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1997 Volume 14 Issue 4
1997, 14(4): 1-5
Abstract:
A synthetic method of LnH2salen complexes was described and a series of binuclear complexes were obtained. The complexes were characterized by elemental analysis, TG-DTA, UV-IR spectroscopy, magnetic susceptibility, 1H,13C NMR measurements and the 13C-spin-lattic relaxation time was investigated for elucidation of their complexation. The composition of the complexes obtained were confirmed as[Ln2(H2salen)3(NO3)4](NO3)2·3H2O, where Ln=La, Pr, Nd, Sm, Gd, Tb, Er, Yb, and Y. A possible structure was suggested and the catalytic activity of the complexes for MMA polymerization was discussed.
A synthetic method of LnH2salen complexes was described and a series of binuclear complexes were obtained. The complexes were characterized by elemental analysis, TG-DTA, UV-IR spectroscopy, magnetic susceptibility, 1H,13C NMR measurements and the 13C-spin-lattic relaxation time was investigated for elucidation of their complexation. The composition of the complexes obtained were confirmed as[Ln2(H2salen)3(NO3)4](NO3)2·3H2O, where Ln=La, Pr, Nd, Sm, Gd, Tb, Er, Yb, and Y. A possible structure was suggested and the catalytic activity of the complexes for MMA polymerization was discussed.
1997, 14(4): 6-9
Abstract:
The substituted tungstosilicate complexes T-NamHn[SiW9M3(H2O)3O37]·16H2O (M=Co(Ⅱ), Ni(Ⅱ), V(Ⅴ)) were synthesized and characterized by IR, UV, ICP, TG-DTA, EPR and XPS. The conductivity of co complex was above 1×10-3 S/cm at room temperature and 1×10-2 S/cm at 343 K. The magnetic susceptibility data obtained in the range of 75~300 K have fitted with J and g, based on the spin hamiltonian H=-2
Jij·Si·Sj.
The substituted tungstosilicate complexes T-NamHn[SiW9M3(H2O)3O37]·16H2O (M=Co(Ⅱ), Ni(Ⅱ), V(Ⅴ)) were synthesized and characterized by IR, UV, ICP, TG-DTA, EPR and XPS. The conductivity of co complex was above 1×10-3 S/cm at room temperature and 1×10-2 S/cm at 343 K. The magnetic susceptibility data obtained in the range of 75~300 K have fitted with J and g, based on the spin hamiltonian H=-2
Jij·Si·Sj.
1997, 14(4): 10-13
Abstract:
Five asymmetric crown telluracarbocyanines were prepared. The visible absorption spectra and the "Brooker diviation" of four of them have been studied. The method of reduction and acylation of 4-nicrobenzo-15-crown-5 has been improved, making the synthesis of the asymmetric crown ether telluracarbocyanine dyes quite convenient and easy.
Five asymmetric crown telluracarbocyanines were prepared. The visible absorption spectra and the "Brooker diviation" of four of them have been studied. The method of reduction and acylation of 4-nicrobenzo-15-crown-5 has been improved, making the synthesis of the asymmetric crown ether telluracarbocyanine dyes quite convenient and easy.
1997, 14(4): 14-17
Abstract:
The hydrous iron oxide/quartz sand adsorbent for water and wastewater treatment was prepared by repeat precipitation and heating vaporization. The surface morphologies of the adsorbent were observed by SEM. The binding property of iron oxide on the surface of adsorbent as well as the adsorption and desorption of metallic ions were studied. Various surface morphologies of the adsorbent were found as prepared by evaporization method. Both binding property of iron oxide on the adsorbent either in acid solution or under shaking and the adsorption effectiveness of the adsorbent to Cd2+ and Cr3+ are quite good.
The hydrous iron oxide/quartz sand adsorbent for water and wastewater treatment was prepared by repeat precipitation and heating vaporization. The surface morphologies of the adsorbent were observed by SEM. The binding property of iron oxide on the surface of adsorbent as well as the adsorption and desorption of metallic ions were studied. Various surface morphologies of the adsorbent were found as prepared by evaporization method. Both binding property of iron oxide on the adsorbent either in acid solution or under shaking and the adsorption effectiveness of the adsorbent to Cd2+ and Cr3+ are quite good.
1997, 14(4): 18-20
Abstract:
Ultrafine particles of polypyrrole were prepared in two phase system of pyrrole with O/W microemulsion through polymerization. Polypyrrole with particle size less than 10 nm was obtained; it is spherical and shows a good conductivity as measured in THF.
Ultrafine particles of polypyrrole were prepared in two phase system of pyrrole with O/W microemulsion through polymerization. Polypyrrole with particle size less than 10 nm was obtained; it is spherical and shows a good conductivity as measured in THF.
1997, 14(4): 21-24
Abstract:
Ni-Mo-PTFE composite electrode was obtained from a mixture containing 0.22 mol/L NiSO4·6H2O, 0.06 mol/L Na2MoO4·2H2O, 0.3 mol/L Na3C6H5O7·2H2O, 30 g/L PTFE and 0.1 g/L FC-400 surfactant (pH=9) in 45℃ with current density of 10 mA/cm2. XRD of the composite deposit reveals that it is a face centered cubic solid solution and exhibits (111) preferred orientation. X-ray photoelectron energy spectra of the composite deposit indicate that fluorine exists in form of (CF2)n. SEM showed the larger surface roughness of the electrode. The mechanism of Ni-Mo-PTFE composite electrodeposition has been discussed. The cyclic voltammetric study showed that the electrocatalytic activity of Ni-Mo-PTFE electrode on methanol oxidation is bigger than that of Ni-Mo electrode.
Ni-Mo-PTFE composite electrode was obtained from a mixture containing 0.22 mol/L NiSO4·6H2O, 0.06 mol/L Na2MoO4·2H2O, 0.3 mol/L Na3C6H5O7·2H2O, 30 g/L PTFE and 0.1 g/L FC-400 surfactant (pH=9) in 45℃ with current density of 10 mA/cm2. XRD of the composite deposit reveals that it is a face centered cubic solid solution and exhibits (111) preferred orientation. X-ray photoelectron energy spectra of the composite deposit indicate that fluorine exists in form of (CF2)n. SEM showed the larger surface roughness of the electrode. The mechanism of Ni-Mo-PTFE composite electrodeposition has been discussed. The cyclic voltammetric study showed that the electrocatalytic activity of Ni-Mo-PTFE electrode on methanol oxidation is bigger than that of Ni-Mo electrode.
1997, 14(4): 25-28
Abstract:
The efficiency of penetration enhancers for niclosamide has been studied using double-cell skin permeation system. It was found that oleic acid was a good enhancer for niclosamide and was more efficient than azone. Azone showed a synergism with oleic acid or propylene glycol. It was also demonstrated that niclosamide could be used as a long-lasting liniment. The mechanism of the effect of azone and oleic acid has been investigated by IR and DSC techniques.
The efficiency of penetration enhancers for niclosamide has been studied using double-cell skin permeation system. It was found that oleic acid was a good enhancer for niclosamide and was more efficient than azone. Azone showed a synergism with oleic acid or propylene glycol. It was also demonstrated that niclosamide could be used as a long-lasting liniment. The mechanism of the effect of azone and oleic acid has been investigated by IR and DSC techniques.
1997, 14(4): 29-32
Abstract:
The performances such as the discharge capacity, activation, electrocatalytic activity and high-rate dischargeability of MH electrodes were improved by the chemical reduction in an alkaline solution containing a reductant KBH4. MH-Ni batteries assembled with KBH4-treated MH electrodes as negative electrodes were sealed formated. The performances of the batteries by sealed formation were superior to that of the batteries by open formation. The capacity approached 1150 mAh. High-rate dischargeability (at 5 C) was above 80% and the capacity at -18℃ (0.2 C) was 90% of that at room tempearture (0.2 C). The cyclic life of the MH-Ni battery at 1 C (100% DOD) increased from 100 cycles to 200 cycles and more.
The performances such as the discharge capacity, activation, electrocatalytic activity and high-rate dischargeability of MH electrodes were improved by the chemical reduction in an alkaline solution containing a reductant KBH4. MH-Ni batteries assembled with KBH4-treated MH electrodes as negative electrodes were sealed formated. The performances of the batteries by sealed formation were superior to that of the batteries by open formation. The capacity approached 1150 mAh. High-rate dischargeability (at 5 C) was above 80% and the capacity at -18℃ (0.2 C) was 90% of that at room tempearture (0.2 C). The cyclic life of the MH-Ni battery at 1 C (100% DOD) increased from 100 cycles to 200 cycles and more.
1997, 14(4): 33-36
Abstract:
The synthesis of polysiloxane-polyacrylate IPN coating was investigated. IR, TG, GPC and SEM tests indicate that the emulsion can be used as an efflorescenceproof material to protect the stone sculpture along hills with its excellent performance of transparency, high hardness and adhesion, resistance to acid-settlement and thermostable-aging, perviousness to gas and moisture. The coating can be used to avoid the presumed "protective destroy" created by using the coating based on single polysiloxane or polyacrylate.
The synthesis of polysiloxane-polyacrylate IPN coating was investigated. IR, TG, GPC and SEM tests indicate that the emulsion can be used as an efflorescenceproof material to protect the stone sculpture along hills with its excellent performance of transparency, high hardness and adhesion, resistance to acid-settlement and thermostable-aging, perviousness to gas and moisture. The coating can be used to avoid the presumed "protective destroy" created by using the coating based on single polysiloxane or polyacrylate.
1997, 14(4): 37-40
Abstract:
V-(U-Cyanoethylmercapto) propyltriethoxysilane has been synthesized from V-mercaptopropyltriethoxysilane via Michael addition with acrylonitrile in the presence of sodium ethoxide. The silicon monomer was hydrolyzed and immobilized by water and fumed silica, then reacted with potassium chloroplatinite in acetone to give the title complex. It has been found that the title complex is an effective catalyst for hydrosilylation of decene, dodecene, phenyl allyl ether, allyl glycidyl ether, etc. with triethoxysilane and can be reused several times without any noticeable loss of activity.
V-(U-Cyanoethylmercapto) propyltriethoxysilane has been synthesized from V-mercaptopropyltriethoxysilane via Michael addition with acrylonitrile in the presence of sodium ethoxide. The silicon monomer was hydrolyzed and immobilized by water and fumed silica, then reacted with potassium chloroplatinite in acetone to give the title complex. It has been found that the title complex is an effective catalyst for hydrosilylation of decene, dodecene, phenyl allyl ether, allyl glycidyl ether, etc. with triethoxysilane and can be reused several times without any noticeable loss of activity.
1997, 14(4): 41-45
Abstract:
The effects of the preparation conditions of Pd/C catalyst and the promoters on the catalytic property have been investigated. The influences of partial oxygen pressure and addition of nitrobenzene on the oxidative carbonylation of aniline to ethyl N-phenyl carbamate also have been tested. The Pd/C catalyst was characterized by XPS, TPR and in-situ IR techniques. A possible mechanism of the oxidative carbonylation of aniline catalyzed by Pd/C-NaI system in alcohol medium has been proposed.
The effects of the preparation conditions of Pd/C catalyst and the promoters on the catalytic property have been investigated. The influences of partial oxygen pressure and addition of nitrobenzene on the oxidative carbonylation of aniline to ethyl N-phenyl carbamate also have been tested. The Pd/C catalyst was characterized by XPS, TPR and in-situ IR techniques. A possible mechanism of the oxidative carbonylation of aniline catalyzed by Pd/C-NaI system in alcohol medium has been proposed.
1997, 14(4): 46-49
Abstract:
The annealing behaviour of irradiated polyethylene(PE) single crystals was studied with Mixed-Crystals IR spectroscopy, SAXS, WAXD and DSC. The results were:(1) There are both adjacent reentry folding and random stems in the PE single crystals, the former is predominant. (2) In the annealing below or at 90℃, reptation is the major molecular motion, and it leads to improvement of the crystal structure to limited extent; partial fusion and recrystalization are involved in the annealing at 105℃. (3) The crosslinking and damage in the crystal region caused by irradiation prevents the PE crystals from being improved.
The annealing behaviour of irradiated polyethylene(PE) single crystals was studied with Mixed-Crystals IR spectroscopy, SAXS, WAXD and DSC. The results were:(1) There are both adjacent reentry folding and random stems in the PE single crystals, the former is predominant. (2) In the annealing below or at 90℃, reptation is the major molecular motion, and it leads to improvement of the crystal structure to limited extent; partial fusion and recrystalization are involved in the annealing at 105℃. (3) The crosslinking and damage in the crystal region caused by irradiation prevents the PE crystals from being improved.
1997, 14(4): 50-54
Abstract:
Lyotropic liquid crystals formed from mixed surfactants perfluorooctanoic sodium/hexadecyltrimethyl ammonium bromide(OBS/CTAB-H2O-C4H9OH) have been used to determine the phase regions. The area of phase region in present system was bigger than that in CTAB-C4H9OH-H2O system. Some typical photographs were obtained by polarized light microscope. The geometrical dimensions were determined by small angle X-ray diffraction. The 2H NMR method together with liquid crystals' photographs were applied to determine the exact liquid crystals' structure.
Lyotropic liquid crystals formed from mixed surfactants perfluorooctanoic sodium/hexadecyltrimethyl ammonium bromide(OBS/CTAB-H2O-C4H9OH) have been used to determine the phase regions. The area of phase region in present system was bigger than that in CTAB-C4H9OH-H2O system. Some typical photographs were obtained by polarized light microscope. The geometrical dimensions were determined by small angle X-ray diffraction. The 2H NMR method together with liquid crystals' photographs were applied to determine the exact liquid crystals' structure.
1997, 14(4): 55-58
Abstract:
The phase diagram of the system of dodecyl carboxylic diethanolamine (DCD)/n-butanol (C4H9OH)/paraffin oil(LP)/water has been investigated. The phase structures of two points chosen from the liquid crystal phase region were determined by 2H NMR spectroscopy and polarized-light microscope. The wear scar widths and the vertical loads of the two samples on the surface of aluminium alloy were measured and compared with those of water, paraffin oil, n-butanol, paraffin oil+2%n-butanol, paraffin oil+2%diethanolamine and lithium grease. The results indicate that the frictional force of the lamellar liquid crystal in the direction parallel to the surface of the alloy aluminium is very small, and the lamellar liquid crystal appear to be a good lubricant.
The phase diagram of the system of dodecyl carboxylic diethanolamine (DCD)/n-butanol (C4H9OH)/paraffin oil(LP)/water has been investigated. The phase structures of two points chosen from the liquid crystal phase region were determined by 2H NMR spectroscopy and polarized-light microscope. The wear scar widths and the vertical loads of the two samples on the surface of aluminium alloy were measured and compared with those of water, paraffin oil, n-butanol, paraffin oil+2%n-butanol, paraffin oil+2%diethanolamine and lithium grease. The results indicate that the frictional force of the lamellar liquid crystal in the direction parallel to the surface of the alloy aluminium is very small, and the lamellar liquid crystal appear to be a good lubricant.
1997, 14(4): 59-62
Abstract:
Tetrabromobisphenol A antimony and aluminium was synthesized and characterized by elemental analysis, IR and 1H NMR spectroscopy. The results showed that the compound prepared has s high retardation efficiency and high smoke removing property for polyethylene and polyethylene oxide.
Tetrabromobisphenol A antimony and aluminium was synthesized and characterized by elemental analysis, IR and 1H NMR spectroscopy. The results showed that the compound prepared has s high retardation efficiency and high smoke removing property for polyethylene and polyethylene oxide.
1997, 14(4): 63-65
Abstract:
Three spin-labelling auxins have been synthesized by reaction of 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl(TMPO) with p-chlorophenoxyacetic acid, 1-naphthylacetic acid and 2,4-dichlorophenoxyacetic acid respectively. The structures of the labelling auxins were confirmed by IR, ESR/MS measurements and elemental analysis. The preliminary bioassays of the compounds indicated that they retain the original plant regulating property.
Three spin-labelling auxins have been synthesized by reaction of 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl(TMPO) with p-chlorophenoxyacetic acid, 1-naphthylacetic acid and 2,4-dichlorophenoxyacetic acid respectively. The structures of the labelling auxins were confirmed by IR, ESR/MS measurements and elemental analysis. The preliminary bioassays of the compounds indicated that they retain the original plant regulating property.
1997, 14(4): 66-69
Abstract:
Fourteen solid complexes of rare earth with iso-nicotinic acid(HL) and 1,10-phenanthroline(Phen) have been synthesized and characterized. They are stable in air and have a general structural constitution of RE(Phen)L3, where RE=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y.
Fourteen solid complexes of rare earth with iso-nicotinic acid(HL) and 1,10-phenanthroline(Phen) have been synthesized and characterized. They are stable in air and have a general structural constitution of RE(Phen)L3, where RE=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y.
1997, 14(4): 70-73
Abstract:
Partial oxidation of methane to synthesis gas over Ni/T-Al2O3 promoted with rare earth oxides (La2O3, CeO2, Pr6O11 and Nd2O3) has been investigated by powder X-ray diffraction and XPS. The catalytic activity,size of nickel crystallite, stability and carbon deposition of the catalysts were examined. Addition of rare earth oxide greatly improved the stability of Ni/T-Al2O3. The SMSI between the active species of Ni and rare earth oxides depresses the growth and the migration of Ni, as well as the carbon deposition on the surface of the catalyst.
Partial oxidation of methane to synthesis gas over Ni/T-Al2O3 promoted with rare earth oxides (La2O3, CeO2, Pr6O11 and Nd2O3) has been investigated by powder X-ray diffraction and XPS. The catalytic activity,size of nickel crystallite, stability and carbon deposition of the catalysts were examined. Addition of rare earth oxide greatly improved the stability of Ni/T-Al2O3. The SMSI between the active species of Ni and rare earth oxides depresses the growth and the migration of Ni, as well as the carbon deposition on the surface of the catalyst.
1997, 14(4): 74-76
Abstract:
KSmLaF6 was synthesized by reducing Sm0.5La0.5F3 with potassium vapor at 300℃ or 420℃. The new compound has two phases:the low-temperature phase is trigonal crystal system with lattice parameters a=0.6493(2) nm, c=0.3777(1) nm, c/a=0.582, Z=1, sapce group P3; and the high-temperature phase is cubic crystal system with lattice parameters a=0.5873(3) nm, Z=4/3, space group Fm3m.
KSmLaF6 was synthesized by reducing Sm0.5La0.5F3 with potassium vapor at 300℃ or 420℃. The new compound has two phases:the low-temperature phase is trigonal crystal system with lattice parameters a=0.6493(2) nm, c=0.3777(1) nm, c/a=0.582, Z=1, sapce group P3; and the high-temperature phase is cubic crystal system with lattice parameters a=0.5873(3) nm, Z=4/3, space group Fm3m.
1997, 14(4): 77-79
Abstract:
TiO2/Pt/glass and TiO2/glass thin films in nanocrystalline have been prepared by sol-gel method and their structures and elctrochemically assisted photocatalysis have been examined. The results of electrochemically assisted photocatalytic degradation of dye solution by thin films indicate that the photocalytic activities of TiO2/Pt/glass thin films are higher than that of TiO2/glass thin films. Also, a more higher photocatalytic activity of TiO2/Pt/glass thin films can be achieved when an anodic bias is applied, and it increses with the increase of anodic bias. Forthermore, light showed effects on the photocatalytic activity of the thin film.
TiO2/Pt/glass and TiO2/glass thin films in nanocrystalline have been prepared by sol-gel method and their structures and elctrochemically assisted photocatalysis have been examined. The results of electrochemically assisted photocatalytic degradation of dye solution by thin films indicate that the photocalytic activities of TiO2/Pt/glass thin films are higher than that of TiO2/glass thin films. Also, a more higher photocatalytic activity of TiO2/Pt/glass thin films can be achieved when an anodic bias is applied, and it increses with the increase of anodic bias. Forthermore, light showed effects on the photocatalytic activity of the thin film.
1997, 14(4): 80-82
Abstract:
Ultrafine powder of T-Fe2O3 doped with antimony has been prepared by a novel oxidation-coprecipitation method. The products have been characterized by XRD, TEM, and their specific areas have been determined by front chromatography. The results showed that the powder prepared by this method has smaller mean particle size and larger specific area than that obtained by chemical coprecipitation.Ultrafine powder of T-Fe2O3 doped with Sn and Sb has also been prepared. The gas-sensitive ceramic units fabricated with powder prepared by the new method has been found to have much lower electrical resistance in air.
Ultrafine powder of T-Fe2O3 doped with antimony has been prepared by a novel oxidation-coprecipitation method. The products have been characterized by XRD, TEM, and their specific areas have been determined by front chromatography. The results showed that the powder prepared by this method has smaller mean particle size and larger specific area than that obtained by chemical coprecipitation.Ultrafine powder of T-Fe2O3 doped with Sn and Sb has also been prepared. The gas-sensitive ceramic units fabricated with powder prepared by the new method has been found to have much lower electrical resistance in air.
1997, 14(4): 83-84
Abstract:
The hard elasticity of polypropylene hollow fiber can be obtained on crystallization under high stress after heat treatment. The factors affecting the hard elasticity of the fiber are studied through SEM, WAXD and strain-stress tests.
The hard elasticity of polypropylene hollow fiber can be obtained on crystallization under high stress after heat treatment. The factors affecting the hard elasticity of the fiber are studied through SEM, WAXD and strain-stress tests.
1997, 14(4): 85-87
Abstract:
Surface oxygen species of Pd catalysts on different supports were investigated by O2-TPD-MS, TPR techniques. It was found that as a support. TiO2 showed better desorption and regeneration ability of surface oxygen than Al2O3 and CeO2. The reducibility of Pd catalyst was found to be in cerrespondence with its surface oxygen departure.
Surface oxygen species of Pd catalysts on different supports were investigated by O2-TPD-MS, TPR techniques. It was found that as a support. TiO2 showed better desorption and regeneration ability of surface oxygen than Al2O3 and CeO2. The reducibility of Pd catalyst was found to be in cerrespondence with its surface oxygen departure.
1997, 14(4): 88-90
Abstract:
A chiral complex, in situ prepared from (-)-quinine and CoCl2 was used as catalyst for asymmetric reduction of aromatic prochiral ketones:p-R2C6H4COR1(R1, R2 shown in Tab.1) and some products with moderate enantiomeric excesses were obtained. Effects of KBH4 and LiAlH4 as reductant and reaction temperature and time on the reaction were investigated.
A chiral complex, in situ prepared from (-)-quinine and CoCl2 was used as catalyst for asymmetric reduction of aromatic prochiral ketones:p-R2C6H4COR1(R1, R2 shown in Tab.1) and some products with moderate enantiomeric excesses were obtained. Effects of KBH4 and LiAlH4 as reductant and reaction temperature and time on the reaction were investigated.
1997, 14(4): 91-93
Abstract:
PVC has been dehydrochlorinated by alkali alkoxide in the presence of poly(vinyl butyral)(PVB). Effects of time, reagents and PVB on the reaction have been studied. The solution and product was analyzed by UV-Vis spectrophotometry and FTIR. A highly dehydrochlorinated PVC and stable product with long trans-(CH)x chain sequences has been found.
PVC has been dehydrochlorinated by alkali alkoxide in the presence of poly(vinyl butyral)(PVB). Effects of time, reagents and PVB on the reaction have been studied. The solution and product was analyzed by UV-Vis spectrophotometry and FTIR. A highly dehydrochlorinated PVC and stable product with long trans-(CH)x chain sequences has been found.
1997, 14(4): 94-95
Abstract:
A novel diazo photo-sensitive reagent 3-methyl-4-pyrrolidinylbenzenediazonium zinc chloride double salt(Ⅲ) was synthesized from 2-methyl-4-nitroaniline as a starting material. The title compound and the intermediate N-(2-methyl-4-nitrophenyl) pyrrolidine(Ⅱ) were identified by UV, IR, 1H NMR spectra and elemental analysis.
A novel diazo photo-sensitive reagent 3-methyl-4-pyrrolidinylbenzenediazonium zinc chloride double salt(Ⅲ) was synthesized from 2-methyl-4-nitroaniline as a starting material. The title compound and the intermediate N-(2-methyl-4-nitrophenyl) pyrrolidine(Ⅱ) were identified by UV, IR, 1H NMR spectra and elemental analysis.
1997, 14(4): 96-98
Abstract:
The synthetic method of 1,9-diazido-2,2,8,8-tetranitro-4,6-dioxanonane has been studied. The synthesis becomes much easier and more efficient by use of a triflate instead of a tosylate. The effect of the leaving groups on the azidation was also discussed and the explosive properties of the title compound were evaluated.
The synthetic method of 1,9-diazido-2,2,8,8-tetranitro-4,6-dioxanonane has been studied. The synthesis becomes much easier and more efficient by use of a triflate instead of a tosylate. The effect of the leaving groups on the azidation was also discussed and the explosive properties of the title compound were evaluated.
1997, 14(4): 99-101
Abstract:
The graphite furnace atomic absorption method with praphite probe has been used satisfactorily in determination of trace lead in hair. A linear relationship between the concentration of lead and peak area of absorbance was found, when the former is 0~250 μg/L. The method has a recovery of 98%~102%.
The graphite furnace atomic absorption method with praphite probe has been used satisfactorily in determination of trace lead in hair. A linear relationship between the concentration of lead and peak area of absorbance was found, when the former is 0~250 μg/L. The method has a recovery of 98%~102%.
1997, 14(4): 102-104
Abstract:
The effects of hydrazine as an additive on the specific area of Y2O3, when the latter is prapared by thermal decomposition method from yttrium oxalate, have been studied. The Y2O3 sample with specific area of 30 m2/g was obtained.
The effects of hydrazine as an additive on the specific area of Y2O3, when the latter is prapared by thermal decomposition method from yttrium oxalate, have been studied. The Y2O3 sample with specific area of 30 m2/g was obtained.
1997, 14(4): 105-107
Abstract:
A catalyst for V-butyrolactone production by liquid phase dehydrocyclization of 1,4-butanediol was prepared from Cu(NO3)2 and Zn(NO3)2 (exact in 1:1 mole ratio) by precipitation method. It showed a good catalytic activity for given reduction at 186~204℃ through H2 reaction at 240℃. The results of XRD, IR and DTA showed that the precursor has the same component and structure, as Aurichalcite.
A catalyst for V-butyrolactone production by liquid phase dehydrocyclization of 1,4-butanediol was prepared from Cu(NO3)2 and Zn(NO3)2 (exact in 1:1 mole ratio) by precipitation method. It showed a good catalytic activity for given reduction at 186~204℃ through H2 reaction at 240℃. The results of XRD, IR and DTA showed that the precursor has the same component and structure, as Aurichalcite.
1997, 14(4): 108-110
Abstract:
In a supporting electrolyte of HAc-NaAc, a sensitive derivative reduction peak of Tiapride was found by single-sweep oscillopolarography. The peak potential is -1.56 V(vs.SCE). The relationship between the peak current and the concentration of Tiapride is linear from 6.0×10-7~9.0×10-6 mol/L. The detection limit is 5.0×10-7 mol/L. The method was applied for determination of Tiapride in tablet with satisfactory results. The electrode process, reaction mechanism and polarographic behavior have been discussed.
In a supporting electrolyte of HAc-NaAc, a sensitive derivative reduction peak of Tiapride was found by single-sweep oscillopolarography. The peak potential is -1.56 V(vs.SCE). The relationship between the peak current and the concentration of Tiapride is linear from 6.0×10-7~9.0×10-6 mol/L. The detection limit is 5.0×10-7 mol/L. The method was applied for determination of Tiapride in tablet with satisfactory results. The electrode process, reaction mechanism and polarographic behavior have been discussed.
1997, 14(4): 111-113
Abstract:
Lithium (T-caralkoxyvinyl) (2-thienyl) mixed higher order cyanocuprate(3), prepared by addition reaction of ethyl propiolate with (n-C13H27) (2-thienyl) CuCNLi2(2), was coupled with cis-bromopropylene under Pd(PPh3)4, gaving ethyl 1-(Z-propylidene)-1E-hexadecenate(4). The title compound (±)-epilitsenolide C2, (3Z,4T,5T)-4-hydroxyl-5-methyl-3-tetradecylidene-tetrahydro-2-furanone(1) was then selectively synthesized through epoxidation of the diene ester with m-chloroperbenzoic acid as oxidant and stereospecific lactonation by acid catalysis. The title compound(1) showed E:Z > 98:2 and cis:trans > 96:4. The method proposed has advantages of short route and high yield. Thus a new efficient method is presented for stereo selective synthesis of 3-alkylidene-4,5-dihydro-4-hydroxy-5-methyl-2(3H)-furanones.
Lithium (T-caralkoxyvinyl) (2-thienyl) mixed higher order cyanocuprate(3), prepared by addition reaction of ethyl propiolate with (n-C13H27) (2-thienyl) CuCNLi2(2), was coupled with cis-bromopropylene under Pd(PPh3)4, gaving ethyl 1-(Z-propylidene)-1E-hexadecenate(4). The title compound (±)-epilitsenolide C2, (3Z,4T,5T)-4-hydroxyl-5-methyl-3-tetradecylidene-tetrahydro-2-furanone(1) was then selectively synthesized through epoxidation of the diene ester with m-chloroperbenzoic acid as oxidant and stereospecific lactonation by acid catalysis. The title compound(1) showed E:Z > 98:2 and cis:trans > 96:4. The method proposed has advantages of short route and high yield. Thus a new efficient method is presented for stereo selective synthesis of 3-alkylidene-4,5-dihydro-4-hydroxy-5-methyl-2(3H)-furanones.
1997, 14(4): 114-116
Abstract:
The change of surface, morphology and surface function group of carbon fiber after treatment with mixed acid (15%KClO3+40%H2SO4) has been studied by XPS, spectrophotometry. Raman spectrometry and X-ray diffractometry. Acid treatment showed an obvious possitive effect on the chemical modification of carbon fiber surface.
The change of surface, morphology and surface function group of carbon fiber after treatment with mixed acid (15%KClO3+40%H2SO4) has been studied by XPS, spectrophotometry. Raman spectrometry and X-ray diffractometry. Acid treatment showed an obvious possitive effect on the chemical modification of carbon fiber surface.
