A new luminescent europium complex[Eu(DBM)3dpq] (DBM=1, 3-diphenyl-1, 3-propanedionate and dpq=dipyrido[2,3-f] [2',3'-h]quinoxaline) has been synthesized and shows intense red emission under UV excitation. With the device structure ITO/TPD/Eu(DBM)3dpq:TPD (1:2)/Gd(DBM)3bath/Mg:Ag, sharp-band red emissions with low turn-on voltage of 3V and high brightness of 304cd m-2 were achieved.
2005, 16(5): 635-638
Abstract:
A novel nano crystalline Ag2O2-PbO2 film chemically modified electrode (CME) was prepared and the CME was characterized by X-ray diffractometer (XRD) and atomic force microscope (AFM). By chronoamperometry, the nano Ag2O2-PbO2 CME was used as bioelectrochemical sensor to determine the population of Escherichia coli (E. coli) in water. Compared with conventional methods, it is found that the technique we used is fast and convenient in counting E.coli.
A novel nano crystalline Ag2O2-PbO2 film chemically modified electrode (CME) was prepared and the CME was characterized by X-ray diffractometer (XRD) and atomic force microscope (AFM). By chronoamperometry, the nano Ag2O2-PbO2 CME was used as bioelectrochemical sensor to determine the population of Escherichia coli (E. coli) in water. Compared with conventional methods, it is found that the technique we used is fast and convenient in counting E.coli.
2005, 16(5): 639-642
Abstract:
An assay is presented for simultaneously determining 5 biogenic amines and the major non-protein amino acids:the toxin β-N-oxalyl-L-α,β-diaminopropanoic acid (β-ODAP), its isomer α-ODAP and homoarginine in Lathyrus sativus extracts using the HPLC system after derivatization with para-nitrobenzyloxycarbonyl chloride (PNZ-C1). However, it is more worthy of noting that this paper also describes a new extraction method using 0.2 mol/L HC1O4. The new method has some advantages:shorter extraction-time, simultaneous extraction of free amino acids and polyamines, better inhibiting the isomerization of β-ODAP to α-ODAP, and so on.
An assay is presented for simultaneously determining 5 biogenic amines and the major non-protein amino acids:the toxin β-N-oxalyl-L-α,β-diaminopropanoic acid (β-ODAP), its isomer α-ODAP and homoarginine in Lathyrus sativus extracts using the HPLC system after derivatization with para-nitrobenzyloxycarbonyl chloride (PNZ-C1). However, it is more worthy of noting that this paper also describes a new extraction method using 0.2 mol/L HC1O4. The new method has some advantages:shorter extraction-time, simultaneous extraction of free amino acids and polyamines, better inhibiting the isomerization of β-ODAP to α-ODAP, and so on.
2005, 16(5): 643-646
Abstract:
The full scan ESI/MS and ESI/MS2 of N-(O, O-diisopropyl) phosphoryl aromatic amino acids (DIPPAAAs), N-(O, O-diisopropyl) phosphoryl phenylalanine, N-(O, O-diisopropyl)phosphoryl tryptophan and N-(O, O-diisopropyl) phosphoryl tyrosine, were obtained. The specific ions for them were found. Their stability in the LC mobile phase was investigated using developed HPLC/UV/ESI/MS and the results demonstrated that the DIPPAAAs were stable in the mobile phase (5 mmol/L NH4Ac-MeCN (80:20,v/v, pH7.5) within 48 h.
The full scan ESI/MS and ESI/MS2 of N-(O, O-diisopropyl) phosphoryl aromatic amino acids (DIPPAAAs), N-(O, O-diisopropyl) phosphoryl phenylalanine, N-(O, O-diisopropyl)phosphoryl tryptophan and N-(O, O-diisopropyl) phosphoryl tyrosine, were obtained. The specific ions for them were found. Their stability in the LC mobile phase was investigated using developed HPLC/UV/ESI/MS and the results demonstrated that the DIPPAAAs were stable in the mobile phase (5 mmol/L NH4Ac-MeCN (80:20,v/v, pH7.5) within 48 h.
2005, 16(5): 647-650
Abstract:
The interactions between granulocyte-colony stimulating factor (G-CSF) and dextran sulfate/κ-carrageenan oligosa1ccharide were studied by capillary zone electrophoresis. Dextran sulfate could strongly interact with G-CSF and the complex was detected. The binding constant and stoichiometry were determined to be 1.2×106 (mol/L)-1 and 3:1, respectively. However, the interaction between κ-carrageenan oligosaccharide and G-CSF was not found.
The interactions between granulocyte-colony stimulating factor (G-CSF) and dextran sulfate/κ-carrageenan oligosa1ccharide were studied by capillary zone electrophoresis. Dextran sulfate could strongly interact with G-CSF and the complex was detected. The binding constant and stoichiometry were determined to be 1.2×106 (mol/L)-1 and 3:1, respectively. However, the interaction between κ-carrageenan oligosaccharide and G-CSF was not found.
2005, 16(5): 651-654
Abstract:
The double-stranded DNA (dsDNA) probe contains two different protein binding sites.One is for DNA-binding proteins to be detected and the other is for a DNA restriction enzyme.The two sites were arranged together with no base interval. The working principle of the capturing dsDNA probe is described as follows:the capturing probe can be cut with the DNA restriction enzyme (such as EcoR I) to cause a sticky terminal, if the probe is not bound with a target protein, and the sticky terminal can be extended and labeled with Cy3-dUTP by DNA polymerase. When the probe is bound with a target protein, the probe is not capable to be cut by the restriction enzyme because of space obstruction. The amount of the target DNA binding proteins can be measured according to the variations of fluorescent signals of the corresponding probes.
The double-stranded DNA (dsDNA) probe contains two different protein binding sites.One is for DNA-binding proteins to be detected and the other is for a DNA restriction enzyme.The two sites were arranged together with no base interval. The working principle of the capturing dsDNA probe is described as follows:the capturing probe can be cut with the DNA restriction enzyme (such as EcoR I) to cause a sticky terminal, if the probe is not bound with a target protein, and the sticky terminal can be extended and labeled with Cy3-dUTP by DNA polymerase. When the probe is bound with a target protein, the probe is not capable to be cut by the restriction enzyme because of space obstruction. The amount of the target DNA binding proteins can be measured according to the variations of fluorescent signals of the corresponding probes.
2005, 16(5): 655-658
Abstract:
The electrooxidation behavior of 3, 3' 5, 5'-tetramethylbenzidine(TMB) was investigated using a platinum minigrid optically transparent thin-layer spectroelectrochemical cell. TMB underwent one two-electron electrooxidation process to yield quinonediimine in the pH range from 2.0 to < 4.0, and two consecutive one-electron electrooxidation processes, gave the mediate product free radical of TMB first, then gave the oxidation product quinonediimine in the pH range from 4.0 to < 7.0. In the pH range from 7.0 to 10.0, the electrooxidation of TMB was also one two-electron electrooxidation process to yield an azo compound. The formal potential E0' and the electron transfer number of the electrooxidation of TMB at pH 2.0 and pH 8.4 were determined by spectroelectrochemical techniques.
The electrooxidation behavior of 3, 3' 5, 5'-tetramethylbenzidine(TMB) was investigated using a platinum minigrid optically transparent thin-layer spectroelectrochemical cell. TMB underwent one two-electron electrooxidation process to yield quinonediimine in the pH range from 2.0 to < 4.0, and two consecutive one-electron electrooxidation processes, gave the mediate product free radical of TMB first, then gave the oxidation product quinonediimine in the pH range from 4.0 to < 7.0. In the pH range from 7.0 to 10.0, the electrooxidation of TMB was also one two-electron electrooxidation process to yield an azo compound. The formal potential E0' and the electron transfer number of the electrooxidation of TMB at pH 2.0 and pH 8.4 were determined by spectroelectrochemical techniques.
2005, 16(5): 659-662
Abstract:
We have investigated the use of flash evaporation, headspace solid-phase microextraction (HS-SPME) and steam distillation (SD) as sample concentration and preparation techniques for the analysis of volatile constituents present in Houttuynia cordata Thunb. The samples were analyzed by gas chromatography (GC) and identified by mass spectrometry (MS).Comparison studies were performed. It was found that the results obtained between Headspace solid-phase microextraction HS-SPME and SD techniques were in good agreement. Seventy-nine compounds in Houttuynia cordata Thunb were identified by MS. In flash evaporation, thirty-nine compounds were identified. Discrimination in the response for many constituents studied was not observed, which can be clearly observed in SD and HS-SPME techniques. As a conclusion,HS-SPME is a powerful tool for determining the volatile constitutes present in the Houttuynia cordata.
We have investigated the use of flash evaporation, headspace solid-phase microextraction (HS-SPME) and steam distillation (SD) as sample concentration and preparation techniques for the analysis of volatile constituents present in Houttuynia cordata Thunb. The samples were analyzed by gas chromatography (GC) and identified by mass spectrometry (MS).Comparison studies were performed. It was found that the results obtained between Headspace solid-phase microextraction HS-SPME and SD techniques were in good agreement. Seventy-nine compounds in Houttuynia cordata Thunb were identified by MS. In flash evaporation, thirty-nine compounds were identified. Discrimination in the response for many constituents studied was not observed, which can be clearly observed in SD and HS-SPME techniques. As a conclusion,HS-SPME is a powerful tool for determining the volatile constitutes present in the Houttuynia cordata.
2005, 16(5): 663-666
Abstract:
A novel coordination polymer[Ag(pyta)]n (pyta-=4-pyridylthioacetate) containing bound thioether sulfurs and single-stranded helical chains has been synthesized and structurally characterized.
A novel coordination polymer[Ag(pyta)]n (pyta-=4-pyridylthioacetate) containing bound thioether sulfurs and single-stranded helical chains has been synthesized and structurally characterized.
2005, 16(5): 667-670
Abstract:
The photocatalytic degradation of polyvinyl chloride (PVC) films by tungstophosphoric acid (HPW) was investigated. The main reason for highly enhanced photodegradation of HPW-doped PVC film was studied and discussed.
The photocatalytic degradation of polyvinyl chloride (PVC) films by tungstophosphoric acid (HPW) was investigated. The main reason for highly enhanced photodegradation of HPW-doped PVC film was studied and discussed.
2005, 16(5): 671-674
Abstract:
A novel organosilane, N-n-butyl-γ-aminopropylmethyldimethoxysilane was synthesized through aminization reaction and the chemical structure of resulting products was characterized by 1HNMR, 13CNMR, FT-IR and elemental analysis. The results of test on probation for this organosilane proved that it was effective to modify surface-paintability of organosiloxane sealants.
A novel organosilane, N-n-butyl-γ-aminopropylmethyldimethoxysilane was synthesized through aminization reaction and the chemical structure of resulting products was characterized by 1HNMR, 13CNMR, FT-IR and elemental analysis. The results of test on probation for this organosilane proved that it was effective to modify surface-paintability of organosiloxane sealants.
2005, 16(5): 675-676
Abstract:
Novel thermosensitive hydrogels based on polymerization of N-isopropyl acrylamide,Sodium acrylate, and diacetone acrylamide were synthesized. The swelling ratio and dynamic swelling were investigated. The results indicated that the hydrogels exhibited high water uptake and themosensitivity. The swelling properties and volume phase transition temperature could be adjusted by contents of the comonomers in the gels.
Novel thermosensitive hydrogels based on polymerization of N-isopropyl acrylamide,Sodium acrylate, and diacetone acrylamide were synthesized. The swelling ratio and dynamic swelling were investigated. The results indicated that the hydrogels exhibited high water uptake and themosensitivity. The swelling properties and volume phase transition temperature could be adjusted by contents of the comonomers in the gels.
2005, 16(5): 677-680
Abstract:
A series of novel rhenium(Ⅰ) 2,2'-bipyridyl complexes[fac-Re(4,4'-di-COOEt-bpy)-(CO)3(Xpy)PF6], where bpy is 2,2'-bipyridine, py is pyridine and X is 3-methyl, 3-hydroxy, or3-amino, were synthesized, their photophysical and electrochemical properties were studied. The Re(Ⅱ/Ⅰ) oxidation potentials decreased as the X group becomes more electron donating from H to3-methyl, 3-hydroxy, or 3-amino, which might be a very convenient ways for adjusting the electron transfer driving force.
A series of novel rhenium(Ⅰ) 2,2'-bipyridyl complexes[fac-Re(4,4'-di-COOEt-bpy)-(CO)3(Xpy)PF6], where bpy is 2,2'-bipyridine, py is pyridine and X is 3-methyl, 3-hydroxy, or3-amino, were synthesized, their photophysical and electrochemical properties were studied. The Re(Ⅱ/Ⅰ) oxidation potentials decreased as the X group becomes more electron donating from H to3-methyl, 3-hydroxy, or 3-amino, which might be a very convenient ways for adjusting the electron transfer driving force.
2005, 16(5): 681-684
Abstract:
The spontaneous formation of vesicles in the aqueous of cationic surfactant phosphate(PTA) and anionic surfactant sodium dodecyl sulfate (SDS) at certain mixing ratios have obtained1.The addition of urea or NaI will expand the range of spontaneous vesicle formation. The fact is demonstrated by negative-staining transmission electron microscope(TEM) and dynamic light scattering(DLS) methods. The phenomenon especially in the part of urea is reported by us at first.Mechanism of urea/NaI-induced vesicles formation is discussed from the viewpoint of the molecular geometry packing parameter f, conformation and interaction.
The spontaneous formation of vesicles in the aqueous of cationic surfactant phosphate(PTA) and anionic surfactant sodium dodecyl sulfate (SDS) at certain mixing ratios have obtained1.The addition of urea or NaI will expand the range of spontaneous vesicle formation. The fact is demonstrated by negative-staining transmission electron microscope(TEM) and dynamic light scattering(DLS) methods. The phenomenon especially in the part of urea is reported by us at first.Mechanism of urea/NaI-induced vesicles formation is discussed from the viewpoint of the molecular geometry packing parameter f, conformation and interaction.
2005, 16(5): 685-687
Abstract:
Photoinduced synthesis of CO2 and CH4 was investigated using a batch reaction system on several photoactive materials supported on silicon dioxide. Single semiconductor showed higher selectivity to C1 compounds. The production of C2-C3 oxygenates took place preferentially on composite semiconductor photocatalysts. In particular, it was found that acetone was the primary product over Cu/CdS-TiO2 /SiO2.
Photoinduced synthesis of CO2 and CH4 was investigated using a batch reaction system on several photoactive materials supported on silicon dioxide. Single semiconductor showed higher selectivity to C1 compounds. The production of C2-C3 oxygenates took place preferentially on composite semiconductor photocatalysts. In particular, it was found that acetone was the primary product over Cu/CdS-TiO2 /SiO2.
2005, 16(5): 688-690
Abstract:
Molecular dynamics (MD) simulation are used to study the properties of gemini surfactant of ethyl-α,ω-bis(dodecyldimethylammonium bromide) (C12C2C12) and dodecyltrimethylammonium bromide (DTAB) at the air/water interface, respectively. In the two systems,the surfactant concentrations are both 28 wt.%, and other conditions are also the same. After reaching the thermodynamic equilibrium, the concentration profiles, the radial distributions functions (RDF) and the mean squared displacement (MSD) are investigated. Theresults reveal that the surface activity of C12C2C12 suffactant is higher than DTAB surfactant.
Molecular dynamics (MD) simulation are used to study the properties of gemini surfactant of ethyl-α,ω-bis(dodecyldimethylammonium bromide) (C12C2C12) and dodecyltrimethylammonium bromide (DTAB) at the air/water interface, respectively. In the two systems,the surfactant concentrations are both 28 wt.%, and other conditions are also the same. After reaching the thermodynamic equilibrium, the concentration profiles, the radial distributions functions (RDF) and the mean squared displacement (MSD) are investigated. Theresults reveal that the surface activity of C12C2C12 suffactant is higher than DTAB surfactant.
2005, 16(5): 691-692
Abstract:
A new monolithic Ni/CeO2-ZrO2/γ-Al2O3 catalyst for combined partial oxidation and CO2 reforming of methane was prepared. The result shows that the addition of O2 to the feed can improve the activity of the catalyst and adjust the H2/CO ratio of the productive gases.
A new monolithic Ni/CeO2-ZrO2/γ-Al2O3 catalyst for combined partial oxidation and CO2 reforming of methane was prepared. The result shows that the addition of O2 to the feed can improve the activity of the catalyst and adjust the H2/CO ratio of the productive gases.
2005, 16(5): 693-696
Abstract:
Electronic spectra of substituted triphenylamines are investigated in this paper by time dependent perturbation theory and ZINDO/1-CI calculation.
Electronic spectra of substituted triphenylamines are investigated in this paper by time dependent perturbation theory and ZINDO/1-CI calculation.
2005, 16(5): 697-700
Abstract:
The adsorption of urea nitrogen onto chitosan coated dialdehyde cellulose (CDAC)under catalysis of immobilized urease in gelatin membrane (IE) was studied in batch system. The pseudo first-order and second-order kinetic models were used to describe the kinetic data, and the rate constants were evaluated. The experimental data fitted well to the second-order kinetic model.
The adsorption of urea nitrogen onto chitosan coated dialdehyde cellulose (CDAC)under catalysis of immobilized urease in gelatin membrane (IE) was studied in batch system. The pseudo first-order and second-order kinetic models were used to describe the kinetic data, and the rate constants were evaluated. The experimental data fitted well to the second-order kinetic model.
2005, 16(5): 701-704
Abstract:
Safranine, a cationic dye, was removed from synthetic wastewater by ion flotation.Over 98% of safranine was removed from the solution in 10 min. A stoichiometric amount of surfactant (1 mol of surfactant to 1 mol of dye) was found to be most effective for safranine removal. The separation efficiency of safranine decreased with increasing concentration of NaNO3. Safranine was also removed by adsorbing colloid flotation technique using Fe(OH)3 as the coagulant. Sodium lauryl sulfate was used as the collector, and over 97% of safranine was removed in 5 min. The separation efficiency decreased with increasing ionic strength of the solution. The deleterious effect of neutral salt was compensated somewhat with the aid of A13+ as the activator. Both ion flotation and adsorbing colloid flotation may be applicable in the removal of safranine from wastewater.
Safranine, a cationic dye, was removed from synthetic wastewater by ion flotation.Over 98% of safranine was removed from the solution in 10 min. A stoichiometric amount of surfactant (1 mol of surfactant to 1 mol of dye) was found to be most effective for safranine removal. The separation efficiency of safranine decreased with increasing concentration of NaNO3. Safranine was also removed by adsorbing colloid flotation technique using Fe(OH)3 as the coagulant. Sodium lauryl sulfate was used as the collector, and over 97% of safranine was removed in 5 min. The separation efficiency decreased with increasing ionic strength of the solution. The deleterious effect of neutral salt was compensated somewhat with the aid of A13+ as the activator. Both ion flotation and adsorbing colloid flotation may be applicable in the removal of safranine from wastewater.
2005, 16(5): 705-708
Abstract:
The present paper employed density function theory to investigate two reaction pathways for isomerization of enol ester proposed by Yang(path a) and the present authors(path a),respectively. The base catalytic effects of solvent triethylamine on these two reactions were also evaluated. It is demonstrated that path B is more preferable than path a due to low barrier height for the rate-determining step.
The present paper employed density function theory to investigate two reaction pathways for isomerization of enol ester proposed by Yang(path a) and the present authors(path a),respectively. The base catalytic effects of solvent triethylamine on these two reactions were also evaluated. It is demonstrated that path B is more preferable than path a due to low barrier height for the rate-determining step.
2005, 16(5): 709-710
Abstract:
Edge-adjacency index and information topological index for 82 molecules of alkanes have been constructed and calculated. The topological indices were used to correlate with seven physical properties of the alkanes. Some empirical equations were obtained through regression.The regression and calculation results show a good agreement of the topological indices and the properties.
Edge-adjacency index and information topological index for 82 molecules of alkanes have been constructed and calculated. The topological indices were used to correlate with seven physical properties of the alkanes. Some empirical equations were obtained through regression.The regression and calculation results show a good agreement of the topological indices and the properties.
