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2002 Volume 13 Issue 1
2002, 13(1): 1-2
Abstract:
The two-step Sonogashira coupling reaction took place rapidly under microwave activation conditions.PEG bound substrates acted as PTC and polymer support as well.Its yields are 80~90% and the products are in high purity.
The two-step Sonogashira coupling reaction took place rapidly under microwave activation conditions.PEG bound substrates acted as PTC and polymer support as well.Its yields are 80~90% and the products are in high purity.
2002, 13(1): 3-6
Abstract:
A microwave-assisted preparation of a series of Schiff-base via efficient condensation of salicylaldehyde and aryl amines without solvent is described in high yield as well as environmental friendship reaction in organic synthesis.
A microwave-assisted preparation of a series of Schiff-base via efficient condensation of salicylaldehyde and aryl amines without solvent is described in high yield as well as environmental friendship reaction in organic synthesis.
2002, 13(1): 7-8
Abstract:
A silica-supported zirconium based solid acid (ZS) has been used as catalyst for the Fries rearrangement of phenyl acetate (PA).The catalyst showed a higher PA conversion activity and a much higher selectivity for o-hydroxyacetophenone (o-HAP) than for strongly acidic zeolite catalysts.The supported catalyst was characterized by XRD, IR, XPS, pyridine-TPD and the surface area measurements.The catalytic properties were influenced significantly by pretreatment temperature.
A silica-supported zirconium based solid acid (ZS) has been used as catalyst for the Fries rearrangement of phenyl acetate (PA).The catalyst showed a higher PA conversion activity and a much higher selectivity for o-hydroxyacetophenone (o-HAP) than for strongly acidic zeolite catalysts.The supported catalyst was characterized by XRD, IR, XPS, pyridine-TPD and the surface area measurements.The catalytic properties were influenced significantly by pretreatment temperature.
2002, 13(1): 9-12
Abstract:
The Se-Se bond in diaryl diselenides was reduced by Zn/ZrCl4 system to produce selenide anions, which react with acyl chlorides or acid anhydrides to afford selenoesters in THF under mild and neutral conditions.
The Se-Se bond in diaryl diselenides was reduced by Zn/ZrCl4 system to produce selenide anions, which react with acyl chlorides or acid anhydrides to afford selenoesters in THF under mild and neutral conditions.
2002, 13(1): 13-16
Abstract:
Eight of new 5-oxo-[1]benzopyrano[2,3-b]pyridines as the analogues of tetracycline,were designed and synthesized, and their affinity to the hydroxyapatite-the inorganic composition of bone were tested.
Eight of new 5-oxo-[1]benzopyrano[2,3-b]pyridines as the analogues of tetracycline,were designed and synthesized, and their affinity to the hydroxyapatite-the inorganic composition of bone were tested.
2002, 13(1): 17-18
Abstract:
A new conformationally restricted cyclic analogue of muramyl dipeptide was designed and manually synthesized by our "Meshed-Bag Gathered-Bunch" method with a combination of Fmoc, allyl and N-1-(4,4-dimethyl–2,6-dioxocyclo-hexylidene)ethyl chemical protection strategy.
A new conformationally restricted cyclic analogue of muramyl dipeptide was designed and manually synthesized by our "Meshed-Bag Gathered-Bunch" method with a combination of Fmoc, allyl and N-1-(4,4-dimethyl–2,6-dioxocyclo-hexylidene)ethyl chemical protection strategy.
2002, 13(1): 19-22
Abstract:
The structures of five metabolites (2-6) of agarofuran 1 were confirmed by synthesis.The configuration of the secondary hydroxyl in 7 was determined by Horeau's method.The configuration of C-2 in compound 4 and 5 was determined by their stereochemistry and NMR.
The structures of five metabolites (2-6) of agarofuran 1 were confirmed by synthesis.The configuration of the secondary hydroxyl in 7 was determined by Horeau's method.The configuration of C-2 in compound 4 and 5 was determined by their stereochemistry and NMR.
2002, 13(1): 23-26
Abstract:
Six alkylene-linked dimers of (-)-huperzineA (6) were prepared.All these dimers are less potent than (-)-Hup A in inhibition of AChE.
Six alkylene-linked dimers of (-)-huperzineA (6) were prepared.All these dimers are less potent than (-)-Hup A in inhibition of AChE.
2002, 13(1): 27-28
Abstract:
A novel dihydroxyl azacrown ether chitosan was synthesized by reacting dihydroxyl azacrown ether with epoxy activated chitosan.The adsorption property of the azacrown ether chitosan for Pb2+, Cr3+, and Ag+, were determined.The experimental results showed that the dihydroxyl azacrown ether grafted chitosan has high adsorption capacity and high selectivity for some metal ions.
A novel dihydroxyl azacrown ether chitosan was synthesized by reacting dihydroxyl azacrown ether with epoxy activated chitosan.The adsorption property of the azacrown ether chitosan for Pb2+, Cr3+, and Ag+, were determined.The experimental results showed that the dihydroxyl azacrown ether grafted chitosan has high adsorption capacity and high selectivity for some metal ions.
2002, 13(1): 28-32
Abstract:
A series of novel polyphosphonates containing 5-flouro-N1-furanyl-N3-glyceroalkyl-uracil and formyl groups was synthesized by the condensation of 3-(ω-(1'-furanyl-5-flourouracil-3-yl) alkoxy)-1, 2-dihydroxy propane with phosphonyl dichloride.The products were characterized by IR, 1H NMR, 31P NMR, M,and elementalanalysis.The resultsof bioassay show that compound 8a possesses potential anticancer activity.
A series of novel polyphosphonates containing 5-flouro-N1-furanyl-N3-glyceroalkyl-uracil and formyl groups was synthesized by the condensation of 3-(ω-(1'-furanyl-5-flourouracil-3-yl) alkoxy)-1, 2-dihydroxy propane with phosphonyl dichloride.The products were characterized by IR, 1H NMR, 31P NMR, M,and elementalanalysis.The resultsof bioassay show that compound 8a possesses potential anticancer activity.
2002, 13(1): 33-36
Abstract:
Poly (L-lactide)-poly(ethylene glycol) multiblock copolymers with predetermined block lengths were synthesized by polycondensation of PLA diols and PEG diacids.These copolymers presented special properties, such as better miscibility between the two components, low crystallinity and better hydrophilicity, which can be modulated by adjusting the block lengths of the two components.
Poly (L-lactide)-poly(ethylene glycol) multiblock copolymers with predetermined block lengths were synthesized by polycondensation of PLA diols and PEG diacids.These copolymers presented special properties, such as better miscibility between the two components, low crystallinity and better hydrophilicity, which can be modulated by adjusting the block lengths of the two components.
2002, 13(1): 37-40
Abstract:
The synthesis and crystal structure of a novel calix[8]arene ester are reported herein.The calix[8]arene ester derivative has been characterized by IR, NMR and X-ray crystal analysis.The X-ray structure analysis revealed that the 8 phenolic hydroxy groups of the calix[8]arene have been substituted by 4 diethyl dibromomalonate molecules with each two adjacent hydroxy oxygen atoms attached to a bridge diethyl malonate.
The synthesis and crystal structure of a novel calix[8]arene ester are reported herein.The calix[8]arene ester derivative has been characterized by IR, NMR and X-ray crystal analysis.The X-ray structure analysis revealed that the 8 phenolic hydroxy groups of the calix[8]arene have been substituted by 4 diethyl dibromomalonate molecules with each two adjacent hydroxy oxygen atoms attached to a bridge diethyl malonate.
2002, 13(1): 41-44
Abstract:
B3LYP/6-31+g (d, p) method was used to calculate the lithium and sodium affinities of n-alkyl fluoride.These affinities were found to obey the Holmes relationship, i.e. they correlate linearly with the quotient n/(n+1), where n is the number of carbon atoms in the alkyl chain.From the correlation the limiting values of lithium and sodium affinities for very long alkyl chain were predicted to be-153.3 kJ/mol and-108.4 kJ/mol, respectively.
B3LYP/6-31+g (d, p) method was used to calculate the lithium and sodium affinities of n-alkyl fluoride.These affinities were found to obey the Holmes relationship, i.e. they correlate linearly with the quotient n/(n+1), where n is the number of carbon atoms in the alkyl chain.From the correlation the limiting values of lithium and sodium affinities for very long alkyl chain were predicted to be-153.3 kJ/mol and-108.4 kJ/mol, respectively.
2002, 13(1): 45-48
Abstract:
The structures of several recently reported organometallic NLO chromophores, (thiophene) manganese tricarbonyl cations, were fully optimized at the DFT non-local (GGA) level.The calculated results show that the fragments 2-SC4H3CH=CHC6H4-R in these organometallic chromophores are not planar with dihedral angles of 42.2~59.8° between two aromatic rings,which are different from those of uncoordinated counterparts.Based on the DFT geometry optimization,the second-order nonlinear optical polarizabilities were calculated by using RPA method.The calculated results indicate that incorporation of~Mn(CO)3+ unit with thiophene leads to asubstantial increase in the second-order polarizability (β).
The structures of several recently reported organometallic NLO chromophores, (thiophene) manganese tricarbonyl cations, were fully optimized at the DFT non-local (GGA) level.The calculated results show that the fragments 2-SC4H3CH=CHC6H4-R in these organometallic chromophores are not planar with dihedral angles of 42.2~59.8° between two aromatic rings,which are different from those of uncoordinated counterparts.Based on the DFT geometry optimization,the second-order nonlinear optical polarizabilities were calculated by using RPA method.The calculated results indicate that incorporation of~Mn(CO)3+ unit with thiophene leads to asubstantial increase in the second-order polarizability (β).
2002, 13(1): 49-52
Abstract:
Interlayer energy transfer between 2, 3-naphtho-10-hexadecylaza-15-crown-5 (NC16)and N-[1-(9-methoxyanthryl)]decylaza-15-crown-5 (A10C) within multilayer Langmuir-Blodgett films has been studied by steady-state fluorescence spectra.The donor and acceptor could be separated precisely by inserting stearic acid (SA) spacers.The efficiency of the energy transfer increases with the decrease in the donor-acceptor distance by a quadratic manner, suggesting the donor excitations are delocalized in the layer.
Interlayer energy transfer between 2, 3-naphtho-10-hexadecylaza-15-crown-5 (NC16)and N-[1-(9-methoxyanthryl)]decylaza-15-crown-5 (A10C) within multilayer Langmuir-Blodgett films has been studied by steady-state fluorescence spectra.The donor and acceptor could be separated precisely by inserting stearic acid (SA) spacers.The efficiency of the energy transfer increases with the decrease in the donor-acceptor distance by a quadratic manner, suggesting the donor excitations are delocalized in the layer.
2002, 13(1): 53-54
Abstract:
As indicated by kinetic ESR measurements, the key factor to affect electron recombination in the process of PET between C60 and amines is the space between donor and C60.To increase solubility of C60 in water, it was incorporated into micelle of surfactants.
As indicated by kinetic ESR measurements, the key factor to affect electron recombination in the process of PET between C60 and amines is the space between donor and C60.To increase solubility of C60 in water, it was incorporated into micelle of surfactants.
2002, 13(1): 55-58
Abstract:
In this paper, a novel method for fixed-node quantum Monte Carlo is given.We have derived an expansion of the eigenvalue of the energy for a system and proved that the value of the energy calculated using the traditional fixed-node quantum Monte Carlo method is only the zero order approximation of the eigenvalue of the energy.But when using our novel method, in the case of only increasing less computing amounts (<1%), we can obtain conveniently the first order approximation, second order approximation, and so on.We have calculated the values of the zero,first and second approximation (ε0,ε1 and ε2) of the energies of 11A1 state of CH2, 1Ag (C4h, acet)state of C8 and the ground-state of H2O using this novel method.The results indicate that for 11A1 state of CH2, 1Ag (C4h, acet) state of C8 and the ground-state of H2O it needs only the second order approximation to obtain electronic correlation energy with over 97%.This demonstrates that this novel method is very excellent in both the computing accuracy and the amount of calculation required.
In this paper, a novel method for fixed-node quantum Monte Carlo is given.We have derived an expansion of the eigenvalue of the energy for a system and proved that the value of the energy calculated using the traditional fixed-node quantum Monte Carlo method is only the zero order approximation of the eigenvalue of the energy.But when using our novel method, in the case of only increasing less computing amounts (<1%), we can obtain conveniently the first order approximation, second order approximation, and so on.We have calculated the values of the zero,first and second approximation (ε0,ε1 and ε2) of the energies of 11A1 state of CH2, 1Ag (C4h, acet)state of C8 and the ground-state of H2O using this novel method.The results indicate that for 11A1 state of CH2, 1Ag (C4h, acet) state of C8 and the ground-state of H2O it needs only the second order approximation to obtain electronic correlation energy with over 97%.This demonstrates that this novel method is very excellent in both the computing accuracy and the amount of calculation required.
2002, 13(1): 59-60
Abstract:
A new flavonol oligosaccharide, quercetin-3-O-[β-D-xylopyranosyl-(1→2)-α-L-rhamnopyranosyl-(1→6)]-β-D-glucopyranoside-3'-O-β-D-glucopyranoside, named aescuflavoside was isolated from Aesculus chinensis.It's structure was elucidated by spectra FAB-MS, 1D NMR and 2D NMR including1H NMR, 13C NMR, HMQC and HMBC techniques.
A new flavonol oligosaccharide, quercetin-3-O-[β-D-xylopyranosyl-(1→2)-α-L-rhamnopyranosyl-(1→6)]-β-D-glucopyranoside-3'-O-β-D-glucopyranoside, named aescuflavoside was isolated from Aesculus chinensis.It's structure was elucidated by spectra FAB-MS, 1D NMR and 2D NMR including1H NMR, 13C NMR, HMQC and HMBC techniques.
2002, 13(1): 61-64
Abstract:
Two alkaloids tylophoridicine D (1) and tylophoridicine E (2) have been isolated from Tylophora atrofolliculata.The structures of the compounds were elucidated on the basis of spect-roscopic analysis.
Two alkaloids tylophoridicine D (1) and tylophoridicine E (2) have been isolated from Tylophora atrofolliculata.The structures of the compounds were elucidated on the basis of spect-roscopic analysis.
2002, 13(1): 65-66
Abstract:
A new lupane-type triterpene was isolated from the resin of Boswellia carterii Birdw.Based on the spectral methods, its structure was elucidated as lup-20(29)-ene-3α-acetoxy-24-oic acid.
A new lupane-type triterpene was isolated from the resin of Boswellia carterii Birdw.Based on the spectral methods, its structure was elucidated as lup-20(29)-ene-3α-acetoxy-24-oic acid.
2002, 13(1): 67-68
Abstract:
From fermentation broth of soil fungus 254-2 obtained from Yunnan province, a new macrocylic trichochecene was isolated.The structure was determined on the basis of spectroscopic evidences especially the 2-D NMR spectra.
From fermentation broth of soil fungus 254-2 obtained from Yunnan province, a new macrocylic trichochecene was isolated.The structure was determined on the basis of spectroscopic evidences especially the 2-D NMR spectra.
2002, 13(1): 69-70
Abstract:
A new voltammetric enzyme immunoassay system was investigated based on p-nitrophenyl phosphate (PNPP) as the substrate for alkaline phosphatase (ALP).PNPP is enzymatically hydrolyzed and the product p-nitrophenol (PNP) is detected by differential pulse voltammetry (DPV), which can be oxidized at+1.02 V (vs.Ag/AgCl) on bare glass carbon electrode (GCE).The conditions for enzymatic reaction and electrochemical detection were studied.According to this method, ALP can be detected with a detection limit of 2.8×102 mU/L and a linear range of 4.0×102~1.0×106 mU/L.
A new voltammetric enzyme immunoassay system was investigated based on p-nitrophenyl phosphate (PNPP) as the substrate for alkaline phosphatase (ALP).PNPP is enzymatically hydrolyzed and the product p-nitrophenol (PNP) is detected by differential pulse voltammetry (DPV), which can be oxidized at+1.02 V (vs.Ag/AgCl) on bare glass carbon electrode (GCE).The conditions for enzymatic reaction and electrochemical detection were studied.According to this method, ALP can be detected with a detection limit of 2.8×102 mU/L and a linear range of 4.0×102~1.0×106 mU/L.
2002, 13(1): 71-72
Abstract:
Arsenazo M could bind with bovine serum albumin to form a complex in Clark-Lube buffer at pH 2.3 and room temperature, which gives a maximum absorption peak at 625 nm with a red shift of 75 nm compared with that of Arsenazo M itself.The apparent molar absorptivity of the BSA-Arsenazo M complex is 3.21×105 L·mol-1×cm-1.The linear ranges for protein determination are wide (at least 0-100 mg/mL).
Arsenazo M could bind with bovine serum albumin to form a complex in Clark-Lube buffer at pH 2.3 and room temperature, which gives a maximum absorption peak at 625 nm with a red shift of 75 nm compared with that of Arsenazo M itself.The apparent molar absorptivity of the BSA-Arsenazo M complex is 3.21×105 L·mol-1×cm-1.The linear ranges for protein determination are wide (at least 0-100 mg/mL).
2002, 13(1): 73-74
Abstract:
A new method called spline convolution (SC) for resolving overlapped peaks was proposed in this paper.The differential pulse voltammetric overlapped peaks of mixtures of Pb(II) and Tl(I) were investigated by this method, and satisfactory results were obtained.The results show excellent correlation between peak areas of the processed signals and the concentrations.
A new method called spline convolution (SC) for resolving overlapped peaks was proposed in this paper.The differential pulse voltammetric overlapped peaks of mixtures of Pb(II) and Tl(I) were investigated by this method, and satisfactory results were obtained.The results show excellent correlation between peak areas of the processed signals and the concentrations.
2002, 13(1): 75-78
Abstract:
Changes of composition and structure of various samples of polymethylsilsesquioxane (PMSQ) pyrolysed at different temperature under flowing nitrogen were investigated by means of FT-IR and X-ray photoelectron spectroscopy.Two temperature domains correspond to important changes in the chemical composition of PMSQ.The former (Tp < 500℃) is related to the transition from regular structure to irregular structure and the latter (Tp > 500℃) is associated with the organic-inorgnic transition.
Changes of composition and structure of various samples of polymethylsilsesquioxane (PMSQ) pyrolysed at different temperature under flowing nitrogen were investigated by means of FT-IR and X-ray photoelectron spectroscopy.Two temperature domains correspond to important changes in the chemical composition of PMSQ.The former (Tp < 500℃) is related to the transition from regular structure to irregular structure and the latter (Tp > 500℃) is associated with the organic-inorgnic transition.
2002, 13(1): 79-82
Abstract:
The properties of the carbon nanotube powder microelectrodes (denoted CNTPME) are remarkably altered by anodic pretreatment and preadsorption of mediators.It seems that anodic pretreatment leads the long and tangled carbon nanotubes to be partially cut shorter, resulting in more openings as shown by TEM.Besides, the anodic pretreatment may adjust the hydrophobicity of nanotubes to match with that of Os(bpy)32+.As a result, the real surface area and the ability of adsorbing mediator Os(bpy)32+ of the nanotubes are markedly increased so as to effectively catalyze NO2- reduction in acidic solution.
The properties of the carbon nanotube powder microelectrodes (denoted CNTPME) are remarkably altered by anodic pretreatment and preadsorption of mediators.It seems that anodic pretreatment leads the long and tangled carbon nanotubes to be partially cut shorter, resulting in more openings as shown by TEM.Besides, the anodic pretreatment may adjust the hydrophobicity of nanotubes to match with that of Os(bpy)32+.As a result, the real surface area and the ability of adsorbing mediator Os(bpy)32+ of the nanotubes are markedly increased so as to effectively catalyze NO2- reduction in acidic solution.
2002, 13(1): 83-86
Abstract:
The use of supercritical-fluid chromatography for determining partial molar volumes of ethyl esters of cis-5,8,11,14,17-eicosapentaenoic acid (EPA) and cis-4,7,10,13,16,19-docosa-hexaenoic acid (DHA) in supercritical carbon dioxide is presented and discussed.Partial molar volumes of EPA and DHA esters are obtained from the variation of the retention properties with the density of mobile phase at 313.15 K, 323.15 K, 333.15 K and in the pressure range from 9 MPa to 21 MPa.
The use of supercritical-fluid chromatography for determining partial molar volumes of ethyl esters of cis-5,8,11,14,17-eicosapentaenoic acid (EPA) and cis-4,7,10,13,16,19-docosa-hexaenoic acid (DHA) in supercritical carbon dioxide is presented and discussed.Partial molar volumes of EPA and DHA esters are obtained from the variation of the retention properties with the density of mobile phase at 313.15 K, 323.15 K, 333.15 K and in the pressure range from 9 MPa to 21 MPa.
2002, 13(1): 87-90
Abstract:
It was found that Dynol-604, a non-fluorous and no silicon-containing nonionic surfactant, was soluble in supercritical (SC) CO2.The phase behavior of SC CO2/Dynol-604/water system was studied.The results showed that one-phase water-in-CO2 microemulsions could be formed.The solubilization of methyl orange in the microemulsions proved further the existence of water domain in the microemulsions.
It was found that Dynol-604, a non-fluorous and no silicon-containing nonionic surfactant, was soluble in supercritical (SC) CO2.The phase behavior of SC CO2/Dynol-604/water system was studied.The results showed that one-phase water-in-CO2 microemulsions could be formed.The solubilization of methyl orange in the microemulsions proved further the existence of water domain in the microemulsions.
2002, 13(1): 91-94
Abstract:
Zeolite FAU was heated directly by microwave irradiation at 2450 MHz in an open system without special loading materials.It was discovered that zeolite X was heated to 1473 K about 90 seconds at power output of 400 W.HY type zeolite was also heated to 1373 K although it needed relative long time (about 11 minutes).Influences of exchangeable cations and adsorbed substances on zeolite1s ability to absorb microwaves were also discussed.
Zeolite FAU was heated directly by microwave irradiation at 2450 MHz in an open system without special loading materials.It was discovered that zeolite X was heated to 1473 K about 90 seconds at power output of 400 W.HY type zeolite was also heated to 1373 K although it needed relative long time (about 11 minutes).Influences of exchangeable cations and adsorbed substances on zeolite1s ability to absorb microwaves were also discussed.
