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2004 Volume 15 Issue 2
2004, 15(2): 127-130
Abstract:
The reactions of arylamine with ethyl acetoacetate catalyzed by a solid support are accelerated by microwave irradiation to result in a rapid and clean production of ethyl β-arylaminocrotonates.
The reactions of arylamine with ethyl acetoacetate catalyzed by a solid support are accelerated by microwave irradiation to result in a rapid and clean production of ethyl β-arylaminocrotonates.
2004, 15(2): 131-134
Abstract:
Five fluorinated podophyllotoxin derivatives were synthesized using dimethylamino-sulfurtrifluoride (DAST).
Five fluorinated podophyllotoxin derivatives were synthesized using dimethylamino-sulfurtrifluoride (DAST).
2004, 15(2): 135-137
Abstract:
β-2', 3'-Dideoxy-2'-fluoro-3'-hydroxymethylarabinofuranosylthymine 10 and cytosine 12 were synthesized from L-xylose and were found to be inactive against HIV-1 in acutely infected lymphocytes.
β-2', 3'-Dideoxy-2'-fluoro-3'-hydroxymethylarabinofuranosylthymine 10 and cytosine 12 were synthesized from L-xylose and were found to be inactive against HIV-1 in acutely infected lymphocytes.
2004, 15(2): 138-140
Abstract:
A convergent asymmetric synthesis of (2S, 3R, 4S, 12'R)-3-hydroxy-2-hydroxymethyl-4-(12'-methyloctadecyl)-N-(p-tolylsulfonyl)-azetidine, a key precursor of penazetidine A, has been achieved by starting from divinylcarbinol.
A convergent asymmetric synthesis of (2S, 3R, 4S, 12'R)-3-hydroxy-2-hydroxymethyl-4-(12'-methyloctadecyl)-N-(p-tolylsulfonyl)-azetidine, a key precursor of penazetidine A, has been achieved by starting from divinylcarbinol.
2004, 15(2): 141-142
Abstract:
An efficient total synthesis of (±)-3-(5-hydroxy-4, 7, 8-trimethyl-3E, 8-nonadiene)-Δ2-butenolide 1, an unusual homosesquiterpene, starting from geraniol 2 through ten steps are described.
An efficient total synthesis of (±)-3-(5-hydroxy-4, 7, 8-trimethyl-3E, 8-nonadiene)-Δ2-butenolide 1, an unusual homosesquiterpene, starting from geraniol 2 through ten steps are described.
2004, 15(2): 143-144
Abstract:
2, 5-Disubstituted oxazoles were prepared conveniently by treatment of aromatic α-methyl ketones and nitriles with poly[styrene(iodosodiacetate)] in one-pot process.
2, 5-Disubstituted oxazoles were prepared conveniently by treatment of aromatic α-methyl ketones and nitriles with poly[styrene(iodosodiacetate)] in one-pot process.
2004, 15(2): 145-147
Abstract:
The title compound 5 was synthesized in 45% yield by the reaction of compound 3 with α, α'-bis (bromomethyl)-2, 2'-bipyridine in CH3CN at 70℃ for 24 h.
The title compound 5 was synthesized in 45% yield by the reaction of compound 3 with α, α'-bis (bromomethyl)-2, 2'-bipyridine in CH3CN at 70℃ for 24 h.
2004, 15(2): 148-150
Abstract:
Promoted by active indium produced in situ by Sm/InCl3·4H2O system, arylidenecyano-acetates undergo reductive cyclodimerization to afford cyclopentamine derivatives with high stereoselectivity under mild conditions in aqueous media.
Promoted by active indium produced in situ by Sm/InCl3·4H2O system, arylidenecyano-acetates undergo reductive cyclodimerization to afford cyclopentamine derivatives with high stereoselectivity under mild conditions in aqueous media.
2004, 15(2): 151-154
Abstract:
New functional dendrimers bearing 4, 8 and 16 axial chiral units on their surface were synthesized from achiral PAMAM dendrimers and axial chiral (R)-BINOL derivative.
New functional dendrimers bearing 4, 8 and 16 axial chiral units on their surface were synthesized from achiral PAMAM dendrimers and axial chiral (R)-BINOL derivative.
2004, 15(2): 155-158
Abstract:
The synthesis and mesomorphic properties of two series of novel γ-substituted β-diketonates have been reported. All of the compounds 2, 4-dioxo-3-pentyl 4-[[4-(n-alkoxyl) cinnamoyl]oxy]cinnamatetes Ia-If (n=7-12) exhibit two monotropic phases(N and Sc) and have a wider mesophase range than the compounds 2, 4-dioxo-3-pentyl 4-[[4-(n-alkoxyl) benzoyl]oxy] cinnamatetes IIa-IIf (n=7-12), which display one monotropic nematic phase (n=7-10) or an enantiotropic nematic phase for n=11 or two enantiotropic phases (N and Sc) for n=12.
The synthesis and mesomorphic properties of two series of novel γ-substituted β-diketonates have been reported. All of the compounds 2, 4-dioxo-3-pentyl 4-[[4-(n-alkoxyl) cinnamoyl]oxy]cinnamatetes Ia-If (n=7-12) exhibit two monotropic phases(N and Sc) and have a wider mesophase range than the compounds 2, 4-dioxo-3-pentyl 4-[[4-(n-alkoxyl) benzoyl]oxy] cinnamatetes IIa-IIf (n=7-12), which display one monotropic nematic phase (n=7-10) or an enantiotropic nematic phase for n=11 or two enantiotropic phases (N and Sc) for n=12.
2004, 15(2): 159-162
Abstract:
1, 1-Diphenyl-2, 2-dicyanoethylene reacts with 10-methyl-9, 10-dihydroacridine in deaerated acetonitrile under irradiation with λ>320 nm to give the coupling product 1, 1-diphenyl-1-(10'-methyl-9'-acridinyl)-2, 2-dicyanoethane, which has been characterized by X-ray crystallographic, MS and NMR analyses.
1, 1-Diphenyl-2, 2-dicyanoethylene reacts with 10-methyl-9, 10-dihydroacridine in deaerated acetonitrile under irradiation with λ>320 nm to give the coupling product 1, 1-diphenyl-1-(10'-methyl-9'-acridinyl)-2, 2-dicyanoethane, which has been characterized by X-ray crystallographic, MS and NMR analyses.
2004, 15(2): 163-166
Abstract:
Novel C-nucleosides of tiazofurin analogue (2-[2-(hydroxymethyl)-1, 3-dioxolan-5-yl]1, 3-thiazole-4-carboxamide) and its thiol-substituted derivative (2-[2-(mercaptomethyl)-1, 3-dioxolan-5-yl]1, 3-thiazole-4-carboxamide) were synthesized from methyl acrylate through a multistep procedure. Their structures were confirmed by IR, 1HNMR, 13CNMR and elemental analysis.
Novel C-nucleosides of tiazofurin analogue (2-[2-(hydroxymethyl)-1, 3-dioxolan-5-yl]1, 3-thiazole-4-carboxamide) and its thiol-substituted derivative (2-[2-(mercaptomethyl)-1, 3-dioxolan-5-yl]1, 3-thiazole-4-carboxamide) were synthesized from methyl acrylate through a multistep procedure. Their structures were confirmed by IR, 1HNMR, 13CNMR and elemental analysis.
2004, 15(2): 167-168
Abstract:
Two new chiral pyridine prolinol derivatives have been synthesized from N-alkylation of (S)-α, α-diphenyl-2-pyrrolidinemethanol with 2-bromomethylpyridine and 2, 6-dibromo-methyl-pyridine. The catalytic asymmetric borane reduction of prochiral ketones and the asymmetric addition of diethylzinc to benzaldehyde were investigated.
Two new chiral pyridine prolinol derivatives have been synthesized from N-alkylation of (S)-α, α-diphenyl-2-pyrrolidinemethanol with 2-bromomethylpyridine and 2, 6-dibromo-methyl-pyridine. The catalytic asymmetric borane reduction of prochiral ketones and the asymmetric addition of diethylzinc to benzaldehyde were investigated.
2004, 15(2): 169-170
Abstract:
12-Oxo-1, 15-pentadecanlactam 7 was synthesized from cyclododecanone with a total yield of 36% in a seven-step reaction. The azide 5 to 12-nitro-1, 15-pentadecanlactam 6 is the key step featured by direct ring expansion.
12-Oxo-1, 15-pentadecanlactam 7 was synthesized from cyclododecanone with a total yield of 36% in a seven-step reaction. The azide 5 to 12-nitro-1, 15-pentadecanlactam 6 is the key step featured by direct ring expansion.
2004, 15(2): 171-174
Abstract:
Ethylene glycol phosphorochloridite 1 or catechol phosphorochloridite 2 reacted with isopropylidene derivatives of D-glucose, D-galactose, D-mannose and D-fructose, a series of glycosyl phosphites were obtained. These glycosyl phosphites form optically active complexes with simple Pt (Ⅱ) salts. Pt (Ⅱ) is coordinated to the phosphorus atom, most of the metal complexes are quite stable.
Ethylene glycol phosphorochloridite 1 or catechol phosphorochloridite 2 reacted with isopropylidene derivatives of D-glucose, D-galactose, D-mannose and D-fructose, a series of glycosyl phosphites were obtained. These glycosyl phosphites form optically active complexes with simple Pt (Ⅱ) salts. Pt (Ⅱ) is coordinated to the phosphorus atom, most of the metal complexes are quite stable.
2004, 15(2): 175-178
Abstract:
Three polymerizable vinyl guaifenesin esters with different acyl donor carbon chain lengths (C4, C6, C10) were regioselectivly synthesized by an alkaline protease from Bacillus subtilis in pyridine at 50℃ for 1, 3, 5 days respectively.
Three polymerizable vinyl guaifenesin esters with different acyl donor carbon chain lengths (C4, C6, C10) were regioselectivly synthesized by an alkaline protease from Bacillus subtilis in pyridine at 50℃ for 1, 3, 5 days respectively.
2004, 15(2): 179-180
Abstract:
Substituted 3H-indole modified β-cyclodextrin (β-CD) was prepared by the reaction of 6-deoxy-6-[(2-aminoethyl)amino]-β-CD (CDen) with 2-[(p-amino)phenyl]-3, 3-dimethyl-5-car-boxyl-3H-indole (substituted 3H-indole) in the presence of dicyclohexylcarbodiimide (DCC) and 1-hydroxybenzotriazole (HOBt). The product has been characterized by means of elemental analysis, MS and 1H NMR.
Substituted 3H-indole modified β-cyclodextrin (β-CD) was prepared by the reaction of 6-deoxy-6-[(2-aminoethyl)amino]-β-CD (CDen) with 2-[(p-amino)phenyl]-3, 3-dimethyl-5-car-boxyl-3H-indole (substituted 3H-indole) in the presence of dicyclohexylcarbodiimide (DCC) and 1-hydroxybenzotriazole (HOBt). The product has been characterized by means of elemental analysis, MS and 1H NMR.
2004, 15(2): 181-182
Abstract:
2-Chloro-5-methylpyridine can be effectively isolated from its isomer 2-chloro-3-methyl-pyridine in the form of Cu2+ complex. After hydrolyzing the complex, it can be obtained in more than 99.1% purity.
2-Chloro-5-methylpyridine can be effectively isolated from its isomer 2-chloro-3-methyl-pyridine in the form of Cu2+ complex. After hydrolyzing the complex, it can be obtained in more than 99.1% purity.
2004, 15(2): 183-186
Abstract:
The novel one-dimensional coordination polymer {[Cu(L)2(H2O)]·2BF4·6H2O}∞[1, L=1, 2-bis(4-pyridinecarboxamido)ethane] was synthesized as single crystals and characterized by means of X-ray diffraction analysis, elemental analysis, IR spectroscopy and TG measurement. Structure 1 consists of looped chains. In addition, linked by hydrogen bonds, the one-dimensional chains were transformed into three-dimensional framework, which shows channels filled with anions and uncoordinated water molecules.
The novel one-dimensional coordination polymer {[Cu(L)2(H2O)]·2BF4·6H2O}∞[1, L=1, 2-bis(4-pyridinecarboxamido)ethane] was synthesized as single crystals and characterized by means of X-ray diffraction analysis, elemental analysis, IR spectroscopy and TG measurement. Structure 1 consists of looped chains. In addition, linked by hydrogen bonds, the one-dimensional chains were transformed into three-dimensional framework, which shows channels filled with anions and uncoordinated water molecules.
2004, 15(2): 187-190
Abstract:
A polysaccharide, isolated from Centella asiatica, was a complicated arabinogalactan (AG), which contained a little α-(1→4)-linked GalpA and α-(1→2)-linked Rhap residues. Based on composition and methylation analyses, partial acid hydrolysis, periodate oxidation, NMR, ESI-MS experiments, it was shown to have a backbone of β-(1→3)-linked D-Galp residues, with heavily branched side chains. Araf residues were linked to O-3 of (1→3, 6)-linked Galp residues.
A polysaccharide, isolated from Centella asiatica, was a complicated arabinogalactan (AG), which contained a little α-(1→4)-linked GalpA and α-(1→2)-linked Rhap residues. Based on composition and methylation analyses, partial acid hydrolysis, periodate oxidation, NMR, ESI-MS experiments, it was shown to have a backbone of β-(1→3)-linked D-Galp residues, with heavily branched side chains. Araf residues were linked to O-3 of (1→3, 6)-linked Galp residues.
2004, 15(2): 191-193
Abstract:
A dimer of styrylpyrone derivative, leiocarpin E (1), was isolated from the bark of Goniothalamus leiocarpus. Its structures was elucidated by means of spectral and chemical methods. The cytotoxicity of leiocarpin E against HL-60 cells was tested.
A dimer of styrylpyrone derivative, leiocarpin E (1), was isolated from the bark of Goniothalamus leiocarpus. Its structures was elucidated by means of spectral and chemical methods. The cytotoxicity of leiocarpin E against HL-60 cells was tested.
2004, 15(2): 194-196
Abstract:
A new stigmasterol 3β, 7α, 22-trihydoxystigmast-5-ene (1) and a new eremophilen-olide 8α-methoxy-6β-angeloyloxyeremophil-7(11)-en-8β, 12-olide-14-oic acid (2) were isolated from Ligularia dolichobotrys Diels. Their structures were deduced on the basis of spectral data.
A new stigmasterol 3β, 7α, 22-trihydoxystigmast-5-ene (1) and a new eremophilen-olide 8α-methoxy-6β-angeloyloxyeremophil-7(11)-en-8β, 12-olide-14-oic acid (2) were isolated from Ligularia dolichobotrys Diels. Their structures were deduced on the basis of spectral data.
2004, 15(2): 197-199
Abstract:
Two new dihydroagarofuran sesquiterpenes with a novel substitution pattern:1α-(α-methyl)-butanoyl-2α, 15-diacetoxy-4β-hydroxy-9β-(β-)furancarboxy-β-dihydroagarofuran (1) and 1α, 2α-di-(α-methyl)-butanoyl-4β-hydroxy-9β-(β-)furancarboxy-15-acetoxy-β-dihydro-agaro-furan (2) were isolated from Euonymus nanoides. Their structures were elucidated by means of 1H and 13C NMR spectroscopic studies, including 2D NMR technique.
Two new dihydroagarofuran sesquiterpenes with a novel substitution pattern:1α-(α-methyl)-butanoyl-2α, 15-diacetoxy-4β-hydroxy-9β-(β-)furancarboxy-β-dihydroagarofuran (1) and 1α, 2α-di-(α-methyl)-butanoyl-4β-hydroxy-9β-(β-)furancarboxy-15-acetoxy-β-dihydro-agaro-furan (2) were isolated from Euonymus nanoides. Their structures were elucidated by means of 1H and 13C NMR spectroscopic studies, including 2D NMR technique.
2004, 15(2): 200-203
Abstract:
Three new C21 steroidal glycosides named komaroside A, komaroside B, komaroside C were isolated from the ethanolic extract of the roots of Cynanchum komarovii Al.Iljinski (Asclepiadaceae), their structures were determined by physiochemical and spectroscopic analysis.
Three new C21 steroidal glycosides named komaroside A, komaroside B, komaroside C were isolated from the ethanolic extract of the roots of Cynanchum komarovii Al.Iljinski (Asclepiadaceae), their structures were determined by physiochemical and spectroscopic analysis.
2004, 15(2): 204-207
Abstract:
Redox mechanism of ferrocene, acetylferrocene, ferrocenyl cinnamenyl ketone at a platinum electrode was studied with cyclic voltammetry (CV) and in-situ Fourier transform infrared (FTIR) spectroelectrochemistry. The IR bands in the range of 2000-1000 cm-1 attributed to the stretching and ring vibrations of these materials show the main spectral changes in the processes.
Redox mechanism of ferrocene, acetylferrocene, ferrocenyl cinnamenyl ketone at a platinum electrode was studied with cyclic voltammetry (CV) and in-situ Fourier transform infrared (FTIR) spectroelectrochemistry. The IR bands in the range of 2000-1000 cm-1 attributed to the stretching and ring vibrations of these materials show the main spectral changes in the processes.
2004, 15(2): 208-211
Abstract:
Naphthol green B was used, for the first time, as a new mediator in an amperometric glucose biosensor. It is a good mediator, promoting electron transfer from glucose oxidase to graphite electrode. The biosensor shows high sensitivity to glucose at low potential with response time of 30 seconds. The linear range is from 1.5 to 18 μmol/L glucose with detection limit of 0.5 μmol/L glucose.
Naphthol green B was used, for the first time, as a new mediator in an amperometric glucose biosensor. It is a good mediator, promoting electron transfer from glucose oxidase to graphite electrode. The biosensor shows high sensitivity to glucose at low potential with response time of 30 seconds. The linear range is from 1.5 to 18 μmol/L glucose with detection limit of 0.5 μmol/L glucose.
2004, 15(2): 212-213
Abstract:
A method for determination of alkaline phosphatase (ALP) in BALB/c mouse fetal liver stromal cells has been described based on the catalytic reaction. After the cell extract is incubated with the substrate disodium phenyl phosphate, the reaction product phenol generated by ALP is determined by capillary electrophoresis with electrochemical detection.
A method for determination of alkaline phosphatase (ALP) in BALB/c mouse fetal liver stromal cells has been described based on the catalytic reaction. After the cell extract is incubated with the substrate disodium phenyl phosphate, the reaction product phenol generated by ALP is determined by capillary electrophoresis with electrochemical detection.
2004, 15(2): 214-215
Abstract:
The activity of horseradish peroxidase at β-cyclodextrin polymer was imaged by scanning electrochemical microscopy using 3, 3', 5, 5'-tetramethylbenzide and H2O2 as the substrates.
The activity of horseradish peroxidase at β-cyclodextrin polymer was imaged by scanning electrochemical microscopy using 3, 3', 5, 5'-tetramethylbenzide and H2O2 as the substrates.
2004, 15(2): 216-219
Abstract:
Two novel polyoxometalates containing pharmaceutical component amantadine, formulated with (C10H18N)5PMo12O40Cl2·5H2O (I) and (C10H18N)6As2Mo18O62·6CH3CN·6H2O(II) were first synthesized and characterized by IR, UV-Vis spectra and X-ray diffraction. Structural analyses of I and II suggested that polyanions in these compounds were reserved their Keggin or Dawson structures and were linked to amantadine through electrostatic interaction and hydrogen bonding.
Two novel polyoxometalates containing pharmaceutical component amantadine, formulated with (C10H18N)5PMo12O40Cl2·5H2O (I) and (C10H18N)6As2Mo18O62·6CH3CN·6H2O(II) were first synthesized and characterized by IR, UV-Vis spectra and X-ray diffraction. Structural analyses of I and II suggested that polyanions in these compounds were reserved their Keggin or Dawson structures and were linked to amantadine through electrostatic interaction and hydrogen bonding.
2004, 15(2): 220-223
Abstract:
The complex of[As2V8IVV2VO26]·8H2O 1 has been hydrothermally synthesized and characterized by IR, elemental analysis, EPR, TGA and single crystal X-ray diffraction analysis. The structure features of 1 are described.
The complex of[As2V8IVV2VO26]·8H2O 1 has been hydrothermally synthesized and characterized by IR, elemental analysis, EPR, TGA and single crystal X-ray diffraction analysis. The structure features of 1 are described.
2004, 15(2): 224-227
Abstract:
The relation of the isoelectric point (IEP) and the point of zero net charge (PZNC) of the hydrotalcite-like compounds was discussed. It was found that the IEP does not equal to the PZNC and the IEP is higher than the PZNC. The structural positive charges existing in the HTlc, which cause the difference between the IEP and the PZNC. The effects of the structural positive charges of the HTlc on its IEP and PZNC are the same as the specific adsorption of metal cations.
The relation of the isoelectric point (IEP) and the point of zero net charge (PZNC) of the hydrotalcite-like compounds was discussed. It was found that the IEP does not equal to the PZNC and the IEP is higher than the PZNC. The structural positive charges existing in the HTlc, which cause the difference between the IEP and the PZNC. The effects of the structural positive charges of the HTlc on its IEP and PZNC are the same as the specific adsorption of metal cations.
2004, 15(2): 228-230
Abstract:
The colloidal crystal template or opal with a closed-packed face centered cubic (fcc) lattice, was prepared from monodisperse polystyrene (PS) spheres by gravity sedimentation. The template was used for the generation of photonic crystal. The template provided void space for infiltration of liquid precursor composed of titanium butyloxide, barium acetate, ethanol, and acetic acid. The opal composite was hydrolyzed, dried, sintered by heating for completely removing PS spheres to form BaTiO3 photonic crystals with inverse opal structure. The PS spheres were replaced by air spheres, which interconnected each other through the windows on the BaTiO3 wall. So both the BaTiO3 wall and air void constitute continuous phases.
The colloidal crystal template or opal with a closed-packed face centered cubic (fcc) lattice, was prepared from monodisperse polystyrene (PS) spheres by gravity sedimentation. The template was used for the generation of photonic crystal. The template provided void space for infiltration of liquid precursor composed of titanium butyloxide, barium acetate, ethanol, and acetic acid. The opal composite was hydrolyzed, dried, sintered by heating for completely removing PS spheres to form BaTiO3 photonic crystals with inverse opal structure. The PS spheres were replaced by air spheres, which interconnected each other through the windows on the BaTiO3 wall. So both the BaTiO3 wall and air void constitute continuous phases.
2004, 15(2): 231-233
Abstract:
Carbon nanotubes (CNTs) were prepared by decomposition of C2H2 over newly developed LaCu0.2Ni0.8Ox in the temperature range from 600 to 850℃. The effect of the reaction temperature on the yield of CNTs was investigated in detail. At 680℃, the yield of CNTs reaches 17 g/g.catal. or so. The morphology of CNTs was examined by TEM. The diameter of CNTs rangs from 9 nm to 14 nm.
Carbon nanotubes (CNTs) were prepared by decomposition of C2H2 over newly developed LaCu0.2Ni0.8Ox in the temperature range from 600 to 850℃. The effect of the reaction temperature on the yield of CNTs was investigated in detail. At 680℃, the yield of CNTs reaches 17 g/g.catal. or so. The morphology of CNTs was examined by TEM. The diameter of CNTs rangs from 9 nm to 14 nm.
2004, 15(2): 234-237
Abstract:
A novel polymer electrolyte with the formula of Li2B4O7-PVA for lithium-ion battery was synthesized and its ion conductivity and mechanical properties were also tested. It is found that the conductivity of the prepared polymer electrolytes is higher than that of LiClO4/PEO or LiClO4/EC-DMC by two or three orders in magnitude and a large delocalized bond formed in Li2B4O7-PVA lead to transportation of Li ion easier, this electrolyte possesses high thermo-stability and can be used under 200℃.
A novel polymer electrolyte with the formula of Li2B4O7-PVA for lithium-ion battery was synthesized and its ion conductivity and mechanical properties were also tested. It is found that the conductivity of the prepared polymer electrolytes is higher than that of LiClO4/PEO or LiClO4/EC-DMC by two or three orders in magnitude and a large delocalized bond formed in Li2B4O7-PVA lead to transportation of Li ion easier, this electrolyte possesses high thermo-stability and can be used under 200℃.
2004, 15(2): 238-241
Abstract:
Barium lithium fluoride nanocrystals were synthesized in cetyltrimethylammonium bromide (CTAB)/2-octanol/water microemulsion systems. The impurity peaks in XRD patterns were not determined. The result of SEM confirmed that the average sizes and shape of the BaLiF3 nanocrystals. The formation of BaLiF3 and particles size were strongly affected by water content. With increasing water content and reaction times, the size of the particle increases.Meanwhile, the solvent was also found to play a key role in the synthesis of the BaLiF3nanocrystals.
Barium lithium fluoride nanocrystals were synthesized in cetyltrimethylammonium bromide (CTAB)/2-octanol/water microemulsion systems. The impurity peaks in XRD patterns were not determined. The result of SEM confirmed that the average sizes and shape of the BaLiF3 nanocrystals. The formation of BaLiF3 and particles size were strongly affected by water content. With increasing water content and reaction times, the size of the particle increases.Meanwhile, the solvent was also found to play a key role in the synthesis of the BaLiF3nanocrystals.
2004, 15(2): 242-245
Abstract:
In this paper, the surface imprinted cross-linked polystyrene beads were prepared via suspension polymerization with styrene (St), divinylbezene (DVB), polyvinyl alcohol (PVA1788), the mixture of Span 85 and xylene or the mixture of Span 85 and paraffin as monomer, cross-linking agent, dispersion stabilizer and templates, respectively. The results indicate that there are dense cavities on the surface of beads, and the diameter and density of cavity are related with the composition and amount of emulsion template. The forming mechanism of cavity from thermodynamics and dynamics was proposed.
In this paper, the surface imprinted cross-linked polystyrene beads were prepared via suspension polymerization with styrene (St), divinylbezene (DVB), polyvinyl alcohol (PVA1788), the mixture of Span 85 and xylene or the mixture of Span 85 and paraffin as monomer, cross-linking agent, dispersion stabilizer and templates, respectively. The results indicate that there are dense cavities on the surface of beads, and the diameter and density of cavity are related with the composition and amount of emulsion template. The forming mechanism of cavity from thermodynamics and dynamics was proposed.
2004, 15(2): 246-249
Abstract:
The possible stable structures of substituted fullerene C26BN formed on the initial C28 cage with Td symmetry have been systematically studied on UHF/3-21g level with constrained symmetry(Cs or C1), the charge and multiplicity of all the isomers are zero and five, respectively. The geometry optimization and the vibrational frequencies analysis were performed on the same level with constrained symmetry(Cs or C1). The results show that the most stable isomer of C26BN is formed by boron and nitrogen atoms doping at 5, 2-sites.
The possible stable structures of substituted fullerene C26BN formed on the initial C28 cage with Td symmetry have been systematically studied on UHF/3-21g level with constrained symmetry(Cs or C1), the charge and multiplicity of all the isomers are zero and five, respectively. The geometry optimization and the vibrational frequencies analysis were performed on the same level with constrained symmetry(Cs or C1). The results show that the most stable isomer of C26BN is formed by boron and nitrogen atoms doping at 5, 2-sites.
2004, 15(2): 250-252
Abstract:
Three new isomers of FCH2CP system, F(H)CCPH (1), F-cCPC-H(H) (2) and F-cCC(H)P-H (3), are predicted by means of B3LYP and CCSD(T) (single-point) methods with 6-311++G(d, p) and 6-311++G(2df, 2p) basis sets, respectively. The three calculated isomers can isomerize into thermodynamically the most stable species F-cPC(H)C-H, which has been suggested in previous theoretical studies, with relatively higher reaction barriers. In view of their higher thermodynamic and kinetic stability, we believe that the three species can be detected in future experiments.
Three new isomers of FCH2CP system, F(H)CCPH (1), F-cCPC-H(H) (2) and F-cCC(H)P-H (3), are predicted by means of B3LYP and CCSD(T) (single-point) methods with 6-311++G(d, p) and 6-311++G(2df, 2p) basis sets, respectively. The three calculated isomers can isomerize into thermodynamically the most stable species F-cPC(H)C-H, which has been suggested in previous theoretical studies, with relatively higher reaction barriers. In view of their higher thermodynamic and kinetic stability, we believe that the three species can be detected in future experiments.
