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2000 Volume 17 Issue 2
2000, 17(2): 117-120
Abstract:
The hydrolysis of acrylamide/acrylic acid/2-acrylamido 2-methylpropane sulfonic acid(AM/AA/AMPS) copolymer(P3A) at 90℃ was studied. The results show that the polymer hydrolysis doesn't obey the monotonic kinetic model and there are two reaction stages, involving inter- and intra-molecular reaction mechanisms, respectively. In the first stage the hydrolysis of AM units occurs predominately and the reaction rate much depends on the pH value for the reaction is controlled by direct attacking of hydroxide ions. Whereas in the latter stage the hydrolysis of AMPS units is the main reaction and the reaction rate is less related to the pH due to the intermolecular catalysis by the adjacent AA units. The effects of composition and chain conformation of copolymers on the hydrolysis reaction also have been discussed.
The hydrolysis of acrylamide/acrylic acid/2-acrylamido 2-methylpropane sulfonic acid(AM/AA/AMPS) copolymer(P3A) at 90℃ was studied. The results show that the polymer hydrolysis doesn't obey the monotonic kinetic model and there are two reaction stages, involving inter- and intra-molecular reaction mechanisms, respectively. In the first stage the hydrolysis of AM units occurs predominately and the reaction rate much depends on the pH value for the reaction is controlled by direct attacking of hydroxide ions. Whereas in the latter stage the hydrolysis of AMPS units is the main reaction and the reaction rate is less related to the pH due to the intermolecular catalysis by the adjacent AA units. The effects of composition and chain conformation of copolymers on the hydrolysis reaction also have been discussed.
2000, 17(2): 121-125
Abstract:
The effect of support on the catalytic performance of Co catalysts supported on V-Al2O3, SiO2 and HZSM-5 Zeolite for CH4/CO2 reforming to syngas was studied by fixed-bed microreactor, XRD and TPR techniques. The results showed that the interaction between metal and support is the main factor affecting catalyst activity and stability. It is found that HZSM-5 is the best support and its Si/Al ratio affected resistance of the catalyst to carbon deposition. In contrast to Co/HZSM-5 catalyst, Co/SiO2 and Co/Al2O3(Co loading <6% (mass fraction)) catalysts showed poor activity and poor stability. They were deactivated by sintering of Co particles and transformation of Co0 to CoAl2O4. The relation between catalytic performance and metal-support interaction was discussed.
The effect of support on the catalytic performance of Co catalysts supported on V-Al2O3, SiO2 and HZSM-5 Zeolite for CH4/CO2 reforming to syngas was studied by fixed-bed microreactor, XRD and TPR techniques. The results showed that the interaction between metal and support is the main factor affecting catalyst activity and stability. It is found that HZSM-5 is the best support and its Si/Al ratio affected resistance of the catalyst to carbon deposition. In contrast to Co/HZSM-5 catalyst, Co/SiO2 and Co/Al2O3(Co loading <6% (mass fraction)) catalysts showed poor activity and poor stability. They were deactivated by sintering of Co particles and transformation of Co0 to CoAl2O4. The relation between catalytic performance and metal-support interaction was discussed.
2000, 17(2): 126-130
Abstract:
Ten dialkyltin complexes (RCO2)2SnR'2[R=Fc,FcCO(CH2)2, 4-Fc-C6H4, 2-Fc-C6H4, FcCH=CH (Fc=ferrocenyl); R'=n-Bu, n-Oct] have been synthesized and characterized by elemental analysis, IR and NMR (1H, 13C) spectroscopy. The results indicated that the Sn atom in these complexes is in a six-coordinated distorted octahedron. The antitumour activity assay results showed that (n-Bu)2Sn(O2CR)2 exhibited a good antitumour activity in vitro against HL-60、HCT-8、BGC-823 and KB tumour cells.
Ten dialkyltin complexes (RCO2)2SnR'2[R=Fc,FcCO(CH2)2, 4-Fc-C6H4, 2-Fc-C6H4, FcCH=CH (Fc=ferrocenyl); R'=n-Bu, n-Oct] have been synthesized and characterized by elemental analysis, IR and NMR (1H, 13C) spectroscopy. The results indicated that the Sn atom in these complexes is in a six-coordinated distorted octahedron. The antitumour activity assay results showed that (n-Bu)2Sn(O2CR)2 exhibited a good antitumour activity in vitro against HL-60、HCT-8、BGC-823 and KB tumour cells.
2000, 17(2): 131-133
Abstract:
Methyl methacrylate is found to be polymerized effectively by diphenylamido-bis-(methylcyclopentadienyl) ytterbium complex (MeCp)2YbNPh2(THF). The reaction can be carried out over a wide range of temperature from -40℃ to 40℃. The polymerization activities of the ytterbocene complexes decrease with the increase of the volume of the ligand in order of MeC5H4> t-BuC5H4> Me5C5.
Methyl methacrylate is found to be polymerized effectively by diphenylamido-bis-(methylcyclopentadienyl) ytterbium complex (MeCp)2YbNPh2(THF). The reaction can be carried out over a wide range of temperature from -40℃ to 40℃. The polymerization activities of the ytterbocene complexes decrease with the increase of the volume of the ligand in order of MeC5H4> t-BuC5H4> Me5C5.
2000, 17(2): 134-137
Abstract:
The charge transfer salts, (NMPH)3PMo12O40·CH3CN(Ⅰ), (NMPH)4SiMo12-O40·CH3CN(Ⅱ) and (NMPH)4GeMo12O40·CH3CN(Ⅲ), having second-order nonlinear optical property were synthesized from N-methylpyrrolidone(NMP) and HnXMo12O40·mH2O(X=P,Si,Ge) via recrystallization in methylcyanide, and characterized by elemental analysis, IR, and reflectance spectroscopy. The results indicate that the anions of the heteropoly acids remain unchanged in charge transfer salt formation. The salts are formed through combination of the Natoms of NMP with the H+ of the acids. Charge transfer between the anions and cations occurs under irradiation of high voltage mercury lamp. The nonlinear optical property measurements indicate the second harmonic generation intensity of the three charge transfer salts:IⅠ2k=0.3IKDP,IⅡ2k=0 and IⅢ2k=0.02IKDP, respectively, and the third order susceptibility of the three charge transfer salts: iⅠ(3)=5.0×10-14 esu,iⅡ(3)=3.1×10-13 esu and iⅢ(3)=4.3×10-13 esu, respectively.
The charge transfer salts, (NMPH)3PMo12O40·CH3CN(Ⅰ), (NMPH)4SiMo12-O40·CH3CN(Ⅱ) and (NMPH)4GeMo12O40·CH3CN(Ⅲ), having second-order nonlinear optical property were synthesized from N-methylpyrrolidone(NMP) and HnXMo12O40·mH2O(X=P,Si,Ge) via recrystallization in methylcyanide, and characterized by elemental analysis, IR, and reflectance spectroscopy. The results indicate that the anions of the heteropoly acids remain unchanged in charge transfer salt formation. The salts are formed through combination of the Natoms of NMP with the H+ of the acids. Charge transfer between the anions and cations occurs under irradiation of high voltage mercury lamp. The nonlinear optical property measurements indicate the second harmonic generation intensity of the three charge transfer salts:IⅠ2k=0.3IKDP,IⅡ2k=0 and IⅢ2k=0.02IKDP, respectively, and the third order susceptibility of the three charge transfer salts: iⅠ(3)=5.0×10-14 esu,iⅡ(3)=3.1×10-13 esu and iⅢ(3)=4.3×10-13 esu, respectively.
2000, 17(2): 138-141
Abstract:
The kinetics and mechanism of redox reaction between hydroxylamine(HAN) and plutonium(Ⅳ) in nitric acid medium have been studied by spectrophotometry. The rate equation of the reaction is found to be -d[Pu(Ⅳ)]/dt=k[Pu(Ⅳ)]2[HAN]2/([Pu(Ⅲ)]2[H+]4) At_=3.00 mol/L and 25℃ the calculated rate constant k is (17.4±0.48) mol 3/(L3·min). A possible mechanism is proposed on the basis of the path of single-electron transfer. The ESR results show that both the opposite reaction and the oxidation reaction are the rate controlling steps: PuOH3++NH2OH⇌Pu3++HNHO+H2O
The kinetics and mechanism of redox reaction between hydroxylamine(HAN) and plutonium(Ⅳ) in nitric acid medium have been studied by spectrophotometry. The rate equation of the reaction is found to be -d[Pu(Ⅳ)]/dt=k[Pu(Ⅳ)]2[HAN]2/([Pu(Ⅲ)]2[H+]4) At_=3.00 mol/L and 25℃ the calculated rate constant k is (17.4±0.48) mol 3/(L3·min). A possible mechanism is proposed on the basis of the path of single-electron transfer. The ESR results show that both the opposite reaction and the oxidation reaction are the rate controlling steps: PuOH3++NH2OH⇌Pu3++HNHO+H2O
2000, 17(2): 142-145
Abstract:
Two tetraazamacrocyclics: 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclote-tradecane (Me6[14]N4) and 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-N-acetic acid(Me6[14]N4CH2COOH) were synthesized and attached covalently to chlormeth-atedyl polystyrene bead both in gel and macropore type, respectively. The four polymer macrocyclic ligands(A,A*,B,B*) thus obtained showed a good coordination ability and their coordination capacities and selectivity properties towards Co(Ⅱ), Ni(Ⅱ), Cu(Ⅱ), and Zn(Ⅱ) were studied. The coordinated metal ion could be easily leached out by dilute hydro-chloric acid from the polymeric macrocyclic ligands and the latter could be used repeatedly.
Two tetraazamacrocyclics: 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclote-tradecane (Me6[14]N4) and 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-N-acetic acid(Me6[14]N4CH2COOH) were synthesized and attached covalently to chlormeth-atedyl polystyrene bead both in gel and macropore type, respectively. The four polymer macrocyclic ligands(A,A*,B,B*) thus obtained showed a good coordination ability and their coordination capacities and selectivity properties towards Co(Ⅱ), Ni(Ⅱ), Cu(Ⅱ), and Zn(Ⅱ) were studied. The coordinated metal ion could be easily leached out by dilute hydro-chloric acid from the polymeric macrocyclic ligands and the latter could be used repeatedly.
2000, 17(2): 146-149
Abstract:
The aggregation behavior of AOT(bis(2-ethylhexyl)-sodium sulfosuccinate) mixed with polymer surfactants GP330(glycerin polyoxypropyl ether) or L61(poly(PEO-b-PPO) in nonpolar solvents and the luminescence behavior of ruthenium tris(2,2'-bipyridine) in the mixed reverse micelles have been studied. The results indicated that CMC of the system increased with increase in mole ratio of the polymer to AOT, but it couldn't be measured by the water solubilization method when the mole ratio increased to 1:1, and that the fluorescence intensity of the probe decreased with increase in water content in the reverse micelles and the emission λmax shifted to longer wavelengths. The results also indicated that increase in content of polymer surfactants could cause the hydration to be completed in lower W0(mole ratio of H2O to surfactant in organic phase) value.
The aggregation behavior of AOT(bis(2-ethylhexyl)-sodium sulfosuccinate) mixed with polymer surfactants GP330(glycerin polyoxypropyl ether) or L61(poly(PEO-b-PPO) in nonpolar solvents and the luminescence behavior of ruthenium tris(2,2'-bipyridine) in the mixed reverse micelles have been studied. The results indicated that CMC of the system increased with increase in mole ratio of the polymer to AOT, but it couldn't be measured by the water solubilization method when the mole ratio increased to 1:1, and that the fluorescence intensity of the probe decreased with increase in water content in the reverse micelles and the emission λmax shifted to longer wavelengths. The results also indicated that increase in content of polymer surfactants could cause the hydration to be completed in lower W0(mole ratio of H2O to surfactant in organic phase) value.
2000, 17(2): 150-153
Abstract:
The extraction-adsorption property of dodecylamine(N12) levextrel resin in weak acid solution towards silver ion and the composition of the extracted species have been studied. The adsorption capacity of the resin for silver ion was 120.3 mg/g. The ratio of N12 to silver in extracted species was near 1:1. The N12 resin could be used repeatedly. The mechanism of the extraction-adsorption has been discussed briefly based on the IR results.
The extraction-adsorption property of dodecylamine(N12) levextrel resin in weak acid solution towards silver ion and the composition of the extracted species have been studied. The adsorption capacity of the resin for silver ion was 120.3 mg/g. The ratio of N12 to silver in extracted species was near 1:1. The N12 resin could be used repeatedly. The mechanism of the extraction-adsorption has been discussed briefly based on the IR results.
2000, 17(2): 154-158
Abstract:
Thirteen trialkyltin(Ⅳ) ferrocene carboxylates were synthesized. Their compositions and structures were characterized by UV, IR, 1H NMR and elemental analysis. The bioassay tests showed that the bioactivity selectivity of the compounds was in close relation with the substituents on the Sn atom. The compounds having cyclohexyl, butyl, methyl and RMeSiCH2(R=Me,Et) on the Sn atom exhibited an excellent acaricidal activity and among them the tributyltin ferrocene carboxylate appeared to be the most fungicidal active.
Thirteen trialkyltin(Ⅳ) ferrocene carboxylates were synthesized. Their compositions and structures were characterized by UV, IR, 1H NMR and elemental analysis. The bioassay tests showed that the bioactivity selectivity of the compounds was in close relation with the substituents on the Sn atom. The compounds having cyclohexyl, butyl, methyl and RMeSiCH2(R=Me,Et) on the Sn atom exhibited an excellent acaricidal activity and among them the tributyltin ferrocene carboxylate appeared to be the most fungicidal active.
2000, 17(2): 159-162
Abstract:
Nano-powders with different mole ratio of Al2O3 to SiO2 have been prepared by hydrolysis-precipitation and coating-precipitation methods. The chemical composition, crystalline state, morphology and infrared emmision property of the powders have been investigated by ICP, XRD and TEM. The results show that V-Al2O3 or Al-Si spinel with antispinel structure and vacancy have higher infrared emmisivity in wavelength range of 8~15 μm at room temperatrue. The thin piece particles with low symmetry structure show higher infrared property than the spherical particles and decease of particle size is in favor of improving the infrared property.
Nano-powders with different mole ratio of Al2O3 to SiO2 have been prepared by hydrolysis-precipitation and coating-precipitation methods. The chemical composition, crystalline state, morphology and infrared emmision property of the powders have been investigated by ICP, XRD and TEM. The results show that V-Al2O3 or Al-Si spinel with antispinel structure and vacancy have higher infrared emmisivity in wavelength range of 8~15 μm at room temperatrue. The thin piece particles with low symmetry structure show higher infrared property than the spherical particles and decease of particle size is in favor of improving the infrared property.
2000, 17(2): 163-164
Abstract:
For hydrogenation of dibenzo-18-crown-6 the catlalyst RuO2 on alumina was used instead of reported Pichler-ruthenium. The separation and purification processes of the target product also have been improved. The method is much simple, economic and time-saving.
For hydrogenation of dibenzo-18-crown-6 the catlalyst RuO2 on alumina was used instead of reported Pichler-ruthenium. The separation and purification processes of the target product also have been improved. The method is much simple, economic and time-saving.
2000, 17(2): 165-167
Abstract:
PEKEKK(T) and PEKEKK(T/I) have two different crystal structures: a conventional Form Ⅰ structure, the same as that observed in PEEK, which is usually developed from melt crystallization, and a new Form Ⅱ structure which can be developed from cold crystallization or solvent induced crystallization(by exposing the glassy state sample to methylene chloride). PEKEKK(I) does not show polymorphism.
PEKEKK(T) and PEKEKK(T/I) have two different crystal structures: a conventional Form Ⅰ structure, the same as that observed in PEEK, which is usually developed from melt crystallization, and a new Form Ⅱ structure which can be developed from cold crystallization or solvent induced crystallization(by exposing the glassy state sample to methylene chloride). PEKEKK(I) does not show polymorphism.
2000, 17(2): 168-170
Abstract:
Inverse microemulsion copolymerizations of acrylamide(AM) with acrylimide ethyltrimethylammonium chloride(AETMAC) have been carried out in the systems of nonionic emulsifier SPAN-80 and anionic emulsifier sodium di(2-ethyl)-hexyl phosphate(DOP), respectively, and the effects of the emulsifiers on the copolymerization rate and reactivity ratio have been investigated. The copolymerization rate was found higher in DOP system and the reactivity ratio of AETMAC was lower in SPAN-80 system than in DOP system and aqueous solution. The results are explained in terms of the difference in tightness of emulsifier layers.
Inverse microemulsion copolymerizations of acrylamide(AM) with acrylimide ethyltrimethylammonium chloride(AETMAC) have been carried out in the systems of nonionic emulsifier SPAN-80 and anionic emulsifier sodium di(2-ethyl)-hexyl phosphate(DOP), respectively, and the effects of the emulsifiers on the copolymerization rate and reactivity ratio have been investigated. The copolymerization rate was found higher in DOP system and the reactivity ratio of AETMAC was lower in SPAN-80 system than in DOP system and aqueous solution. The results are explained in terms of the difference in tightness of emulsifier layers.
2000, 17(2): 171-173
Abstract:
A method for separation of glucose oxidase(GOD) has been developed. A chroma tographic column is filled with an anion exchanger of styrene-divinyl-benzene matrix containing quaternary ammonium salt. The buffered phosphate and acetate solutions were used as eluents. Two GOD components(GOD A and GOD B) were separated by this method. Their enzyme activity and Y potential values were 86.9, 27.3, and -4.3 mV, -6.4 mV, respectively. The simplicity and low cost of the method make it valuable for practical applications.
A method for separation of glucose oxidase(GOD) has been developed. A chroma tographic column is filled with an anion exchanger of styrene-divinyl-benzene matrix containing quaternary ammonium salt. The buffered phosphate and acetate solutions were used as eluents. Two GOD components(GOD A and GOD B) were separated by this method. Their enzyme activity and Y potential values were 86.9, 27.3, and -4.3 mV, -6.4 mV, respectively. The simplicity and low cost of the method make it valuable for practical applications.
2000, 17(2): 174-176
Abstract:
Three axially bromo-substituted subphthalocyanines(SubPc) were synthesized by reacting phthalodinitriles with boron tribromide. They have very good solubility in many common organic solvents. Their electronic absorption spectra and fluorescence emission spectra were measured. These SubPcs have a maximum absorption at 570 nm, which are blue-shifted about 100 nm compared with corresponding phthalocyanine. When U-position substituent is -OCH2C(CH3)3, the SubPc(2b) has fluorescence emission peaks at 415 and 608 nm. However, when there are two substituents at T-position, the SubPc(2c) has only one fluorescence emission peak at 435 nm.
Three axially bromo-substituted subphthalocyanines(SubPc) were synthesized by reacting phthalodinitriles with boron tribromide. They have very good solubility in many common organic solvents. Their electronic absorption spectra and fluorescence emission spectra were measured. These SubPcs have a maximum absorption at 570 nm, which are blue-shifted about 100 nm compared with corresponding phthalocyanine. When U-position substituent is -OCH2C(CH3)3, the SubPc(2b) has fluorescence emission peaks at 415 and 608 nm. However, when there are two substituents at T-position, the SubPc(2c) has only one fluorescence emission peak at 435 nm.
2000, 17(2): 177-179
Abstract:
Poly (ethylene oxide)/montmorillonite nanocopmosite hybrids were prepared by melt intercalation. The X-ray diffraction patterns showed that the layered spacing enlarged from 2.52 nm(for pure montmorillonite) to 3.94 nm for hybrid and the diffraction intensity of crystalline PEO was decreased. The DSC results exhibited a great decrease of the PEO/montmorillonite, implying that PEO molecules are easily intercalated into the layered montmorllonite. Thus, the low crystallinity in composite products is caused by the confinement of PEO molecule motion between the montmorillonite layers. The intercalating mechansim between PEO and montmorillonite has been discussed briefly.
Poly (ethylene oxide)/montmorillonite nanocopmosite hybrids were prepared by melt intercalation. The X-ray diffraction patterns showed that the layered spacing enlarged from 2.52 nm(for pure montmorillonite) to 3.94 nm for hybrid and the diffraction intensity of crystalline PEO was decreased. The DSC results exhibited a great decrease of the PEO/montmorillonite, implying that PEO molecules are easily intercalated into the layered montmorllonite. Thus, the low crystallinity in composite products is caused by the confinement of PEO molecule motion between the montmorillonite layers. The intercalating mechansim between PEO and montmorillonite has been discussed briefly.
2000, 17(2): 180-182
Abstract:
A fullerene-styrene-maleic anhydride ternary copolymer was synthesized. It is soluble in water and of spherical shape with an average diameter of about 83 nm. As an additive for a base stock (a triethanolamine solution of mass fraction 2%), the fullerene copolymer was able to raise load-carrying capacity and reduce the friction coeffient considerably.
A fullerene-styrene-maleic anhydride ternary copolymer was synthesized. It is soluble in water and of spherical shape with an average diameter of about 83 nm. As an additive for a base stock (a triethanolamine solution of mass fraction 2%), the fullerene copolymer was able to raise load-carrying capacity and reduce the friction coeffient considerably.
2000, 17(2): 183-185
Abstract:
Polycrystalline powders of title compound were prepared by solid state reaction at lower temperature. The exitation and emmission spectra of the system were recorded and discussed. The results showed that there occurs an energy transfer from Gd3+ to Eu3+. The luminescence intensity of Eu3+ was found increased with increasing of Gd3+ concentration. However, Sm3+ had a quenching influence on the luminescence of Eu3+.
Polycrystalline powders of title compound were prepared by solid state reaction at lower temperature. The exitation and emmission spectra of the system were recorded and discussed. The results showed that there occurs an energy transfer from Gd3+ to Eu3+. The luminescence intensity of Eu3+ was found increased with increasing of Gd3+ concentration. However, Sm3+ had a quenching influence on the luminescence of Eu3+.
2000, 17(2): 186-188
Abstract:
The octadecylamine was selected as a monolayer-forming material and xylene as a solvent to increase the surface energy of ammonium nitrate. After monolayer self-assembling through hydrogen bonding, Coulomb's force and polarization action on the interface of xylene/ammonium nitrate, the octadecylamine at a concentration of 2×10-4 mol/L in xylene can be considered to be self-assembled on the surface of ammonium nitrate. The moisture absorption of the ammonium nitrate after surface modification has only 58% of that of the pure ammonium nitrate.
The octadecylamine was selected as a monolayer-forming material and xylene as a solvent to increase the surface energy of ammonium nitrate. After monolayer self-assembling through hydrogen bonding, Coulomb's force and polarization action on the interface of xylene/ammonium nitrate, the octadecylamine at a concentration of 2×10-4 mol/L in xylene can be considered to be self-assembled on the surface of ammonium nitrate. The moisture absorption of the ammonium nitrate after surface modification has only 58% of that of the pure ammonium nitrate.
2000, 17(2): 189-191
Abstract:
1,3-specific lipase(PSL)-catalyzed glycerolysis of lard was performed in microemulsions containing sodium bis(2-ethylhexyl) sulfosuccinate(AOT) and a combination of water and glycerol as the polar components. The effects of reaction conditions and system parameters on the yield of monofattyacylglycerols have been investigated and the optimum conditions of syntheses of monofattyacylglycerols were established. The reactions were carried out at 34℃, iso octane being the best hydrocarbon. The other optima were established as follows: pH, 7.0; water content(in mass% of the system), 0.8; AOT content 5%; glycerol content 2.5%, and the monofattyacylglycerols yield herein was 17.3%. Maximum yield of monofattyacylglycerols is obtained at optimum molar ratio of (water+glycerol)/surfactant 6.3, which corresponds to droplet size of ca. 7.2 nm.
1,3-specific lipase(PSL)-catalyzed glycerolysis of lard was performed in microemulsions containing sodium bis(2-ethylhexyl) sulfosuccinate(AOT) and a combination of water and glycerol as the polar components. The effects of reaction conditions and system parameters on the yield of monofattyacylglycerols have been investigated and the optimum conditions of syntheses of monofattyacylglycerols were established. The reactions were carried out at 34℃, iso octane being the best hydrocarbon. The other optima were established as follows: pH, 7.0; water content(in mass% of the system), 0.8; AOT content 5%; glycerol content 2.5%, and the monofattyacylglycerols yield herein was 17.3%. Maximum yield of monofattyacylglycerols is obtained at optimum molar ratio of (water+glycerol)/surfactant 6.3, which corresponds to droplet size of ca. 7.2 nm.
2000, 17(2): 192-194
Abstract:
Title moly bdogadolinium hetero poly com pound ha s been synthesized and used to catalize the hydrox ylation of phenol with hydrogen peroxide. The effects of reaction time, tempera ture, pH value, n(phOH)/n(H2O2) and solvent on the cataly ticactivity for phenol hydrox ylation have been investigated. The results show that the titlecom pound in the presence of V2O5 shows an excellent catalytic activity for phenol hydroxylation. When methanol is used as solvent at n(phOH)/n(H2O2)=1:2, pH=5, at 343 K and for 4 h, hydroquino ne in yield of 42.10% is obtained with phenol conversion of 40.50%.
Title moly bdogadolinium hetero poly com pound ha s been synthesized and used to catalize the hydrox ylation of phenol with hydrogen peroxide. The effects of reaction time, tempera ture, pH value, n(phOH)/n(H2O2) and solvent on the cataly ticactivity for phenol hydrox ylation have been investigated. The results show that the titlecom pound in the presence of V2O5 shows an excellent catalytic activity for phenol hydroxylation. When methanol is used as solvent at n(phOH)/n(H2O2)=1:2, pH=5, at 343 K and for 4 h, hydroquino ne in yield of 42.10% is obtained with phenol conversion of 40.50%.
2000, 17(2): 195-197
Abstract:
Nanoparticles of polystyrene/T-Fe2O3 composites were prepared by method of insertion in sodium dodecylbenzene sulfonate(SDBS) micellar system. The orange T-Fe2O3 particles of about 6 nm were first prepared from 0.25 mol/L FeCl2 and (NH3)2CO3 in 0.1% surfactant solution at pH=4,105℃ for 10 h. The title nanoparticles were prepared then in conditions of SDBS: styrene: H2O(mass fraction)=0.1:1:9, 85℃, 8 h, using ammonium persulfate(APS) as an initiator. The composite nanoparticles sized in 20~50 nm and showed magnetic property.
Nanoparticles of polystyrene/T-Fe2O3 composites were prepared by method of insertion in sodium dodecylbenzene sulfonate(SDBS) micellar system. The orange T-Fe2O3 particles of about 6 nm were first prepared from 0.25 mol/L FeCl2 and (NH3)2CO3 in 0.1% surfactant solution at pH=4,105℃ for 10 h. The title nanoparticles were prepared then in conditions of SDBS: styrene: H2O(mass fraction)=0.1:1:9, 85℃, 8 h, using ammonium persulfate(APS) as an initiator. The composite nanoparticles sized in 20~50 nm and showed magnetic property.
2000, 17(2): 198-200
Abstract:
The extraction mechanism of rare earth elements from chloride medium with sec-octylphenoxy acetic acid(CA-12) in n-heptane has been studied. The results showed that CA-12 could be applied to separation of Y from light rare earth mixture. The structures of the extracted complexes were deduced based on the IR measurements.
The extraction mechanism of rare earth elements from chloride medium with sec-octylphenoxy acetic acid(CA-12) in n-heptane has been studied. The results showed that CA-12 could be applied to separation of Y from light rare earth mixture. The structures of the extracted complexes were deduced based on the IR measurements.
2000, 17(2): 201-202
Abstract:
Rh(Ⅲ) and Ir(Ⅲ) were separated satisfactorily in Tween80-(NH4)2SO4-H2O system by the liquid-solid extraction in form of complexes with stannous chloride.
Rh(Ⅲ) and Ir(Ⅲ) were separated satisfactorily in Tween80-(NH4)2SO4-H2O system by the liquid-solid extraction in form of complexes with stannous chloride.
2000, 17(2): 203-205
Abstract:
The solubilities of YCl3-D,L-U-Phenyl-T-alanine(phe)-H2O ternary system at 25℃ were investigated using a semimicro phase equilibrium method and the refractive indices of the saturated solutions were determined. The results indicated that there are two new complexes formed in this system at 25℃, namely, Y(Phe)Cl3·3H2O and Y(Phe)2Cl3·6H2O, both are incongreunt in water.
The solubilities of YCl3-D,L-U-Phenyl-T-alanine(phe)-H2O ternary system at 25℃ were investigated using a semimicro phase equilibrium method and the refractive indices of the saturated solutions were determined. The results indicated that there are two new complexes formed in this system at 25℃, namely, Y(Phe)Cl3·3H2O and Y(Phe)2Cl3·6H2O, both are incongreunt in water.
2000, 17(2): 206-208
Abstract:
(S)-and (R)-2-hydrox ymethyl py rrolidine(2) were prepared from L-proline and D-glutamic acid, respectively. After acyla tion with propionic anhydride they gave 2-hydro-xymethyl-1-propionyl pyrrolidine(3). A chiral center was introduced into (3) on alkylation with propyl bromide in the presence of lithium diisopropy lamide(LDA) and (4) was formed. The alarm pheromone of leaf-cutting ant, (S) and (R)-4-methy l-3-heptanone (1) were obtained from (4) by acid hydroly sis and reacting with ethy llithium. Both isomers of (1) have optical yield of 85% e. e..
(S)-and (R)-2-hydrox ymethyl py rrolidine(2) were prepared from L-proline and D-glutamic acid, respectively. After acyla tion with propionic anhydride they gave 2-hydro-xymethyl-1-propionyl pyrrolidine(3). A chiral center was introduced into (3) on alkylation with propyl bromide in the presence of lithium diisopropy lamide(LDA) and (4) was formed. The alarm pheromone of leaf-cutting ant, (S) and (R)-4-methy l-3-heptanone (1) were obtained from (4) by acid hydroly sis and reacting with ethy llithium. Both isomers of (1) have optical yield of 85% e. e..
2000, 17(2): 209-211
Abstract:
1-Phenylsulfonyl-2-propanone was reduced to 1-phenylsulfonyl-2-propanol with baker's yeast in very high chemical yield and optical purity, this alcohol was then alkylated, desulfurated and esterified to the target compound S-2-acetoxyltridecane which had very high optical purity.
1-Phenylsulfonyl-2-propanone was reduced to 1-phenylsulfonyl-2-propanol with baker's yeast in very high chemical yield and optical purity, this alcohol was then alkylated, desulfurated and esterified to the target compound S-2-acetoxyltridecane which had very high optical purity.
2000, 17(2): 212-213
Abstract:
Title compound has been synthesized. Its optical and thermal properties are ground state dipole moment 3.036×10-29C·m, λmax=213.9 nm, n25 (532 nm)=1.4190, decomposition temperature 330℃, molecular hyperpolarisability 2.4467×10-29 esu.
Title compound has been synthesized. Its optical and thermal properties are ground state dipole moment 3.036×10-29C·m, λmax=213.9 nm, n25 (532 nm)=1.4190, decomposition temperature 330℃, molecular hyperpolarisability 2.4467×10-29 esu.
2000, 17(2): 214-216
Abstract:
The ring-opening reaction of methyloxirane(PO) in hydrochloric acid(HCl) has been studied by NMR and gas chromatography. It is found that under experimental conditions T and U-chloropropanol in the reaction products were in a molar ratio of about 2:1. The ratio was almost constant when the molar ratio of cPO:cHCl ranged from 1:0.3 to 1:1.4, at reaction temperature from 0 to 65℃ and reaction time from 1 to 60 min. It is proposed that the addition reaction of HCl should follow an SN2 mechanism, and that which carbon atom would be attacked by nucleophilic agent Cl- is decided by space factor and not by the electron factor.
The ring-opening reaction of methyloxirane(PO) in hydrochloric acid(HCl) has been studied by NMR and gas chromatography. It is found that under experimental conditions T and U-chloropropanol in the reaction products were in a molar ratio of about 2:1. The ratio was almost constant when the molar ratio of cPO:cHCl ranged from 1:0.3 to 1:1.4, at reaction temperature from 0 to 65℃ and reaction time from 1 to 60 min. It is proposed that the addition reaction of HCl should follow an SN2 mechanism, and that which carbon atom would be attacked by nucleophilic agent Cl- is decided by space factor and not by the electron factor.
2000, 17(2): 217-218
Abstract:
Deacetylated chitosan solution mixed with inorganic flocculant has a good flocculation and decoloration efficiency towards the waste printing and dyeing water. Some factors influencing the process such as amount of chitosan, deacetylation degree of chitosan, mixing time, setting time have been examined.
Deacetylated chitosan solution mixed with inorganic flocculant has a good flocculation and decoloration efficiency towards the waste printing and dyeing water. Some factors influencing the process such as amount of chitosan, deacetylation degree of chitosan, mixing time, setting time have been examined.
2000, 17(2): 219-221
Abstract:
Hexagonal ferrite samples of LaxBa1-xFe12O19 (x≤0.2) have been prepared by a sol-gel method. The composition ratios of the samples were confirmed by atomic absorption spectrometry and chemical analysis. The results of XRD, DTA, TGA and SEM showed that the samples have the same crystal structure as barium ferrite, with grain sizes being less than 1 μm.
Hexagonal ferrite samples of LaxBa1-xFe12O19 (x≤0.2) have been prepared by a sol-gel method. The composition ratios of the samples were confirmed by atomic absorption spectrometry and chemical analysis. The results of XRD, DTA, TGA and SEM showed that the samples have the same crystal structure as barium ferrite, with grain sizes being less than 1 μm.
2000, 17(2): 222-223
Abstract:
The blocking reaction of polyisocyanates with active hydrogen containing subs tances and the deblocking of the reaction products have been investigated by IR and TGA. The results showed that the initial deblocking temperature of the blocked polyisocyanates were mainly determined by active hydrogen substances. The deblocking temperature of toluene diisocyanate blocked with methylethylketoxime was 110℃ and this temperature could be more or less reduced by using organic tin catalyst at deblocking reaction.
The blocking reaction of polyisocyanates with active hydrogen containing subs tances and the deblocking of the reaction products have been investigated by IR and TGA. The results showed that the initial deblocking temperature of the blocked polyisocyanates were mainly determined by active hydrogen substances. The deblocking temperature of toluene diisocyanate blocked with methylethylketoxime was 110℃ and this temperature could be more or less reduced by using organic tin catalyst at deblocking reaction.
2000, 17(2): 224-226
Abstract:
The S-(+)-sulcatol(1) was prepared in 4 steps. Sodium phenyl sulfinate was reacted with bromoacetone in ethanol to give 1-phenylsulfonyl-2-propanone(2). Alkylation of (2) by 1-chloro-3-methyl-2-butene(3) in the presence of K2CO3 through solid-liquid PTC in DMF at 40~50℃ gave 3-phenylsulfonyl-6-methyl-5-heptene-2-one(4). The sulfone moiety of (4) was removed by Raney Ni reduction under mild conditions and the key intermediate prochiral 6-methyl-5-heptene-2-one(5) was obtained. Sulcatol(1) with optical purity of 94% e.e. was obtained by Baker's yeast mediated reduction of (5).
The S-(+)-sulcatol(1) was prepared in 4 steps. Sodium phenyl sulfinate was reacted with bromoacetone in ethanol to give 1-phenylsulfonyl-2-propanone(2). Alkylation of (2) by 1-chloro-3-methyl-2-butene(3) in the presence of K2CO3 through solid-liquid PTC in DMF at 40~50℃ gave 3-phenylsulfonyl-6-methyl-5-heptene-2-one(4). The sulfone moiety of (4) was removed by Raney Ni reduction under mild conditions and the key intermediate prochiral 6-methyl-5-heptene-2-one(5) was obtained. Sulcatol(1) with optical purity of 94% e.e. was obtained by Baker's yeast mediated reduction of (5).
2000, 17(2): 227-229
Abstract:
Five title compounds were synthesized and characterized by UV-Vis, IR, elemental analysis, 1H NMR and fluorescence spectra. It is found that the fluorescence intensities of the compounds at optimum pH values were 16 to 319 times as much as that of 4-aminoantipyrine. The influences of the substituents of the compounds on the fluorescence intensity have been discussed.
Five title compounds were synthesized and characterized by UV-Vis, IR, elemental analysis, 1H NMR and fluorescence spectra. It is found that the fluorescence intensities of the compounds at optimum pH values were 16 to 319 times as much as that of 4-aminoantipyrine. The influences of the substituents of the compounds on the fluorescence intensity have been discussed.
2000, 17(2): 230-232
Abstract:
The catalytic activity of the industrial catalyst A110-3 after modification with Mn2+ was found to be increased to about 17.4%. The ammonia synthesis was carried out under conditions of 2.1 MPa, 14400 h-1 and 300℃. The increase in activity is explained in terms of the weakness of Fe-N-N or Fe-N bond based on the XPS and TPD-MS results.
The catalytic activity of the industrial catalyst A110-3 after modification with Mn2+ was found to be increased to about 17.4%. The ammonia synthesis was carried out under conditions of 2.1 MPa, 14400 h-1 and 300℃. The increase in activity is explained in terms of the weakness of Fe-N-N or Fe-N bond based on the XPS and TPD-MS results.
