Login In
2005 Volume 16 Issue 7
2005, 16(7): 853-855
Abstract:
A ferrocenylsulfides 1-2 mediated sulfur ylide epoxidation reaction was found to stereoselectively afford trans-oxiranes in excellent yields with recoverable starting material.
A ferrocenylsulfides 1-2 mediated sulfur ylide epoxidation reaction was found to stereoselectively afford trans-oxiranes in excellent yields with recoverable starting material.
2005, 16(7): 856-858
Abstract:
O-Phosphoryl serine derivative can perform self-catalytic esterification reaction in the mixture of CH3OH and CHCl3 at the room temperature. The phosphoryl group participation was the key step of the esterification. This type of reactions were proposed through an intermediate of mixed phosphoric-carboxylic anhydride that might provide a clue to the function of the phosphoryl group in the phosphorylated enzymes and in the prebiotic synthesis of protein.
O-Phosphoryl serine derivative can perform self-catalytic esterification reaction in the mixture of CH3OH and CHCl3 at the room temperature. The phosphoryl group participation was the key step of the esterification. This type of reactions were proposed through an intermediate of mixed phosphoric-carboxylic anhydride that might provide a clue to the function of the phosphoryl group in the phosphorylated enzymes and in the prebiotic synthesis of protein.
2005, 16(7): 859-862
Abstract:
The novel bone-targeted agents were designed and synthesized by the combination of raloxifene and bisphosphonates. The anti-osteoporosis effect was evaluated by bone mineral density (BMD) obtained from OVX mice in vivo. The results indicated that the compound 8, 9 not only prevented ovariectomy induced loss of bone but also enhanced BMD to 0.87% and 19.67% compared to Sham, respectively.
The novel bone-targeted agents were designed and synthesized by the combination of raloxifene and bisphosphonates. The anti-osteoporosis effect was evaluated by bone mineral density (BMD) obtained from OVX mice in vivo. The results indicated that the compound 8, 9 not only prevented ovariectomy induced loss of bone but also enhanced BMD to 0.87% and 19.67% compared to Sham, respectively.
2005, 16(7): 863-866
Abstract:
The Schiff bases bearing ferrocenylphenyl and diferrocenylphenyl groups were synthesized by the reactions of m-ferrocenylaniline with salicylaldehyde or 1, 4-bis (2'-formylphenyl)-1, 4-dioxabutane. The title compounds were characterized by elemental analysis, IR, 1H NMR and X-ray structural determination.
The Schiff bases bearing ferrocenylphenyl and diferrocenylphenyl groups were synthesized by the reactions of m-ferrocenylaniline with salicylaldehyde or 1, 4-bis (2'-formylphenyl)-1, 4-dioxabutane. The title compounds were characterized by elemental analysis, IR, 1H NMR and X-ray structural determination.
2005, 16(7): 867-870
Abstract:
In order to search for new potent anti-cancer agents, a series of boswellic acid derivatives were designed and synthesized. Six of them were identified by IR, NMR and MS as new compounds and biologic assay of anti-cancer is underway.
In order to search for new potent anti-cancer agents, a series of boswellic acid derivatives were designed and synthesized. Six of them were identified by IR, NMR and MS as new compounds and biologic assay of anti-cancer is underway.
2005, 16(7): 871-874
Abstract:
Two modes of heterogeneous photoisomerization of trans-vitamin D3 to cis-vitamin D3are described. The occurrence of isomerization on the substrate bounded to the polymeric support gives us the possibility in succession synthesis of 1α-hydroxyvitamin D3. The polymer-bound anthracene can sensitize isomerization of trans-vitamin D3 to cis-vitamin D3 efficiently and ease the separation process.
Two modes of heterogeneous photoisomerization of trans-vitamin D3 to cis-vitamin D3are described. The occurrence of isomerization on the substrate bounded to the polymeric support gives us the possibility in succession synthesis of 1α-hydroxyvitamin D3. The polymer-bound anthracene can sensitize isomerization of trans-vitamin D3 to cis-vitamin D3 efficiently and ease the separation process.
2005, 16(7): 875-878
Abstract:
A series of novel oxazolidinone analogues were prepared by a new and efficient synthetic method and their antibacterial activities were determined. These compounds were characterized by LC-MS and 1H NMR.
A series of novel oxazolidinone analogues were prepared by a new and efficient synthetic method and their antibacterial activities were determined. These compounds were characterized by LC-MS and 1H NMR.
2005, 16(7): 879-882
Abstract:
The exploration of C2-symmetric chiral aminophenols and aminonaphthols is described.Seven new ligands have been successfully synthesized using Mannich reaction as a key step.Four of them have C2-symmetry and their structure has been fully characterized by means of NMR and X-ray crystallography.
The exploration of C2-symmetric chiral aminophenols and aminonaphthols is described.Seven new ligands have been successfully synthesized using Mannich reaction as a key step.Four of them have C2-symmetry and their structure has been fully characterized by means of NMR and X-ray crystallography.
2005, 16(7): 883-885
Abstract:
A new hetero-six-nuclear cluster was synthesized and determined by X-ray diffraction technique. The four-carboxylate groups are bound to the Cu(Ⅱ) atoms to form Cu(OR)4Cu paddle-wheel-type cage between two DMF as the basis for the cluster. The distance of two copper(Ⅱ) atoms is 2.642 Å, and they are bridged by the carboxylate groups. A huge system plane was auto-assembled by four host molecules and two Cu (Ⅱ) ions, which was observed in the crystal structure.
A new hetero-six-nuclear cluster was synthesized and determined by X-ray diffraction technique. The four-carboxylate groups are bound to the Cu(Ⅱ) atoms to form Cu(OR)4Cu paddle-wheel-type cage between two DMF as the basis for the cluster. The distance of two copper(Ⅱ) atoms is 2.642 Å, and they are bridged by the carboxylate groups. A huge system plane was auto-assembled by four host molecules and two Cu (Ⅱ) ions, which was observed in the crystal structure.
2005, 16(7): 886-888
Abstract:
A rapid and facile preparation of benzo-[b]-pyran derivatives through condensation of chalcone and 5, 5-dimethyl-1,3-cyclohexandione under microwave irradiation in the presence of catalytic amount of InCI3·4H2O has been developed.with its high effciency,operational simplicity and environmental benignancy, this method may provide a useful alternative for the preparation of benzo-[b]-pyran derivatives.
A rapid and facile preparation of benzo-[b]-pyran derivatives through condensation of chalcone and 5, 5-dimethyl-1,3-cyclohexandione under microwave irradiation in the presence of catalytic amount of InCI3·4H2O has been developed.with its high effciency,operational simplicity and environmental benignancy, this method may provide a useful alternative for the preparation of benzo-[b]-pyran derivatives.
2005, 16(7): 889-892
Abstract:
To search for a better prodrug of 4-aminosalicylic acid that is expected to deliver stably parent drug to colon against the inflammatory bowel disease, a novel 4-aminosalicylic acid derivative was designed and synthesized from 4-aminosalicylic acid. 4-Aminosalicylglycine was prepared from 4-aminosalicylic acid by protecting amino and hydroxyl groups with benzyloxycarbonyl and acetyl, respectively, then the carboxylic acid was converted to acyl chloride which was treated with glycine. After removing the protection groups, 4-aminosalicylglycine was obtained. All the compounds were characterized by FT-IR, 1H-NMR, 13C-NMR spectra. In vivo experiment on rats suggested that the curative effect of 4-aminosalicylglycine was more effective than that of 4-aminosalicylic acid.
To search for a better prodrug of 4-aminosalicylic acid that is expected to deliver stably parent drug to colon against the inflammatory bowel disease, a novel 4-aminosalicylic acid derivative was designed and synthesized from 4-aminosalicylic acid. 4-Aminosalicylglycine was prepared from 4-aminosalicylic acid by protecting amino and hydroxyl groups with benzyloxycarbonyl and acetyl, respectively, then the carboxylic acid was converted to acyl chloride which was treated with glycine. After removing the protection groups, 4-aminosalicylglycine was obtained. All the compounds were characterized by FT-IR, 1H-NMR, 13C-NMR spectra. In vivo experiment on rats suggested that the curative effect of 4-aminosalicylglycine was more effective than that of 4-aminosalicylic acid.
2005, 16(7): 893-896
Abstract:
Reduction of 1-deoxy-13-oxotaxanes has been studied under different reaction conditions.Some interesting reactions were reported.
Reduction of 1-deoxy-13-oxotaxanes has been studied under different reaction conditions.Some interesting reactions were reported.
2005, 16(7): 897-899
Abstract:
The reaction of aromatic aldehydes 1 with 5, 5-dimethyl-1, 3-cyclohexandione 2 was investigated in this paper by using[bmim] [BF4] as the reaction medium. It was found that when the reaction was carried out in the presence of catalytic amount of FeCl3·6H2O, xanthenediones 3 was obtained in high yields. On the other hand, when a combination of trimethylchlorosilane (TMSCl) and FeCl3·6H2O was employed as the catalyst, the reaction afforded ring-opening derivatives of xanthenediones 4 with high efficiency.
The reaction of aromatic aldehydes 1 with 5, 5-dimethyl-1, 3-cyclohexandione 2 was investigated in this paper by using[bmim] [BF4] as the reaction medium. It was found that when the reaction was carried out in the presence of catalytic amount of FeCl3·6H2O, xanthenediones 3 was obtained in high yields. On the other hand, when a combination of trimethylchlorosilane (TMSCl) and FeCl3·6H2O was employed as the catalyst, the reaction afforded ring-opening derivatives of xanthenediones 4 with high efficiency.
2005, 16(7): 900-902
Abstract:
Dipyrromethanes were obtained in moderate yields by the condensation of ketone and pyrrole in the presence of ionic liquid[Hmim]BF4 without using any strong acid and other organic solvent.
Dipyrromethanes were obtained in moderate yields by the condensation of ketone and pyrrole in the presence of ionic liquid[Hmim]BF4 without using any strong acid and other organic solvent.
2005, 16(7): 903-905
Abstract:
An efficient method is reported for the synthesis of phenacyl esters by reaction of carboxylic acids with α-bromoacetophenone promoted by potassium fluoride in ionic liquid[Bmim]PF6, the yield of the reaction is almost quantitative and the products are essentially pure.
An efficient method is reported for the synthesis of phenacyl esters by reaction of carboxylic acids with α-bromoacetophenone promoted by potassium fluoride in ionic liquid[Bmim]PF6, the yield of the reaction is almost quantitative and the products are essentially pure.
2005, 16(7): 906-908
Abstract:
A variety of carbonyl compounds can be converted into oximes efficiently and conveniently in a novel ionic liquid/water bi-phasic system in the presence of sodium bicarbonate at ambient temperature. The ionic liquid 1-butyl-3-methyl imidazolium hexafluorophosphate[bmim]PF6 is immiscible with water or diethyl ether and can be easily recycled for reuse without noticeable droping in activity after separation of the products. The protocol is rapid, the yields are excellent, the method is simple and the ionic liquid can be reused.
A variety of carbonyl compounds can be converted into oximes efficiently and conveniently in a novel ionic liquid/water bi-phasic system in the presence of sodium bicarbonate at ambient temperature. The ionic liquid 1-butyl-3-methyl imidazolium hexafluorophosphate[bmim]PF6 is immiscible with water or diethyl ether and can be easily recycled for reuse without noticeable droping in activity after separation of the products. The protocol is rapid, the yields are excellent, the method is simple and the ionic liquid can be reused.
2005, 16(7): 909-910
Abstract:
A mild Porco's two-step, one-pot condensation reaction for the preparation of 3-aryl-5-phenylselenomethyl 1, 2, 4-oxadiazole through phenylseleno acetic acid and benzamidoxime was reported. And further deselenenylation of 3-aryl-5-phenylselenomethyl 1, 2, 4-oxadiazole was studied.
A mild Porco's two-step, one-pot condensation reaction for the preparation of 3-aryl-5-phenylselenomethyl 1, 2, 4-oxadiazole through phenylseleno acetic acid and benzamidoxime was reported. And further deselenenylation of 3-aryl-5-phenylselenomethyl 1, 2, 4-oxadiazole was studied.
2005, 16(7): 911-914
Abstract:
Two new spirostanol saponins, (25S)-spirostane-1β,3β,5β-triol 3-O-β-D-glucopyranoside 1 and rhodeasapogenin 3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside 2, together with a known saponin, rhodeasapogenin 3-O-β-D-glucopyranoside 3, were isolated from the underground parts of Tupistra chinensis Bak.. Their structures were determined by spectroscopic analysis.
Two new spirostanol saponins, (25S)-spirostane-1β,3β,5β-triol 3-O-β-D-glucopyranoside 1 and rhodeasapogenin 3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside 2, together with a known saponin, rhodeasapogenin 3-O-β-D-glucopyranoside 3, were isolated from the underground parts of Tupistra chinensis Bak.. Their structures were determined by spectroscopic analysis.
2005, 16(7): 915-917
Abstract:
A new sesquiterpene with a unusual modified germacrane skeleton was isolated from the ethanol extracts of the roots of Biondia hemsleyana and its structure was elucidated as 3β-hydroxy4,14-cyclogermacra-11-en-9-one by the spectroscopic methods and X-ray crystallography.
A new sesquiterpene with a unusual modified germacrane skeleton was isolated from the ethanol extracts of the roots of Biondia hemsleyana and its structure was elucidated as 3β-hydroxy4,14-cyclogermacra-11-en-9-one by the spectroscopic methods and X-ray crystallography.
2005, 16(7): 918-920
Abstract:
A new coumestan, 3, 9-dihydroxy-4, 8-dimethoxycoumestan, was isolated from Arachis hypogaea L. together with two known compounds:3, 9-dihydroxy-4-methoxycoumestan and 3,9-dihydroxy-8-methoxycoumestan. The structure was established by spectroscopic methods.
A new coumestan, 3, 9-dihydroxy-4, 8-dimethoxycoumestan, was isolated from Arachis hypogaea L. together with two known compounds:3, 9-dihydroxy-4-methoxycoumestan and 3,9-dihydroxy-8-methoxycoumestan. The structure was established by spectroscopic methods.
2005, 16(7): 921-924
Abstract:
A new compound, named heteraltaic acid was isolated from the flowers of Heteropappus altaicus (willd) Novopokr.. The compound was elucidated as (5R, 6S, 8aS)-5-[2-(3-furyl) ethyl-5, 6, 8a-trimethyl-4a, 5, 6, 7, 8, 8a-hexahydro-1-naphthalenecarboxylic acid]by the combination of 1D and 2D NMR techniques (HSQC, HMBC) and X-ray analysis.
A new compound, named heteraltaic acid was isolated from the flowers of Heteropappus altaicus (willd) Novopokr.. The compound was elucidated as (5R, 6S, 8aS)-5-[2-(3-furyl) ethyl-5, 6, 8a-trimethyl-4a, 5, 6, 7, 8, 8a-hexahydro-1-naphthalenecarboxylic acid]by the combination of 1D and 2D NMR techniques (HSQC, HMBC) and X-ray analysis.
2005, 16(7): 925-927
Abstract:
A new labdane-type diterpene glycoside 1, chlorophytoside A, had been isolated from Chlorophytum laxum R.Br. The structure had been elucidated as (10S)-6α-hydroxylabda-8,13-dien-15,16-olide 3R-O-β-D-glucopyranoside on the basis of chemical and spectroscopic data.
A new labdane-type diterpene glycoside 1, chlorophytoside A, had been isolated from Chlorophytum laxum R.Br. The structure had been elucidated as (10S)-6α-hydroxylabda-8,13-dien-15,16-olide 3R-O-β-D-glucopyranoside on the basis of chemical and spectroscopic data.
2005, 16(7): 928-930
Abstract:
Two new glycosides named as ternatoside A 1 and ternatoside B 2 were isolated from the roots of Ranunculus ternatus, the structures were determined by 1D and 2D NMR, ESI-MS techniques, and chemical methods.
Two new glycosides named as ternatoside A 1 and ternatoside B 2 were isolated from the roots of Ranunculus ternatus, the structures were determined by 1D and 2D NMR, ESI-MS techniques, and chemical methods.
2005, 16(7): 931-934
Abstract:
The reaction between chloranilic acid and water in alcohol was studied spectrophotometrically. The conditions of reaction were investigated in detail. The stable purple complex with an absorption wavelength at 530 nm was produced from the reaction between chloranilic acid and water. As a method for determination of H2O, Beer's law was obeyed in range of 0-6.0% or 0-8.0% (V/V) with the detection limit of 0.13%. The relative standard deviation (RSD) was less than 2%. The proposed method has been applied to determination of trace amount of water in ethanol, flour and food flavoring, respectively. The recoveries of water in samples were 97~102%.
The reaction between chloranilic acid and water in alcohol was studied spectrophotometrically. The conditions of reaction were investigated in detail. The stable purple complex with an absorption wavelength at 530 nm was produced from the reaction between chloranilic acid and water. As a method for determination of H2O, Beer's law was obeyed in range of 0-6.0% or 0-8.0% (V/V) with the detection limit of 0.13%. The relative standard deviation (RSD) was less than 2%. The proposed method has been applied to determination of trace amount of water in ethanol, flour and food flavoring, respectively. The recoveries of water in samples were 97~102%.
2005, 16(7): 935-938
Abstract:
A simple recombinant PCR method was used to delete the dszB gene responsible for the slowest step of the Dsz pathway and allow the accumulation of hydroxyphenyl benzene sulfinate (HPBS) in the recombinant E. coli. Using GC/MS, HPBS accumulation was confirmed. The recombinant E. coli could also desulfurize Cx-DBT to corresponding Cx-HPBS. The result gave a new insight to BDS process and explored a new method to obtain valuable surfactants from cheap raw materials.
A simple recombinant PCR method was used to delete the dszB gene responsible for the slowest step of the Dsz pathway and allow the accumulation of hydroxyphenyl benzene sulfinate (HPBS) in the recombinant E. coli. Using GC/MS, HPBS accumulation was confirmed. The recombinant E. coli could also desulfurize Cx-DBT to corresponding Cx-HPBS. The result gave a new insight to BDS process and explored a new method to obtain valuable surfactants from cheap raw materials.
2005, 16(7): 939-942
Abstract:
The period-3 behaviors of 105 exons from 20 genes in human were studied by Fourier power spectrum. The results indicated that not all exons show the period-3 behavior. The exons were adjusted in order to make them accord with the order of the protein translated, and we found that the period-3 character is relation to the length of exons and the bases distribution in the three codon position. Furthermore, as long as the exons with period-3 behavior accord with the order of protein translated, they would exhibit the synonymous codons usage preference, and the codons with g/c at the third position are used in higher frequency. The results are significant to the gene prediction and the research on the introns.
The period-3 behaviors of 105 exons from 20 genes in human were studied by Fourier power spectrum. The results indicated that not all exons show the period-3 behavior. The exons were adjusted in order to make them accord with the order of the protein translated, and we found that the period-3 character is relation to the length of exons and the bases distribution in the three codon position. Furthermore, as long as the exons with period-3 behavior accord with the order of protein translated, they would exhibit the synonymous codons usage preference, and the codons with g/c at the third position are used in higher frequency. The results are significant to the gene prediction and the research on the introns.
2005, 16(7): 943-946
Abstract:
The binding between three surface-active substituted 3H-indole fluorescence probes and bovine serum albumin (BSA) in aqueous solution was studied using fluorescence quenching. The binding constants of 3H-indole molecules with BSA were obtained. According to the Forster resonance energy transfer theory, the distances between 3H-indole molecules and tryptophan of BSA were calculated. The results show that the oligoethyloxyethylene chain of 3H-indole molecules is longer, the binding between them is stronger, the energy transfer efficiency is higher,and the distance between tryptophan and 3H-indole is nearer.
The binding between three surface-active substituted 3H-indole fluorescence probes and bovine serum albumin (BSA) in aqueous solution was studied using fluorescence quenching. The binding constants of 3H-indole molecules with BSA were obtained. According to the Forster resonance energy transfer theory, the distances between 3H-indole molecules and tryptophan of BSA were calculated. The results show that the oligoethyloxyethylene chain of 3H-indole molecules is longer, the binding between them is stronger, the energy transfer efficiency is higher,and the distance between tryptophan and 3H-indole is nearer.
2005, 16(7): 947-950
Abstract:
The addition of propranolol induced the aggregation of gold nanoparticles, and increased Rayleigh light scattering (RLS) intensity greatly. The interaction between them was studied by RLS spectrum, UV-Vis spectrum and transmission electron microscopy (TEM). Based on these results, a novel method was proposed for propranolol assay. With the combination of solid phase microextraction (SPME), the proposed method was successfully applied to determine propranolol in urine.
The addition of propranolol induced the aggregation of gold nanoparticles, and increased Rayleigh light scattering (RLS) intensity greatly. The interaction between them was studied by RLS spectrum, UV-Vis spectrum and transmission electron microscopy (TEM). Based on these results, a novel method was proposed for propranolol assay. With the combination of solid phase microextraction (SPME), the proposed method was successfully applied to determine propranolol in urine.
2005, 16(7): 951-954
Abstract:
A novel ZnO/Chitosan composite matrix was developed to fabricate the H2O2 biosensor.This material combined the advantages of inorganic species, ZnO, and organic polymer, chitosan.Horseradish peroxidase immobilized in the material maintained its activity well as the usage of glutaraldehyde was avoided. The activity of enzyme was 7.9 times greater than the cross-linked enzyme. The parameters affecting the fabrication and experimental conditions of biosensors were optimized. With the aid of hydroquinone mediator, the biosensor had a fast response of less than 10s. The linear range was 5.0×10-6 to 2.0×10-3 mol/L with a sensitivity of 43.8 μAL/mmol.This matrix can also be used to immobilize other biomolecule.
A novel ZnO/Chitosan composite matrix was developed to fabricate the H2O2 biosensor.This material combined the advantages of inorganic species, ZnO, and organic polymer, chitosan.Horseradish peroxidase immobilized in the material maintained its activity well as the usage of glutaraldehyde was avoided. The activity of enzyme was 7.9 times greater than the cross-linked enzyme. The parameters affecting the fabrication and experimental conditions of biosensors were optimized. With the aid of hydroquinone mediator, the biosensor had a fast response of less than 10s. The linear range was 5.0×10-6 to 2.0×10-3 mol/L with a sensitivity of 43.8 μAL/mmol.This matrix can also be used to immobilize other biomolecule.
2005, 16(7): 955-958
Abstract:
This study concentrated on the production of molecularly imprinted polymers (MIPs) as highly selective sorbents for felodipine (FLD), a representive dihydropyridine calcium antagonists.Demonstrated chromatographically through a selection factor, these MIPs showed high selectivity for the template molecule among a group of structurally similar compounds. The recognition was found to correlate with structural similarity to the template compound.
This study concentrated on the production of molecularly imprinted polymers (MIPs) as highly selective sorbents for felodipine (FLD), a representive dihydropyridine calcium antagonists.Demonstrated chromatographically through a selection factor, these MIPs showed high selectivity for the template molecule among a group of structurally similar compounds. The recognition was found to correlate with structural similarity to the template compound.
2005, 16(7): 959-962
Abstract:
A new series of ionic liquids have been prepared containing benzimidazolium cation (abbreviated as Bim). These salts were characterized by DSC, NMR, elemental analysis and thermogravimetric analysis. They showed different properties compared to imidazolium cation due to the introduction of benzene ring. The alkylation of benzene/diphenyl ether with 1-dodecene was carried in C4eBimBr-AlCl3 ionic liquids showing high catalytic activity when the mole ratio of C4eBimB:AlCl3 was 1:2.
A new series of ionic liquids have been prepared containing benzimidazolium cation (abbreviated as Bim). These salts were characterized by DSC, NMR, elemental analysis and thermogravimetric analysis. They showed different properties compared to imidazolium cation due to the introduction of benzene ring. The alkylation of benzene/diphenyl ether with 1-dodecene was carried in C4eBimBr-AlCl3 ionic liquids showing high catalytic activity when the mole ratio of C4eBimB:AlCl3 was 1:2.
2005, 16(7): 963-966
Abstract:
The surfactant TX-100 can be dissolved in ionic liquid bmimPF6 and decrease the surface tension of 1-butyl-3-methylimidazolium hexafluorophosphate (bmimPF6) solutions. Here,we confirmed that in this new system, the pure solvents need rearrangement at the air-water interface at the initial stage. The dynamic surface tension (DST) study shows that at the initial adsorption stage, the adsorption model of surfactant accords with the diffusion-controlled adsorption mechanism, and the dilute ionic liquids solutions is further close to the diffusion-controlled adsorption.
The surfactant TX-100 can be dissolved in ionic liquid bmimPF6 and decrease the surface tension of 1-butyl-3-methylimidazolium hexafluorophosphate (bmimPF6) solutions. Here,we confirmed that in this new system, the pure solvents need rearrangement at the air-water interface at the initial stage. The dynamic surface tension (DST) study shows that at the initial adsorption stage, the adsorption model of surfactant accords with the diffusion-controlled adsorption mechanism, and the dilute ionic liquids solutions is further close to the diffusion-controlled adsorption.
2005, 16(7): 967-970
Abstract:
Nanocrystalline TiO2 thin films were successfully prepared by a new "water-cooked" method on both conductive glass substrates and flexible substrates at low temperature.Dye-sensitized solar cells based on these films have exhibited high overall light-to-electricity conversion efficiencies of 4.67% and 1.94% on conductive glass substrate and flexible substrate,respectively, under the illumination at 100 mW/cm2.
Nanocrystalline TiO2 thin films were successfully prepared by a new "water-cooked" method on both conductive glass substrates and flexible substrates at low temperature.Dye-sensitized solar cells based on these films have exhibited high overall light-to-electricity conversion efficiencies of 4.67% and 1.94% on conductive glass substrate and flexible substrate,respectively, under the illumination at 100 mW/cm2.
2005, 16(7): 971-974
Abstract:
Poly (trimethylene-co-ethylene terephthalate) with various compositions of diol has been synthesized. The crystallization of copolyesters with high comonomer content was observed by both wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC). It was found that the copolyesters become less crystallizable with the involvement of the comonomer,the crystals of crystallizable copolyesters come from PTT or PET homopolymers. The glass transition temperature (Tg) of the copolyester increases with increasing PET component in the copolyester, and the relationship between Tg and composition obey both Fox equation and additive law, the former is better in describing this relationship.
Poly (trimethylene-co-ethylene terephthalate) with various compositions of diol has been synthesized. The crystallization of copolyesters with high comonomer content was observed by both wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC). It was found that the copolyesters become less crystallizable with the involvement of the comonomer,the crystals of crystallizable copolyesters come from PTT or PET homopolymers. The glass transition temperature (Tg) of the copolyester increases with increasing PET component in the copolyester, and the relationship between Tg and composition obey both Fox equation and additive law, the former is better in describing this relationship.
2005, 16(7): 975-978
Abstract:
Chiral phase-transfer catalysts, derived from cinchona alkaloids and Frechet dendritic wedges up to generation two, have been synthesized. These chiral dendritic molecules have been used as PTCs in the epoxidation of α,β-enones, showing a moderate level of asymmetric induction.
Chiral phase-transfer catalysts, derived from cinchona alkaloids and Frechet dendritic wedges up to generation two, have been synthesized. These chiral dendritic molecules have been used as PTCs in the epoxidation of α,β-enones, showing a moderate level of asymmetric induction.
2005, 16(7): 979-982
Abstract:
A photosensitive metal hydride electrode was prepared by modification with perovskite-type SrTiO3 photocatalyst. The photorechargeable properties of the prepared electrodes were investigated by using electrochemical cyclic voltammetry and EIS measurements. The results showed that the modified electrode exhibited the obvious photorechargeable properties. The reduction current increased remarkably under the xeon light irradiation compared with the unmodified electrode. During the photocharging process, the potential of the modified electrode shifted quickly to negative direction and a potential plateau of about -0.90V (vs. Hg/HgO) occurred at the end of light irradiation. The corresponding discharge capacity of the electrode was about 5.4 mAh/g.
A photosensitive metal hydride electrode was prepared by modification with perovskite-type SrTiO3 photocatalyst. The photorechargeable properties of the prepared electrodes were investigated by using electrochemical cyclic voltammetry and EIS measurements. The results showed that the modified electrode exhibited the obvious photorechargeable properties. The reduction current increased remarkably under the xeon light irradiation compared with the unmodified electrode. During the photocharging process, the potential of the modified electrode shifted quickly to negative direction and a potential plateau of about -0.90V (vs. Hg/HgO) occurred at the end of light irradiation. The corresponding discharge capacity of the electrode was about 5.4 mAh/g.
2005, 16(7): 983-986
Abstract:
A novel reagentless biosensor constructed by the organic dye nile blue (NB) and horseradish peroxidase (HRP) has been fabricated via layer-by-layer (LBL) self-assembly technique. NB premixed with polyanion poly (sodium-p-styrenesulfonate) (PSS) acts as the mediator between the immobilized HRP and the electrode surface. The response of the biosensor to hydrogen peroxide has been investigated. The linear range of the biosensor to hydrogen peroxide was from 0.20 mmol/L to 7.03 mmol/L with a sensitivity of 8.45 μA/(mmol/L).
A novel reagentless biosensor constructed by the organic dye nile blue (NB) and horseradish peroxidase (HRP) has been fabricated via layer-by-layer (LBL) self-assembly technique. NB premixed with polyanion poly (sodium-p-styrenesulfonate) (PSS) acts as the mediator between the immobilized HRP and the electrode surface. The response of the biosensor to hydrogen peroxide has been investigated. The linear range of the biosensor to hydrogen peroxide was from 0.20 mmol/L to 7.03 mmol/L with a sensitivity of 8.45 μA/(mmol/L).
2005, 16(7): 987-990
Abstract:
The reflection-absorption infrared (RAIR) was employed to study the crystallization kinetic of poly (ethylene terephthalate) (PET) ultrathin films. During isothermal crystallization the thinner PET film shows a slower kinetic compared with the thicker film. Moreover, the final crystallinity of films with various thickness was found decrease with thickness. The result of fitting our data to Avrami equation showed that the Avrami exponents decrease with film thickness.
The reflection-absorption infrared (RAIR) was employed to study the crystallization kinetic of poly (ethylene terephthalate) (PET) ultrathin films. During isothermal crystallization the thinner PET film shows a slower kinetic compared with the thicker film. Moreover, the final crystallinity of films with various thickness was found decrease with thickness. The result of fitting our data to Avrami equation showed that the Avrami exponents decrease with film thickness.
2005, 16(7): 991-994
Abstract:
Chitosan membrane was modified by the selective oxidization of chitosan molecules on its surface with NO2 gas. FTIR spectra indicated there were plenty of-COOH and-COO- groups on the modified membrane surface. The SEM study showed the modified membrane surface was rough rather than smooth as chitosan membrane. All antithrombosis test, hemolysis test and blood cell morphology observation with SEM revealed that modified chitosan membranes have superior blood compatibility to chitosan.
Chitosan membrane was modified by the selective oxidization of chitosan molecules on its surface with NO2 gas. FTIR spectra indicated there were plenty of-COOH and-COO- groups on the modified membrane surface. The SEM study showed the modified membrane surface was rough rather than smooth as chitosan membrane. All antithrombosis test, hemolysis test and blood cell morphology observation with SEM revealed that modified chitosan membranes have superior blood compatibility to chitosan.
