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2004 Volume 21 Issue 6
2004, 21(6): 541-545
Abstract:
The structure, kinds and applications of metalloporphyrins are introduced in this paper. The recent researches on the biomimetic oxidation of alkanes catalyzed by metalloporphyrins are reviewed with the emphasis on the oxidation of cyclohexane to cyclohexanone by air. It is the first case of the industrial biomimetic oxidation for hydrocarbon with air using metalloporphyrins as catalyst.
The structure, kinds and applications of metalloporphyrins are introduced in this paper. The recent researches on the biomimetic oxidation of alkanes catalyzed by metalloporphyrins are reviewed with the emphasis on the oxidation of cyclohexane to cyclohexanone by air. It is the first case of the industrial biomimetic oxidation for hydrocarbon with air using metalloporphyrins as catalyst.
2004, 21(6): 546-550
Abstract:
The formation of hydroxyl radicals on photolysis of Fe(Ⅲ)-citrate complex in aqueous solution was identified by using benzene as scavenger. The decolorization of an azo dye Orange Ⅱ in aqueous solution was then investigated in the presence of Fe(Ⅲ)-citrate complex. The results indicate that a solution of 8 mg/L OrangeⅡ could be decolorized with an efficiency of 60%~70% under the illumination with a high-pressure mercury lamp(125 W, λ≥365 nm) in an hour. The decolorization of dye at the concentration ranged in 8~50 mg/L was in accordance with pseudo-first order law reaction, and the decolorization rate decreased with increase of the initial dye concentration. The comparatively higher decolorization efficiency was achieved at pH values of 4~6. At a given concentration of ferric ions, the decolorization was faster when the Fe(Ⅲ)/citrate ratio was less 1, and the decolorization efficiency increased with increase of the citrate ions.
The formation of hydroxyl radicals on photolysis of Fe(Ⅲ)-citrate complex in aqueous solution was identified by using benzene as scavenger. The decolorization of an azo dye Orange Ⅱ in aqueous solution was then investigated in the presence of Fe(Ⅲ)-citrate complex. The results indicate that a solution of 8 mg/L OrangeⅡ could be decolorized with an efficiency of 60%~70% under the illumination with a high-pressure mercury lamp(125 W, λ≥365 nm) in an hour. The decolorization of dye at the concentration ranged in 8~50 mg/L was in accordance with pseudo-first order law reaction, and the decolorization rate decreased with increase of the initial dye concentration. The comparatively higher decolorization efficiency was achieved at pH values of 4~6. At a given concentration of ferric ions, the decolorization was faster when the Fe(Ⅲ)/citrate ratio was less 1, and the decolorization efficiency increased with increase of the citrate ions.
2004, 21(6): 551-555
Abstract:
Six heteropoly complexes M3H2[PW9(NbO2)3O37]·xH2O and M4-mHm[PW9Nb3O40]·xH2O(M=(CH3)4N+, (C4H9)4N+,(C2H5)4N+,(C7H15)4N+) were synthesized and characterized. IR, UV spectrometry, polarography and chemical titration confirmed the existence of NbO2 groups in the complexes. All their 183W NMR spectra have six peaks, showing the Keggin structure of anions in the compounds. Oxidation of maleic acid into tartaric acid showed that the complexes containing peroxy ions exhibited higher catalytic activity than those without peroxy ions.
Six heteropoly complexes M3H2[PW9(NbO2)3O37]·xH2O and M4-mHm[PW9Nb3O40]·xH2O(M=(CH3)4N
2004, 21(6): 556-560
Abstract:
The hydrophobically associating acrylamide/dibutylacrylamide(AM/DBA) copolymers were synthesized by aqueous micellar polymerization for Enhanced Oil Recovery(EOR). The effects of hydrophobe and surfactant content on the dissolution behavior of the copolymers have been investigated. The results show that when the mass fraction of hydrophobic monomer was between 0.8% and 1.0%, and the NH value was between 8 and 10, the copolymers showed both good solubility and salt-tolerance, and their filter ratio were less than 2. The contradiction between solubility and salt-tolerance of copolymers could be well settled e.g. the copolymer having intrinsic viscosity exceeding 22 dL/g can be dissolved in water for 2 h giving the solutions characteristic of salt-viscosifying.
The hydrophobically associating acrylamide/dibutylacrylamide(AM/DBA) copolymers were synthesized by aqueous micellar polymerization for Enhanced Oil Recovery(EOR). The effects of hydrophobe and surfactant content on the dissolution behavior of the copolymers have been investigated. The results show that when the mass fraction of hydrophobic monomer was between 0.8% and 1.0%, and the NH value was between 8 and 10, the copolymers showed both good solubility and salt-tolerance, and their filter ratio were less than 2. The contradiction between solubility and salt-tolerance of copolymers could be well settled e.g. the copolymer having intrinsic viscosity exceeding 22 dL/g can be dissolved in water for 2 h giving the solutions characteristic of salt-viscosifying.
2004, 21(6): 561-565
Abstract:
Twenty 1,3,4-oxadiazole sulfurethers(3a~3j) and corresponding sulfone derivatives(4a~4j) were synthesized via condensation of 1,3,4-oxadiazole chloromethane(1) with the corresponding 1,3,4-oxadiazole thiols(2a~2j) followed by oxidation with 30% H2O2 in the presence of catalyst Na2WO4, and their structures were confirmed by IR, 1H NMR, MS and elemental analysis. Among the compounds synthesized, the sulfurether compounds (3b) and (3h) exhibited considerably strong inhibiting activity to Staphylococcus aureus and Proteus vulgaris in dosage of 1.0×10-4(mass fraction), the sulfone compounds 4b, 4c, 4d and 4f exhibited mediumly inhibiting activity to Escherichia.coli, whereas the other compounds showed weak or even no antibacterial activity.
Twenty 1,3,4-oxadiazole sulfurethers(3a~3j) and corresponding sulfone derivatives(4a~4j) were synthesized via condensation of 1,3,4-oxadiazole chloromethane(1) with the corresponding 1,3,4-oxadiazole thiols(2a~2j) followed by oxidation with 30% H2O2 in the presence of catalyst Na2WO4, and their structures were confirmed by IR, 1H NMR, MS and elemental analysis. Among the compounds synthesized, the sulfurether compounds (3b) and (3h) exhibited considerably strong inhibiting activity to Staphylococcus aureus and Proteus vulgaris in dosage of 1.0×10-4(mass fraction), the sulfone compounds 4b, 4c, 4d and 4f exhibited mediumly inhibiting activity to Escherichia.coli, whereas the other compounds showed weak or even no antibacterial activity.
2004, 21(6): 566-570
Abstract:
A poly(acridine red) modified electrode(PARME) was prepared on a glassy carbon electrode by cyclic voltammetry. The electrode has an excellent electrocatalytic activity for the oxidation of p-acetamido-phenol(PRCT). A couple of sensitive and reversible redox peaks were recorded in the cyclic voltammograms. The oxidation peak potential was reduced by 200 mV compared with that on the bare GCE. The oxidation peak current was linearly dependent on the concentration of PRCT in the range of 0.20~9.00 μmol/L and 0.02~0.20 mmol/L with detection limit of 2.00×10-3 μmol/L. No change in electrochemical properties of PARME was observed after repeated use for 45 d at ambient temperature.
A poly(acridine red) modified electrode(PARME) was prepared on a glassy carbon electrode by cyclic voltammetry. The electrode has an excellent electrocatalytic activity for the oxidation of p-acetamido-phenol(PRCT). A couple of sensitive and reversible redox peaks were recorded in the cyclic voltammograms. The oxidation peak potential was reduced by 200 mV compared with that on the bare GCE. The oxidation peak current was linearly dependent on the concentration of PRCT in the range of 0.20~9.00 μmol/L and 0.02~0.20 mmol/L with detection limit of 2.00×10-3 μmol/L. No change in electrochemical properties of PARME was observed after repeated use for 45 d at ambient temperature.
2004, 21(6): 571-575
Abstract:
The "linear reactor" made by polyethylene glycol(PEG) and water was used to assembly a series of one-dimension nano-sized crystals of title compound in various lengths(200 nm~2.2 μm) and diameters(20~60 nm). The length and diameters of the nanocrystals could be adjusted by changing the molecular weight of PEG and the content of water in the system. The main phase of the nanocrystal formed in reactor is found to be identical with that of the single crystal self-assembled in water. The analysis of X-ray single-crystal diffraction revealed that the donor atoms in the equatorial plane of the square pyramid geometry configuration of copper ion are imino nitrogen atom and two carboxylate oxygen atom from two different ligands and a water molecule is located in the axial position. The adjacent structural units are connected through the coordination of carboxylic oxygen from iminodiacetic acid with Cu(Ⅱ) to form one-dimension zigzag chain structure, and the definite chains construct a one-dimension nanocrystal through hydrogen-bondings.
The "linear reactor" made by polyethylene glycol(PEG) and water was used to assembly a series of one-dimension nano-sized crystals of title compound in various lengths(200 nm~2.2 μm) and diameters(20~60 nm). The length and diameters of the nanocrystals could be adjusted by changing the molecular weight of PEG and the content of water in the system. The main phase of the nanocrystal formed in reactor is found to be identical with that of the single crystal self-assembled in water. The analysis of X-ray single-crystal diffraction revealed that the donor atoms in the equatorial plane of the square pyramid geometry configuration of copper ion are imino nitrogen atom and two carboxylate oxygen atom from two different ligands and a water molecule is located in the axial position. The adjacent structural units are connected through the coordination of carboxylic oxygen from iminodiacetic acid with Cu(Ⅱ) to form one-dimension zigzag chain structure, and the definite chains construct a one-dimension nanocrystal through hydrogen-bondings.
2004, 21(6): 576-580
Abstract:
Electroless plating NiZnP alloys have been obtained from the bath having boric acid as a buffer agent and sodium citrate as a complexing agent. The effects of deposition parameters, such as pH and mole ratios of ZnSO4 to (ZnSO4+NiSO4) on the plating rate, coating composition, structure, surface morphology and corrosion resistance of the alloys were examined. It was found that the presence of zinc sulfate in the bath has an inhibitory effect on the alloy deposition. As a consequence, the percentage of zinc in the deposits never reaches values higher than at.20%. The structure and surface morphology were charactered by XRD, TEM and SEM. The NiZnP alloy consists of amorphous phase together with little cubic nickel phase, and its surface morphology depencdes on the deposition variables. The corrosion resistance of the NiZnP deposits in ω(NaCl)=3.5% solution(pH=7.0) was studied by mass loss test and electrochemical anodic polarization measurement. The results show that the depo sits plated at different deposition condition have different corrosion resistance and the deposits with higher percentage of zinc and less percentage of phosphorus have better resistance corrosion than that with less percentage of zinc and higher percentage of phosphorus. The results of mass loss tests were basically in accordance with that from electrochemical anodic polarization measurements.
Electroless plating NiZnP alloys have been obtained from the bath having boric acid as a buffer agent and sodium citrate as a complexing agent. The effects of deposition parameters, such as pH and mole ratios of ZnSO4 to (ZnSO4+NiSO4) on the plating rate, coating composition, structure, surface morphology and corrosion resistance of the alloys were examined. It was found that the presence of zinc sulfate in the bath has an inhibitory effect on the alloy deposition. As a consequence, the percentage of zinc in the deposits never reaches values higher than at.20%. The structure and surface morphology were charactered by XRD, TEM and SEM. The NiZnP alloy consists of amorphous phase together with little cubic nickel phase, and its surface morphology depencdes on the deposition variables. The corrosion resistance of the NiZnP deposits in ω(NaCl)=3.5% solution(pH=7.0) was studied by mass loss test and electrochemical anodic polarization measurement. The results show that the depo sits plated at different deposition condition have different corrosion resistance and the deposits with higher percentage of zinc and less percentage of phosphorus have better resistance corrosion than that with less percentage of zinc and higher percentage of phosphorus. The results of mass loss tests were basically in accordance with that from electrochemical anodic polarization measurements.
2004, 21(6): 581-584
Abstract:
3-Thioformylindolizines derivatives were condensed with 1,2-dimethylquinolinium iodide or 1,4-dimethylquinolinium iodide, respectively, in the presence of piperidine to give a series of dimethine-cyanines containing indolizine ring. Their structures were comfirmed by elemental analysis, IR, 1H NMR and MS spectroscopy. The fluorescence properties of the compounds in the solid state were studied. Their luminescence properties in solid state were determined preliminary. The results showed that nine compounds 5a, 5b, 5c, 5d, 5e, and 6a, 6d, 6e and 6f exhibited emission wavelengths above 400 nm, showing potential applications in luminescent materials.
3-Thioformylindolizines derivatives were condensed with 1,2-dimethylquinolinium iodide or 1,4-dimethylquinolinium iodide, respectively, in the presence of piperidine to give a series of dimethine-cyanines containing indolizine ring. Their structures were comfirmed by elemental analysis, IR, 1H NMR and MS spectroscopy. The fluorescence properties of the compounds in the solid state were studied. Their luminescence properties in solid state were determined preliminary. The results showed that nine compounds 5a, 5b, 5c, 5d, 5e, and 6a, 6d, 6e and 6f exhibited emission wavelengths above 400 nm, showing potential applications in luminescent materials.
2004, 21(6): 585-588
Abstract:
The complex of methionine with Zn(Met)Ac2·H2O was prepared in a water-acetone mixture. Its composition was identified as Zn(Met)Ac2·H2O by chemical and elemental analyses. The structure and thermal stability of the complex were investigated by IR, DSC and TG-DTG, its enthalpies in dehydrolysis and decomposition courses were obtained as 15.30 J/g and 357.80 J/g, respectively. The constant volume combustion energy of the complex, ΔcE, was determined as (-6 472.11±2.20) kJ/mol by a precise rotating-bomb calorimeter at 298.15 K, its standard enthalpy of combustion, ΔcHmθ, and standard enthalpy of formation, ΔfHmθ, were calculated as (-6 475.21±2.20) kJ/mol and (-429.04±2.59) kJ/mol, respectively.
The complex of methionine with Zn(Met)Ac2·H2O was prepared in a water-acetone mixture. Its composition was identified as Zn(Met)Ac2·H2O by chemical and elemental analyses. The structure and thermal stability of the complex were investigated by IR, DSC and TG-DTG, its enthalpies in dehydrolysis and decomposition courses were obtained as 15.30 J/g and 357.80 J/g, respectively. The constant volume combustion energy of the complex, ΔcE, was determined as (-6 472.11±2.20) kJ/mol by a precise rotating-bomb calorimeter at 298.15 K, its standard enthalpy of combustion, ΔcHmθ, and standard enthalpy of formation, ΔfHmθ, were calculated as (-6 475.21±2.20) kJ/mol and (-429.04±2.59) kJ/mol, respectively.
2004, 21(6): 589-592
Abstract:
Pressure behavior and pressure effect of dilute stabilizing agents in the thermal decomposition of organic peroxides were examined in a mini-closed pressure vessel test(MCPVT). The maximal pressure of thermal decomposition(Pmax) reduced when stabilizing agent was non-volatile, and Pmax increased when stabilizing agent was a volatile, and (dP/dt)max was reduced. The stabilizing effects of stabilizing agent on the thermal decomposition were evaluated with (dP/dt)max and K(K=(dP/dt)max,D/(dP/dt)max(D:dilute stabilizing agent). The order of K was BPO-H2 < ODCP-CaCO3 < DTBP-IPS < TBPB-IPS, when mass fraction of organic peroxides was 0.6 and K was equal to 0.748 2, 0.316 1, 0.242 3, 0.182 7.
Pressure behavior and pressure effect of dilute stabilizing agents in the thermal decomposition of organic peroxides were examined in a mini-closed pressure vessel test(MCPVT). The maximal pressure of thermal decomposition(Pmax) reduced when stabilizing agent was non-volatile, and Pmax increased when stabilizing agent was a volatile, and (dP/dt)max was reduced. The stabilizing effects of stabilizing agent on the thermal decomposition were evaluated with (dP/dt)max and K(K=(dP/dt)max,D/(dP/dt)max(D:dilute stabilizing agent). The order of K was BPO-H2 < ODCP-CaCO3 < DTBP-IPS < TBPB-IPS, when mass fraction of organic peroxides was 0.6 and K was equal to 0.748 2, 0.316 1, 0.242 3, 0.182 7.
2004, 21(6): 593-596
Abstract:
The effects of three kinds of surfactants(dodecyl sodium sulfate, Xinjiang petroleum sulfonate, Shengli petroleum sulfonate) and oil property on the microemulsion phase diagrams have been studied by emulsibility, i.e. E value, which is difined as the ratio of middle phase area to the total area of three phases in the phase diagrams. The results show that both surfactant and property of oil greatly affect the microemulsion phase diagrams. For Xinjiang petroleum sulfonate, the middle phase has the biggest height, but the smallest salt breadth, its Evalue is 0.378; for Shengli petroleum sulfonate, the microemulsion phase diagram is always consisted of three phases, where the salt breadth is very large, but the smallest height of middle phase, its E value is 0.112; for dodecyl sodium sulfate, the height of middle phase and salt breadth are medium, and E value is 0.201. For crude higher oil content in oil phase, its E value is small and salt breadth is greater.
The effects of three kinds of surfactants(dodecyl sodium sulfate, Xinjiang petroleum sulfonate, Shengli petroleum sulfonate) and oil property on the microemulsion phase diagrams have been studied by emulsibility, i.e. E value, which is difined as the ratio of middle phase area to the total area of three phases in the phase diagrams. The results show that both surfactant and property of oil greatly affect the microemulsion phase diagrams. For Xinjiang petroleum sulfonate, the middle phase has the biggest height, but the smallest salt breadth, its Evalue is 0.378; for Shengli petroleum sulfonate, the microemulsion phase diagram is always consisted of three phases, where the salt breadth is very large, but the smallest height of middle phase, its E value is 0.112; for dodecyl sodium sulfate, the height of middle phase and salt breadth are medium, and E value is 0.201. For crude higher oil content in oil phase, its E value is small and salt breadth is greater.
2004, 21(6): 597-600
Abstract:
A kind of absorbent is made from the combination of chitosan and bentonite. The absorbent is used for absorption of tannic acid in Chinese medicines, decolorization of used dyestuff solution, and clarification of old vinegar. The decolorization rate is 97%. The absorption rate of tannic acid is 50%. The transmittance of old vinegar is 25.8%. The structure change of bentonite and the mechanism of modification are discussed based on XRD results that the structure of bentonite does not changed and chitosan is absorbed on the surface of bentonite.
A kind of absorbent is made from the combination of chitosan and bentonite. The absorbent is used for absorption of tannic acid in Chinese medicines, decolorization of used dyestuff solution, and clarification of old vinegar. The decolorization rate is 97%. The absorption rate of tannic acid is 50%. The transmittance of old vinegar is 25.8%. The structure change of bentonite and the mechanism of modification are discussed based on XRD results that the structure of bentonite does not changed and chitosan is absorbed on the surface of bentonite.
2004, 21(6): 601-604
Abstract:
HZSM-5 zeolite was modified by silicone oil through chemical liquid deposition(CLD). The modified zeolite were characterized and examined by IR, nitrogen adsorption, and in the reactions of metaxylene isomerization and 1,3,5-triisopropylbenzene(1,3,5-TIPB) cracking. The results showed that the framework and micropore structure of HZSM-5 zeolite remained unchanged and the sizes of open pore in zeolite were reduced and the Brφnsted acidity values on external surface were inactivated. The mechanism of silica modification has been briefly discussed.
HZSM-5 zeolite was modified by silicone oil through chemical liquid deposition(CLD). The modified zeolite were characterized and examined by IR, nitrogen adsorption, and in the reactions of metaxylene isomerization and 1,3,5-triisopropylbenzene(1,3,5-TIPB) cracking. The results showed that the framework and micropore structure of HZSM-5 zeolite remained unchanged and the sizes of open pore in zeolite were reduced and the Brφnsted acidity values on external surface were inactivated. The mechanism of silica modification has been briefly discussed.
2004, 21(6): 605-608
Abstract:
Nano-Bi-Ni mixed oxides were prepared by solid-state reaction and characterized by XRD and TEM. The results showed that the oxides consisted of monoclinic Bi2O3 and rhombohedral NiO with particle diameter being in range from 15 to 45 nm. Electrochemical measurements showed that the deep discharge capacity of electrode doped with nano-Bi-Ni mixed oxides at a specific current of 95 mA/g was increased by about 35%.
Nano-Bi-Ni mixed oxides were prepared by solid-state reaction and characterized by XRD and TEM. The results showed that the oxides consisted of monoclinic Bi2O3 and rhombohedral NiO with particle diameter being in range from 15 to 45 nm. Electrochemical measurements showed that the deep discharge capacity of electrode doped with nano-Bi-Ni mixed oxides at a specific current of 95 mA/g was increased by about 35%.
2004, 21(6): 609-612
Abstract:
Three DAR cyan couplers(6) were synthesized based on 1-hydroxyl-N-{4-(2,4-di-tert-phenylphenoxyl)-butyl}-2-naphthamide. Linking group is 2,5-dimercapto-1,3,4-thiociazole, and 1-formyl-2-(4-aminophenyl)hydrazine, 1-acetyl-2-(4-aminophenyl)hydrazine and 1-trifluoacyl-2-(4-aminophenyl)hydrazine are the accelerator. The structures of the couplers are identified by IR, 1H NMR, MS and elemental analysis.
Three DAR cyan couplers(6) were synthesized based on 1-hydroxyl-N-{4-(2,4-di-tert-phenylphenoxyl)-butyl}-2-naphthamide. Linking group is 2,5-dimercapto-1,3,4-thiociazole, and 1-formyl-2-(4-aminophenyl)hydrazine, 1-acetyl-2-(4-aminophenyl)hydrazine and 1-trifluoacyl-2-(4-aminophenyl)hydrazine are the accelerator. The structures of the couplers are identified by IR, 1H NMR, MS and elemental analysis.
2004, 21(6): 613-616
Abstract:
A secondary battery system of polyanline(PAn) film/acidic molten salt/aluminm has been developed based on a room temperature molten salt, N-butylpyridinium choride(Bupycl) and aluminum chloride. The results indicate that the open-circuit voltage is about 1.35 V and its coulombic efficiency of charging-discharging cycle achieves 90% at a current density of 8.0×10-5 A/cm2. No sensible change was observed after twenty cyclings.
A secondary battery system of polyanline(PAn) film/acidic molten salt/aluminm has been developed based on a room temperature molten salt, N-butylpyridinium choride(Bupycl) and aluminum chloride. The results indicate that the open-circuit voltage is about 1.35 V and its coulombic efficiency of charging-discharging cycle achieves 90% at a current density of 8.0×10-5 A/cm2. No sensible change was observed after twenty cyclings.
2004, 21(6): 617-620
Abstract:
Copper methanesulfonate was synthesized and used as a catalyst in the esterification of n-butyric acid with isoamyl alcohol. The results showed that at the condition of 1.2:1 molar ratio of isoamyl alcohol to n-butyric acid, 0.5% catalyst(molar percent of n-butyric acid), 2.5 h, no water-carrying agent, at reflux temperature, the esterification degree achieved 95.8%. Copper methanesulfonate can be reused by simple phase-separation, no need of regeneration. It has merits of both homogeneous and heterogeneous catalyst. The catalytic activities of different Lewis acids were compared with it.
Copper methanesulfonate was synthesized and used as a catalyst in the esterification of n-butyric acid with isoamyl alcohol. The results showed that at the condition of 1.2:1 molar ratio of isoamyl alcohol to n-butyric acid, 0.5% catalyst(molar percent of n-butyric acid), 2.5 h, no water-carrying agent, at reflux temperature, the esterification degree achieved 95.8%. Copper methanesulfonate can be reused by simple phase-separation, no need of regeneration. It has merits of both homogeneous and heterogeneous catalyst. The catalytic activities of different Lewis acids were compared with it.
2004, 21(6): 621-624
Abstract:
The binding reactions of enoxacin with bovine serum albumin(BSA) or chicken egg albumin(CEA) in aqueous solution were studied by fluorescence and UV-Vis absorption spectrometry. The results indicated that enoxacin could bind with BSA or CEA strongly at molar ratio 1:1 and the equilibrium constants were KBSA=8.02×104 L/mol and KCEA=4.51×104 L/mol, respectively. The action distances(rBSA=2.52 nm, rCEA=2.74 nm) and energy transfer efficiencies(EBSA=0.54, ECEA=0.52) between donor(BSA,CEA) and acceptor(enoxacin) were calculated according to F9 rster's nonradiative energy transfer mechanism. Good linear Stern-Volmer lines were observed on the fluorescence of BSA or CEA quenched by enoxacin of different concentration, indicating the combination reaction of enoxacin with BSA or CEA is a single static quenching process.
The binding reactions of enoxacin with bovine serum albumin(BSA) or chicken egg albumin(CEA) in aqueous solution were studied by fluorescence and UV-Vis absorption spectrometry. The results indicated that enoxacin could bind with BSA or CEA strongly at molar ratio 1:1 and the equilibrium constants were KBSA=8.02×104 L/mol and KCEA=4.51×104 L/mol, respectively. The action distances(rBSA=2.52 nm, rCEA=2.74 nm) and energy transfer efficiencies(EBSA=0.54, ECEA=0.52) between donor(BSA,CEA) and acceptor(enoxacin) were calculated according to F9 rster's nonradiative energy transfer mechanism. Good linear Stern-Volmer lines were observed on the fluorescence of BSA or CEA quenched by enoxacin of different concentration, indicating the combination reaction of enoxacin with BSA or CEA is a single static quenching process.
2004, 21(6): 625-628
Abstract:
A novel AB2 type monomer, N-(3,5-diaminobenzoyl)glycine was synthesized in two-steps. A hyperbranched polyamide(2a) was prepared from this new monomer by self-polycondensation, and five hyperbranched polymers(2b~2f) with various end-groups were prepared by end-capping reactions of 2a with acetic anhydride or acid chlorides. The six polymers were characterized by FTIR, 1H NMR, DSC and TGA.
A novel AB2 type monomer, N-(3,5-diaminobenzoyl)glycine was synthesized in two-steps. A hyperbranched polyamide(2a) was prepared from this new monomer by self-polycondensation, and five hyperbranched polymers(2b~2f) with various end-groups were prepared by end-capping reactions of 2a with acetic anhydride or acid chlorides. The six polymers were characterized by FTIR, 1H NMR, DSC and TGA.
2004, 21(6): 629-632
Abstract:
A series of modified polyurethane preoligomers with different amino siloxane content were synthesized by reaction of aminoethyl-aminopropyl poly(dimethyl siloxane)(AEAPS) with toluene diisocyanate and polyoxypropylene glycol and characterized by FT-IR. The modified polyurethane materials were prepared by the reacting the preoligomers with curing agent 3,3'-dichloro-4,4'-diamino-diphenylmethane(MOCA). The properties of materials were examined by stress-strain analysis, thermal resistance analysis and surface water contact angle measurement. The siloxane modified polyurethanes with 10%(mass fraction) AEAPS revealed the best comprehensive properties in comparison with the pure polyurethanes, the strain and stress were improved by 31% and 52% respectively, and the water contact angle increased by 23°.
A series of modified polyurethane preoligomers with different amino siloxane content were synthesized by reaction of aminoethyl-aminopropyl poly(dimethyl siloxane)(AEAPS) with toluene diisocyanate and polyoxypropylene glycol and characterized by FT-IR. The modified polyurethane materials were prepared by the reacting the preoligomers with curing agent 3,3'-dichloro-4,4'-diamino-diphenylmethane(MOCA). The properties of materials were examined by stress-strain analysis, thermal resistance analysis and surface water contact angle measurement. The siloxane modified polyurethanes with 10%(mass fraction) AEAPS revealed the best comprehensive properties in comparison with the pure polyurethanes, the strain and stress were improved by 31% and 52% respectively, and the water contact angle increased by 23°.
2004, 21(6): 633-636
Abstract:
The electrooxidation of methanol on a carbon-supported PtRuMo catalysts prepared by liquid-phase NaBH4 reduction method has been investigated. The stripping current of saturated-adsorption CO is defined as normalization activity toward methanol oxidation. The effects of methanol concentration and temperature on the catalytic activity in a half-cell containing sulfuric acid electrolyte was studied. The optimal molar ratio of Pt to Ru to Mo was found to be 1:0.5:1. The catalyst had high activity at ambient temperature and its activity increased with the increase of temperature. The optimal methanol concentration was 1.0~2.0 mol/L at ambient temperature.
The electrooxidation of methanol on a carbon-supported PtRuMo catalysts prepared by liquid-phase NaBH4 reduction method has been investigated. The stripping current of saturated-adsorption CO is defined as normalization activity toward methanol oxidation. The effects of methanol concentration and temperature on the catalytic activity in a half-cell containing sulfuric acid electrolyte was studied. The optimal molar ratio of Pt to Ru to Mo was found to be 1:0.5:1. The catalyst had high activity at ambient temperature and its activity increased with the increase of temperature. The optimal methanol concentration was 1.0~2.0 mol/L at ambient temperature.
2004, 21(6): 637-640
Abstract:
Lys(z)-NCA was synthesized from Nε-carbobenzoyloxy-L-Lysine and triphosgene in THF. Amphiphilic triblock copolymers poly(Nε-carbobenzyloxy-L-Lysine)(poly(Nε-CBZ-Lysine)-PEG-poly(Nε-CBZ-Lysine)) were synthesized in DMF in the condition that both amino-end PEG was used as initiator. The structures of the block copolymers were characterized by IR, 1H NMR, GPC and DSC. The results revealed that triblock copolymers with controlled Mn and narrow molecular weight distribution(Ip=1.06) were synthesized, the yield was 95.4%. These block copolymers are expected to have promising application in the field of biomaterials for the two components in block copolymers are both biocompatible.
Lys(z)-NCA was synthesized from Nε-carbobenzoyloxy-L-Lysine and triphosgene in THF. Amphiphilic triblock copolymers poly(Nε-carbobenzyloxy-L-Lysine)(poly(Nε-CBZ-Lysine)-PEG-poly(Nε-CBZ-Lysine)) were synthesized in DMF in the condition that both amino-end PEG was used as initiator. The structures of the block copolymers were characterized by IR, 1H NMR, GPC and DSC. The results revealed that triblock copolymers with controlled Mn and narrow molecular weight distribution(Ip=1.06) were synthesized, the yield was 95.4%. These block copolymers are expected to have promising application in the field of biomaterials for the two components in block copolymers are both biocompatible.
2004, 21(6): 641-643
Abstract:
(4R)-Hydroxy-(S)-proline was N-protected by reaction with di-tert-butyl pyrocarbonate to give N-Boc-(4R)-hydroxy-(S)-proline, which was treated with NaH in anhydrous tetrahydrofuran and followed by etherification with PhCH2Br to form the N-Boc-(4R)-benzyloxy-(S)-proline, which, after removal of the protecting group with CF3COOH gave the title compound. As an efficient catalyst for the direct asymmetryic aldol reaction the compound gave products in yield ranged from 58% to 77% with enantiomeric excess up to 88%.
(4R)-Hydroxy-(S)-proline was N-protected by reaction with di-tert-butyl pyrocarbonate to give N-Boc-(4R)-hydroxy-(S)-proline, which was treated with NaH in anhydrous tetrahydrofuran and followed by etherification with PhCH2Br to form the N-Boc-(4R)-benzyloxy-(S)-proline, which, after removal of the protecting group with CF3COOH gave the title compound. As an efficient catalyst for the direct asymmetryic aldol reaction the compound gave products in yield ranged from 58% to 77% with enantiomeric excess up to 88%.
2004, 21(6): 644-645
Abstract:
The infrared spectrum of pyridine adsorbed on surface of ZnSO4·7H2O indicates it exhibits Lewis acid centers as a catalyst. Experiments showed that it had good catalytic performance in esterification of oxalic acid with iso-amyl alcohol with ester yield being 97.5% in following conditions:the molar ratio of isoamyl alcohol to oxalic acid 2.8, catalyst amount 7.4%(based on the mass of oxalic acid), reaction temperature 145℃, reaction time 1.5 h. The catalyst could be used repeatedly for six times.
The infrared spectrum of pyridine adsorbed on surface of ZnSO4·7H2O indicates it exhibits Lewis acid centers as a catalyst. Experiments showed that it had good catalytic performance in esterification of oxalic acid with iso-amyl alcohol with ester yield being 97.5% in following conditions:the molar ratio of isoamyl alcohol to oxalic acid 2.8, catalyst amount 7.4%(based on the mass of oxalic acid), reaction temperature 145℃, reaction time 1.5 h. The catalyst could be used repeatedly for six times.
2004, 21(6): 646-648
Abstract:
PEG-stabilized platinum nanoparticles with uniform size were prepared successfully. They did not precipitate after being stored for four months. The nanoparticles show high catalytic activity for hydrogenation of styrene and selectivity of long chain olefins. The platinum nanoparticles modified by cinchonidine give 85.6% e.e selectivity in asymmetric hydrogenation of ethyl pyruvate.
PEG-stabilized platinum nanoparticles with uniform size were prepared successfully. They did not precipitate after being stored for four months. The nanoparticles show high catalytic activity for hydrogenation of styrene and selectivity of long chain olefins. The platinum nanoparticles modified by cinchonidine give 85.6% e.e selectivity in asymmetric hydrogenation of ethyl pyruvate.
