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2003 Volume 20 Issue 2
2003, 20(2): 103-107
Abstract:
A simple and reliable electroanalytical method is described for the fast determination of aluminum species(total AlT, acid soluble Alr, monomeric Ala, inorganic monomeric Ali, organic monomeric Alo) in natural waters by an a.c. oscillopolarography using quercetin(Qu) and 8-hydroxyquinoline-5-sulfonic acid (8-HQS) as complexing adsorbents. In alkaline buffer solution (pH=8.0), 8-HQS was used to determine the total monomeric aluminum, and in acidified buffer solution (pH=5.0), Qu was used to detect the inorganic monomeric aluminum, respectively. This method has been successfully applied in the analysis of Al species in over 10 natural water samples. The results were in good agreement with those obtained by Driscoll's method. SPE program was used to elaborate on the theoretical foundation of the proposed method.
A simple and reliable electroanalytical method is described for the fast determination of aluminum species(total AlT, acid soluble Alr, monomeric Ala, inorganic monomeric Ali, organic monomeric Alo) in natural waters by an a.c. oscillopolarography using quercetin(Qu) and 8-hydroxyquinoline-5-sulfonic acid (8-HQS) as complexing adsorbents. In alkaline buffer solution (pH=8.0), 8-HQS was used to determine the total monomeric aluminum, and in acidified buffer solution (pH=5.0), Qu was used to detect the inorganic monomeric aluminum, respectively. This method has been successfully applied in the analysis of Al species in over 10 natural water samples. The results were in good agreement with those obtained by Driscoll's method. SPE program was used to elaborate on the theoretical foundation of the proposed method.
2003, 20(2): 108-111
Abstract:
The formation constants of β-cyclodextrin(β-CD) inclusion complex with methyl orange were determined by fluorescence spectroscopy and the TiO2 photocatalytic decolorization of the complex was studied by UV-vis spectral analysis. The results showed that the inclusion complex of β-CD with methyl orange in the mole ratio of 1:1(n(β-CD):n(methyl orange)) and 2:1 depended on the β-CD concentration with formation constants K1:1=7.75×105 L/mol and K1:2=1.86×104 L2/mol2 respectively. The photocatalytic decolorization rate of methyl orange solutions was found to increase with addition of β-CD. The reaction rate increased at pH values of 2.0~4.5 and then decreased on increasing pH values to 12.0. The reaction rate droped with increasing oxygen concentration of the solution.
The formation constants of β-cyclodextrin(β-CD) inclusion complex with methyl orange were determined by fluorescence spectroscopy and the TiO2 photocatalytic decolorization of the complex was studied by UV-vis spectral analysis. The results showed that the inclusion complex of β-CD with methyl orange in the mole ratio of 1:1(n(β-CD):n(methyl orange)) and 2:1 depended on the β-CD concentration with formation constants K1:1=7.75×105 L/mol and K1:2=1.86×104 L2/mol2 respectively. The photocatalytic decolorization rate of methyl orange solutions was found to increase with addition of β-CD. The reaction rate increased at pH values of 2.0~4.5 and then decreased on increasing pH values to 12.0. The reaction rate droped with increasing oxygen concentration of the solution.
2003, 20(2): 112-116
Abstract:
Sodium alginate/IPDI(A-Na/IPDI) microspheres are prepared by exchanging calcium alginate (A-Ca)/IPDI gel microspheres, prepared by crosslinking of calcium alginate with isophorone diisocyanate(IPDI), with sodium citrate. When used for adsorbtion of Pb2+, the highest adsorption percentage of A-Na/IPDI gel microspheres is 99.57%. The limiting adsorption concentration is 0.434 μmol/L and the mass exchange capacity is 383 mg/g. Ion exchange velocity of A-Na/IPDI gel microspheres is much greater than that of chelating resin D418 and polyacrylate resin D113. A-Na/IPDI gel microspheres have rapid adsorption velocity and high selectivity for Pb2+, showing a promising application in adsorption of heavy metal ions in human blood.
Sodium alginate/IPDI(A-Na/IPDI) microspheres are prepared by exchanging calcium alginate (A-Ca)/IPDI gel microspheres, prepared by crosslinking of calcium alginate with isophorone diisocyanate(IPDI), with sodium citrate. When used for adsorbtion of Pb2+, the highest adsorption percentage of A-Na/IPDI gel microspheres is 99.57%. The limiting adsorption concentration is 0.434 μmol/L and the mass exchange capacity is 383 mg/g. Ion exchange velocity of A-Na/IPDI gel microspheres is much greater than that of chelating resin D418 and polyacrylate resin D113. A-Na/IPDI gel microspheres have rapid adsorption velocity and high selectivity for Pb2+, showing a promising application in adsorption of heavy metal ions in human blood.
2003, 20(2): 117-120
Abstract:
Mg-Al layered double hydroxides(LDH) have been synthesized from Mg(NO3)2·6H2O, Al(NO3)3·9H2O, NaOH and Na2CO3 in a rotating liquid-film reactor. It is found that the aging temperature, degree of supersaturation in the course of aging and degree of supersaturation in the course of nucleation are the important factors affecting the crystal structures and crystallite sizes of hydrotalcites. Lower aging temperatures and addition of water during the aging process favour the formation of nano-sized hydrotalcites. When the concentration of Mg2+ is between 0.1~1.6 mol/L the particle size of LDH increases with increase of the Mg2+ concentration.
Mg-Al layered double hydroxides(LDH) have been synthesized from Mg(NO3)2·6H2O, Al(NO3)3·9H2O, NaOH and Na2CO3 in a rotating liquid-film reactor. It is found that the aging temperature, degree of supersaturation in the course of aging and degree of supersaturation in the course of nucleation are the important factors affecting the crystal structures and crystallite sizes of hydrotalcites. Lower aging temperatures and addition of water during the aging process favour the formation of nano-sized hydrotalcites. When the concentration of Mg2+ is between 0.1~1.6 mol/L the particle size of LDH increases with increase of the Mg2+ concentration.
2003, 20(2): 121-124
Abstract:
Berberrabine(BRB) and tetrahydroberberine(THB) were determined simultaneously by combined capillary electrophoresis/conductivity measurements. The effects of pH value and concentration of the running buffer on the determinations were studied. Berberrabine and tetrahydroberberine could be completely separated in a solution of 25 mmol/L Tris with 25 mmol/L citric acid(pH=4.0) within 10 min. An excellent linearity was found between peak area and concentration of analytes in the concentration range of 1.0×10-5~2.5×10-3 mol/L for berberrabine and 8.0×10-6~1.0×10-3 mol/L for tetrahydroberberine, respectively, r>0.998 for all analytes. The average recovery was 96.8% and 99.2% for berberrabine and tetrahydrober-berine, respectively. Satisfactory results were obtained in analysis of practical berberrabine and tetrahydroberberine samples.
Berberrabine(BRB) and tetrahydroberberine(THB) were determined simultaneously by combined capillary electrophoresis/conductivity measurements. The effects of pH value and concentration of the running buffer on the determinations were studied. Berberrabine and tetrahydroberberine could be completely separated in a solution of 25 mmol/L Tris with 25 mmol/L citric acid(pH=4.0) within 10 min. An excellent linearity was found between peak area and concentration of analytes in the concentration range of 1.0×10-5~2.5×10-3 mol/L for berberrabine and 8.0×10-6~1.0×10-3 mol/L for tetrahydroberberine, respectively, r>0.998 for all analytes. The average recovery was 96.8% and 99.2% for berberrabine and tetrahydrober-berine, respectively. Satisfactory results were obtained in analysis of practical berberrabine and tetrahydroberberine samples.
2003, 20(2): 125-129
Abstract:
Two novel polymeric pseudo-crown ethers were synthesized by three simple reactions. Their adsorption properties for metal ions were studied. The results showed that at 25℃ the polymers exhibited adsorption capacities for Ag+,Hg2+ and Pb2+ respectively of 1.006,0.919 and 0.658 mmol/g, when the ion concentration was 0.043 0,0.040 1 and 0.041 6 mol/L, respectively. There occurred an obvious oxidation-reduction course of adsorption of Ag+. The structures of the polymers and its complex with Ag+ were studied by FTIR spectra. The adsorption appeared to be a result of chelated chain formation between oxygen of crown ether and benzylalcohol with metal ions.
Two novel polymeric pseudo-crown ethers were synthesized by three simple reactions. Their adsorption properties for metal ions were studied. The results showed that at 25℃ the polymers exhibited adsorption capacities for Ag+,Hg2+ and Pb2+ respectively of 1.006,0.919 and 0.658 mmol/g, when the ion concentration was 0.043 0,0.040 1 and 0.041 6 mol/L, respectively. There occurred an obvious oxidation-reduction course of adsorption of Ag+. The structures of the polymers and its complex with Ag+ were studied by FTIR spectra. The adsorption appeared to be a result of chelated chain formation between oxygen of crown ether and benzylalcohol with metal ions.
2003, 20(2): 130-133
Abstract:
A series of 4-aryloxyacetamido(propionamido) benzenesulfonamides were synthesized by condensation reaction of aryloxyacetic(propionic) acids with 4-aminobenzenesulfonamides. The products were characterized by 1H NMR, IR, elemental analyses and MS. Most of the compounds have good herbicidal activities.
A series of 4-aryloxyacetamido(propionamido) benzenesulfonamides were synthesized by condensation reaction of aryloxyacetic(propionic) acids with 4-aminobenzenesulfonamides. The products were characterized by 1H NMR, IR, elemental analyses and MS. Most of the compounds have good herbicidal activities.
2003, 20(2): 134-137
Abstract:
The ferroelectric materials, (1-x)Pb(Ni1/3Nb2/3)O3-xPbTiO3[(1-x)PNN-xPT,x(PT)=0,0.15,0.25,0.36,0.45] were prepared from nickel nitrate instead of commonly used nickel oxide. The (1-x)PNN-xPT powders were prepared from the precursor, which was synthesized by adding an aqueous Ni(NO3)2 solution to the alcoholic slurry of PbO, Nb2O5 and TiO2, followed by calcination at 850℃ for 3 h. Without the addition of excess NiO, the (1-x)PNN-xPT ceramics sintered at 1 100℃ for 2 h were dense and composed of only the perovskite phase. The ceramics exhibited better dielectric property than those obtained by Columbite precursor method.
The ferroelectric materials, (1-x)Pb(Ni1/3Nb2/3)O3-xPbTiO3[(1-x)PNN-xPT,x(PT)=0,0.15,0.25,0.36,0.45] were prepared from nickel nitrate instead of commonly used nickel oxide. The (1-x)PNN-xPT powders were prepared from the precursor, which was synthesized by adding an aqueous Ni(NO3)2 solution to the alcoholic slurry of PbO, Nb2O5 and TiO2, followed by calcination at 850℃ for 3 h. Without the addition of excess NiO, the (1-x)PNN-xPT ceramics sintered at 1 100℃ for 2 h were dense and composed of only the perovskite phase. The ceramics exhibited better dielectric property than those obtained by Columbite precursor method.
2003, 20(2): 138-143
Abstract:
Two title complexes [ZnL2]·H2O(1, C16H20N6O5Zn) and VO2L(2, C8H8N3O4V; HL=N-acetylpicoloylhydrazide) have been synthesized. Their crystal data were determined for complex 1 space group C c, a=3.083 2(1) nm, b=0.759 31(3) nm, c=1.837 07(8) nm, β=116.918(2)°, V=3.834 8(3) nm3, Z=8, F(000)=1 824, μ=1.32 mm-1, R=0.034 0, for 3 177 observed reflections(I≥2σ(I)); for complex 2 space group C2/c, a=1.012 2(3) nm, b=1.244 5(4) nm, c=1.694 1(5) nm, β=105.587(7)°, V=2.056(1) nm3, Z=8, F(000)=1 056, μ=0.967 mm-1, R=0.057 7 for 1 268 observed reflections(I≥2σ(I)). The Zinc(Ⅱ) ion in complex 1 is coordinated with two pyridine nitrogen atoms, two diazine nitrogen atoms and two carbonyl oxygen atoms from two tridentate ligands, forming a distorted octahedral of N4O2. The vanadium atom in complex 2 is bound to two terminal oxygen atoms and one tridentate donor ligand in a distorted square pyramidal arrangement. There is an one-dimensional chain structure through the intermolecular hydrogen bonds and intramolecular hydrogen bonds in complex 1. Every two molecules in the crystal of complex 2 are linked by pairs through the intermolecular hydrogen bonds. The second harmonic generation I2ω of complex 1 is 0.85 time as that of KDP.
Two title complexes [ZnL2]·H2O(1, C16H20N6O5Zn) and VO2L(2, C8H8N3O4V; HL=N-acetylpicoloylhydrazide) have been synthesized. Their crystal data were determined for complex 1 space group C c, a=3.083 2(1) nm, b=0.759 31(3) nm, c=1.837 07(8) nm, β=116.918(2)°, V=3.834 8(3) nm3, Z=8, F(000)=1 824, μ=1.32 mm-1, R=0.034 0, for 3 177 observed reflections(I≥2σ(I)); for complex 2 space group C2/c, a=1.012 2(3) nm, b=1.244 5(4) nm, c=1.694 1(5) nm, β=105.587(7)°, V=2.056(1) nm3, Z=8, F(000)=1 056, μ=0.967 mm-1, R=0.057 7 for 1 268 observed reflections(I≥2σ(I)). The Zinc(Ⅱ) ion in complex 1 is coordinated with two pyridine nitrogen atoms, two diazine nitrogen atoms and two carbonyl oxygen atoms from two tridentate ligands, forming a distorted octahedral of N4O2. The vanadium atom in complex 2 is bound to two terminal oxygen atoms and one tridentate donor ligand in a distorted square pyramidal arrangement. There is an one-dimensional chain structure through the intermolecular hydrogen bonds and intramolecular hydrogen bonds in complex 1. Every two molecules in the crystal of complex 2 are linked by pairs through the intermolecular hydrogen bonds. The second harmonic generation I2ω of complex 1 is 0.85 time as that of KDP.
2003, 20(2): 144-148
Abstract:
Condesation of 2-hydroxy-3-tert-butyl-5-methylbezaldehyde with (S,S)-1,2-diphenyl diaminoethane afforded the chiral salen 12, which gave the cobalt complex 13 on reacting with Co(OAc)2·4H2O. The complex 13 was then oxidized to give the chiral catalyst (S,S)-2. Several racemic epoxides were resolved by enantioselective hydrolysis in the presence of (S,S)-2 catalyst, giving optical active epoxides and diols with the e.e. up to 61.6%. Effects of the catalyst structure on its activity and selectivity were discussed based on the optimized conformation of the catalyst obtained using the method of molecular mechanics.
Condesation of 2-hydroxy-3-tert-butyl-5-methylbezaldehyde with (S,S)-1,2-diphenyl diaminoethane afforded the chiral salen 12, which gave the cobalt complex 13 on reacting with Co(OAc)2·4H2O. The complex 13 was then oxidized to give the chiral catalyst (S,S)-2. Several racemic epoxides were resolved by enantioselective hydrolysis in the presence of (S,S)-2 catalyst, giving optical active epoxides and diols with the e.e. up to 61.6%. Effects of the catalyst structure on its activity and selectivity were discussed based on the optimized conformation of the catalyst obtained using the method of molecular mechanics.
2003, 20(2): 149-154
Abstract:
The thermodynamic property of HCl-C3H8O3-NaCl-H2O system has been studied by emf measurement in the cells without liquid junction at 5 to 45℃:Pt,H2(105 Pa)|HCl(c),C3H8O3(w),H2O(1-w)|AgCl-Ag (A) Pt,H2(105 Pa)|HCl(cA),NaCl(cB),C3H8O3(w),H2O(1-w)|AgCl-Ag (B) with the mass fraction of glycerol ω(C3H8O3)=5%, 15% and 20% at a total ionic strength I=1.00 mol/kg. The standard electrode potential of Ag-AgCl in the mixed solvent was determined for cell(A). The activity coefficient γA of HCl in the mixed solvent system was determined from cell(B). The results show that the acti-vity coefficient of HCl in HCl-NaCl solutions still obeys Harned's rule and lg γA is linear to the reciprocal of the absolute temperature at constant composition of the mixture. Relative molar enthalpies LA of HCl are in linear function with the ionic strength fraction of NaCl at constant total ionic strength and temperature. The standard transfer Gibbs free energies of HCl from water to mixed sovents were calculated. The primary, secondary and total medium effect of HCl were calculated and discussed.
The thermodynamic property of HCl-C3H8O3-NaCl-H2O system has been studied by emf measurement in the cells without liquid junction at 5 to 45℃:Pt,H2(105 Pa)|HCl(c),C3H8O3(w),H2O(1-w)|AgCl-Ag (A) Pt,H2(105 Pa)|HCl(cA),NaCl(cB),C3H8O3(w),H2O(1-w)|AgCl-Ag (B) with the mass fraction of glycerol ω(C3H8O3)=5%, 15% and 20% at a total ionic strength I=1.00 mol/kg. The standard electrode potential of Ag-AgCl in the mixed solvent was determined for cell(A). The activity coefficient γA of HCl in the mixed solvent system was determined from cell(B). The results show that the acti-vity coefficient of HCl in HCl-NaCl solutions still obeys Harned's rule and lg γA is linear to the reciprocal of the absolute temperature at constant composition of the mixture. Relative molar enthalpies LA of HCl are in linear function with the ionic strength fraction of NaCl at constant total ionic strength and temperature. The standard transfer Gibbs free energies of HCl from water to mixed sovents were calculated. The primary, secondary and total medium effect of HCl were calculated and discussed.
2003, 20(2): 155-158
Abstract:
Møssbauer spectra of Zr- and Ca-containing fused iron catalysts for ammonia synthesis have been investigated. The results show that the presence of Zr(Ⅳ) in the octahedral B sites of Fe3O4 results in the expansion of B sites, facilitating the reduction of the catalyst and uniform distribution of Al(Ⅲ). For the catalysts containing both Zr4+ and Ca2+ ions the number of Zr4+ entering Fe3O4 lattice decreases due to the interaction between zirconium and calcium, and the Fe2+ ions are reduced more easily at A site of the catalysts. Such a phenomenon occurs more clearly for spherical catalysts obtained from rapid cooling by water.
Møssbauer spectra of Zr- and Ca-containing fused iron catalysts for ammonia synthesis have been investigated. The results show that the presence of Zr(Ⅳ) in the octahedral B sites of Fe3O4 results in the expansion of B sites, facilitating the reduction of the catalyst and uniform distribution of Al(Ⅲ). For the catalysts containing both Zr4+ and Ca2+ ions the number of Zr4+ entering Fe3O4 lattice decreases due to the interaction between zirconium and calcium, and the Fe2+ ions are reduced more easily at A site of the catalysts. Such a phenomenon occurs more clearly for spherical catalysts obtained from rapid cooling by water.
2003, 20(2): 159-162
Abstract:
Ce0.6Zr0.4O2 solid solution was prepared by coprecipitation technique and characterized by XRD and specific surface area measurements. Ce0.6Zr0.4O2 was used to prepare palladium-only three-way catalyst(TWC) and its influence on the performance of TWC was investigated. The results show Ce0.6Zr0.4O2 has a cubic structure similar to CeO2, but its specific surface area decreased slowly as the calcination temperature increased. Being aged at high temperature Ce0.6Zr0.4O2 still showed higher conversion of HC, CO and NO and lower lightening temperature in comparison with CeO2 TWC.
Ce0.6Zr0.4O2 solid solution was prepared by coprecipitation technique and characterized by XRD and specific surface area measurements. Ce0.6Zr0.4O2 was used to prepare palladium-only three-way catalyst(TWC) and its influence on the performance of TWC was investigated. The results show Ce0.6Zr0.4O2 has a cubic structure similar to CeO2, but its specific surface area decreased slowly as the calcination temperature increased. Being aged at high temperature Ce0.6Zr0.4O2 still showed higher conversion of HC, CO and NO and lower lightening temperature in comparison with CeO2 TWC.
2003, 20(2): 163-166
Abstract:
Catalytic synthesis of diethyl carbonate(DEC) by oxidative carbonylation of ethanol in homogeneous CuCl/Schiff-base system has been studied as functions of N-donor ligand, reaction time, temperature, water content and ratio of N-methyl imidazole(NMI) to 1,10-phenanthroline(phen). Catalytic system with CuCl/phen/NMI was found to have a favorable activity in the oxidative carbonylation. Under conditions of 120℃, 2.4 MPa(CO+O2), concentration of CuCl 0.20 mol/L, n(NMI):n(CuCl)=1.25:1, n(NMI): n(phen)=1:1, in 3 hours, conversion of ethanol reached 13.6%, 3 times as much as that of plain CuCl system, with selectivity of DEC being over 99.0%. The catalytic activity of the catalytic system studied could be used repeatedly 4 times without significant loss of activity in the oxidative carbonylation.
Catalytic synthesis of diethyl carbonate(DEC) by oxidative carbonylation of ethanol in homogeneous CuCl/Schiff-base system has been studied as functions of N-donor ligand, reaction time, temperature, water content and ratio of N-methyl imidazole(NMI) to 1,10-phenanthroline(phen). Catalytic system with CuCl/phen/NMI was found to have a favorable activity in the oxidative carbonylation. Under conditions of 120℃, 2.4 MPa(CO+O2), concentration of CuCl 0.20 mol/L, n(NMI):n(CuCl)=1.25:1, n(NMI): n(phen)=1:1, in 3 hours, conversion of ethanol reached 13.6%, 3 times as much as that of plain CuCl system, with selectivity of DEC being over 99.0%. The catalytic activity of the catalytic system studied could be used repeatedly 4 times without significant loss of activity in the oxidative carbonylation.
2003, 20(2): 167-170
Abstract:
A strong cation exchanger, cellulose sodium sulfate(CS) was prepared by reaction of crosslinked rice husk cellulose with H2SO4. Reacting epichlorohydrin crosslinked cellulose with isopentanol and sulfuric acid (in volume ratio 1:1) at 0℃ for 3 h, ion exchangers with exchange capacity of 2.8~3.2 mmol/g were obtained. The exchanger with exchange capacity of 3.0 mmol/g showed an absorptive capacity of 84 mg/g、180 mg/g and 394 mg/g for Cu2+、Ag+、Pb2+ respectively.
A strong cation exchanger, cellulose sodium sulfate(CS) was prepared by reaction of crosslinked rice husk cellulose with H2SO4. Reacting epichlorohydrin crosslinked cellulose with isopentanol and sulfuric acid (in volume ratio 1:1) at 0℃ for 3 h, ion exchangers with exchange capacity of 2.8~3.2 mmol/g were obtained. The exchanger with exchange capacity of 3.0 mmol/g showed an absorptive capacity of 84 mg/g、180 mg/g and 394 mg/g for Cu2+、Ag+、Pb2+ respectively.
2003, 20(2): 171-174
Abstract:
The flotation separation of Pb(Ⅱ) from other metal ions by a system containing sodium nitrate, ammonium thiocyanate, cetyltrimethyl ammonium chloride(CTMAC) and water has been studied. The results showed that in the system consisted of 1.0 g NaNO3, 0.5 mL NH4SCN(0.1 mol/L) and 1.0 mL CTMAC(0.01 mol/L) at pH=6.0, Pb2+ could be floated and separated from the Zn2+, Cu2+, Cd2+, Mn2+, Fe2+, Co2+, Ni2+ and Al3+ mixture in solution.
The flotation separation of Pb(Ⅱ) from other metal ions by a system containing sodium nitrate, ammonium thiocyanate, cetyltrimethyl ammonium chloride(CTMAC) and water has been studied. The results showed that in the system consisted of 1.0 g NaNO3, 0.5 mL NH4SCN(0.1 mol/L) and 1.0 mL CTMAC(0.01 mol/L) at pH=6.0, Pb2+ could be floated and separated from the Zn2+, Cu2+, Cd2+, Mn2+, Fe2+, Co2+, Ni2+ and Al3+ mixture in solution.
2003, 20(2): 175-177
Abstract:
The isothermal mutual solubility and phase relation of MgSO4-Li2SO4-C2H5OH-H2O system at 25℃ have been investigated by using a homemade micro-equilibrium and sampling apparatus. The demixing phenomenon of the system's at below room temperature was observed. The precise demixing composition and composition of double-saturated point of the system have been determined. A unique effect, namely additive property between MgSO4 and Li2SO4 has been observed and explained in terms of "pseudo-ternary system" concept. An empirical formula has been worked out to correlate the mutual solubility.
The isothermal mutual solubility and phase relation of MgSO4-Li2SO4-C2H5OH-H2O system at 25℃ have been investigated by using a homemade micro-equilibrium and sampling apparatus. The demixing phenomenon of the system's at below room temperature was observed. The precise demixing composition and composition of double-saturated point of the system have been determined. A unique effect, namely additive property between MgSO4 and Li2SO4 has been observed and explained in terms of "pseudo-ternary system" concept. An empirical formula has been worked out to correlate the mutual solubility.
2003, 20(2): 178-180
Abstract:
Trans-4-(Dimethylamino)-4'-(diethylamino) stilbene(DMAEAS) has been synthesized and characterized by 1H NMR, IR and elemental analysis. The UV spectrum of the compound has been recorded. The single photon fluorescence spectrum of the compound under 370 nm excitation shows the presence of two bands at 420 nm and 438 nm, respectively.
Trans-4-(Dimethylamino)-4'-(diethylamino) stilbene(DMAEAS) has been synthesized and characterized by 1H NMR, IR and elemental analysis. The UV spectrum of the compound has been recorded. The single photon fluorescence spectrum of the compound under 370 nm excitation shows the presence of two bands at 420 nm and 438 nm, respectively.
2003, 20(2): 181-182
Abstract:
A method of direct synthesis of a novel lamellar vanadium phosphate intercalated with cupric acetylacetonate (Cu(acac)2-LVPO) is reported. The compound was characterized by XRD, IR, EA and TGA techniques.
A method of direct synthesis of a novel lamellar vanadium phosphate intercalated with cupric acetylacetonate (Cu(acac)2-LVPO) is reported. The compound was characterized by XRD, IR, EA and TGA techniques.
2003, 20(2): 183-185
Abstract:
The electrochemical behavior of Mn (Ⅲ)/Mn(Ⅱ)ion-pair on platinum electrode in acid media were studied by cyclic voltammetry.It was demonstrated that the redox process of Mn(Ⅲ)/Mn(Ⅱ) pair was a simple pseudo-reversible one-electron reaction between Mn(Ⅲ) and Mn(Ⅱ).The electrochemical kinetics of the redox reaction on static Pt electrode was a mass transfer controlled one.The calculated diffusion coefficient of Mn(Ⅱ) was 1.48×10-6 cm2/s.
The electrochemical behavior of Mn (Ⅲ)/Mn(Ⅱ)ion-pair on platinum electrode in acid media were studied by cyclic voltammetry.It was demonstrated that the redox process of Mn(Ⅲ)/Mn(Ⅱ) pair was a simple pseudo-reversible one-electron reaction between Mn(Ⅲ) and Mn(Ⅱ).The electrochemical kinetics of the redox reaction on static Pt electrode was a mass transfer controlled one.The calculated diffusion coefficient of Mn(Ⅱ) was 1.48×10-6 cm2/s.
2003, 20(2): 186-188
Abstract:
Cyclic voltammetric behavior of electrooxidation of Mn(Ⅱ) under ultrasound and without ultrasound were compared. With the ultrasound irradiation the reduction peak potential of Pb(Ⅳ)/ Pb(Ⅱ) was found shifted negatively about 0.14 V, initial electrolytic potential reduced 0.2 V and reduction peak current increased. At the same conditions,the conversion of Mn(Ⅱ) was increased. The optimum conditions for electrooxidation were 0.3 mol/L solution of Mn(Ⅱ), 6 mol/L H2SO4, electrolysis potential 2.3 V and 44 W ultrasound.
Cyclic voltammetric behavior of electrooxidation of Mn(Ⅱ) under ultrasound and without ultrasound were compared. With the ultrasound irradiation the reduction peak potential of Pb(Ⅳ)/ Pb(Ⅱ) was found shifted negatively about 0.14 V, initial electrolytic potential reduced 0.2 V and reduction peak current increased. At the same conditions,the conversion of Mn(Ⅱ) was increased. The optimum conditions for electrooxidation were 0.3 mol/L solution of Mn(Ⅱ), 6 mol/L H2SO4, electrolysis potential 2.3 V and 44 W ultrasound.
2003, 20(2): 189-191
Abstract:
A new kind of carbazole-based photorefractive polymer was prepared via a post-azo-coupling reaction. The structure of the polymer was characterized by IR, 1H NMR, UV-vis and GPC. The IR and UV-vis spectra demonstrated that azo group was grafted to the polymer in content of 15.56%. The molecular weight of the polymer as determined by GPC was higher than that of the polymer obtained by common method
A new kind of carbazole-based photorefractive polymer was prepared via a post-azo-coupling reaction. The structure of the polymer was characterized by IR, 1H NMR, UV-vis and GPC. The IR and UV-vis spectra demonstrated that azo group was grafted to the polymer in content of 15.56%. The molecular weight of the polymer as determined by GPC was higher than that of the polymer obtained by common method
2003, 20(2): 192-194
Abstract:
An O-Vanillin-methionine Schiff Base complex with copper(Ⅱ) has been synthesized under a mild condition. The complex has been characterized by elemental analysis, UV, FT-IR, TG-DTA and XRD. The crystal structure of the complex belongs to monoclinic, with space group C2/C, a=2.070 4(12) nm, b=1.431 9(8) nm, c=2.812 9(11) nm, β=133.15(2)°, V=6.084(5) nm3, Z=8, Dc=0.998 Mg/m3, F(000)=1 836, final R=0.121 8. The results revealed it is a tetranuclear copper(Ⅱ) complex.
An O-Vanillin-methionine Schiff Base complex with copper(Ⅱ) has been synthesized under a mild condition. The complex has been characterized by elemental analysis, UV, FT-IR, TG-DTA and XRD. The crystal structure of the complex belongs to monoclinic, with space group C2/C, a=2.070 4(12) nm, b=1.431 9(8) nm, c=2.812 9(11) nm, β=133.15(2)°, V=6.084(5) nm3, Z=8, Dc=0.998 Mg/m3, F(000)=1 836, final R=0.121 8. The results revealed it is a tetranuclear copper(Ⅱ) complex.
2003, 20(2): 195-197
Abstract:
Acetyl-5-bromo-6-methoxynaphthalene(1) was hydrogenated over Pd/C by bubbling H2 into a mixture of n-BuOH, KOH(aq) and CTAB. The effects of the concentration of KOH and n(1): n(Pd): n(CTAB) on the hydrogenation were investigated. Bubbling H2 for 4.25 h at 60℃ into the mentioned mixture solution gave 6-methoxy-2-naphthylethanol in yield of 95.7%.
Acetyl-5-bromo-6-methoxynaphthalene(1) was hydrogenated over Pd/C by bubbling H2 into a mixture of n-BuOH, KOH(aq) and CTAB. The effects of the concentration of KOH and n(1): n(Pd): n(CTAB) on the hydrogenation were investigated. Bubbling H2 for 4.25 h at 60℃ into the mentioned mixture solution gave 6-methoxy-2-naphthylethanol in yield of 95.7%.
2003, 20(2): 198-200
Abstract:
The easily accesible azidoethylacetate 1 was reacted with ferrocene formaldehyde to give azide 2, which was allowed to take Staudinger reactions with triphenylphosphine to give iminophosphorane 3. The imidazolinone derivatives containing ferrocenyl moity(5a~5e) were synthesized by a tandem aza-Wittig reaction of 3 with phenyl isocynate and substituted phenols in yields of 57%~69%. The structures of title compounds were confirmed by elemental analysis,IR and 1H NMR. Two of them 5b and 5c exhibited fungicidal activities and none of them has herbicidal activity and insecticidal activity.
The easily accesible azidoethylacetate 1 was reacted with ferrocene formaldehyde to give azide 2, which was allowed to take Staudinger reactions with triphenylphosphine to give iminophosphorane 3. The imidazolinone derivatives containing ferrocenyl moity(5a~5e) were synthesized by a tandem aza-Wittig reaction of 3 with phenyl isocynate and substituted phenols in yields of 57%~69%. The structures of title compounds were confirmed by elemental analysis,IR and 1H NMR. Two of them 5b and 5c exhibited fungicidal activities and none of them has herbicidal activity and insecticidal activity.
2003, 20(2): 201-202
Abstract:
The synthesis of tri(β-chloroethyl)phosphate(TCEP) from ethylene oxide and phosphorus oxychloride catalyzed by a solid super acid TiSiW12O40/TiO2 has been studied. The optimun reactions conditions are:molar ratio of ethylene oxide to phosphorous oxychloride=3.10:1.00, catalyst amount 1.5%, 5 h and 30~45℃.
The synthesis of tri(β-chloroethyl)phosphate(TCEP) from ethylene oxide and phosphorus oxychloride catalyzed by a solid super acid TiSiW12O40/TiO2 has been studied. The optimun reactions conditions are:molar ratio of ethylene oxide to phosphorous oxychloride=3.10:1.00, catalyst amount 1.5%, 5 h and 30~45℃.
2003, 20(2): 203-204
Abstract:
The complex of a high deacetylated chitosan with Cd2+ was prepared and characterized by XPS and IR. A mechanism of adsorption of Cd2+ onto chitosan molecule is proposed that both physical adsorption and chemical adsorption occurr between Cd2+ and -NH2.
The complex of a high deacetylated chitosan with Cd2+ was prepared and characterized by XPS and IR. A mechanism of adsorption of Cd2+ onto chitosan molecule is proposed that both physical adsorption and chemical adsorption occurr between Cd2+ and -NH2.
