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1988 Volume 5 Issue 2
1988, 5(2): 1-12
Abstract:
The furan ring as a diene component in Diels-Alder reaction has been extentively studied. This paper presents a review on the intermolecular and intramolecular Diels-Alder cycloaddition reaction of the furan ring and their applications for organic synthesis.
The furan ring as a diene component in Diels-Alder reaction has been extentively studied. This paper presents a review on the intermolecular and intramolecular Diels-Alder cycloaddition reaction of the furan ring and their applications for organic synthesis.
1988, 5(2): 13-17
Abstract:
The effect of rare earth cation Ce3+ on the catalytic behaviour of multicomponent oxides consisted of PMo12Bi3Fe8-xCex K0.1Oy(x=0-8) for ammoxidation of propylenc has been investigated in a fluidized bed reactor. The structure of the catalyst was characterized by XRD, IR, SEM and TG techniques. It is found that the highest yield of aerylonitrile could be obtained at x=2-3, with Fe2(MoO4)3, Ce2(MoO4)3 and α-Bi2Oε·3MoO3 being coexisted in the catalyst. The dissolution and coagulation of the above three phases in the solid solution and the formation of a Pseudohomogeneous phase make the active component uniformly distributed at the surface and boundaries of the phases. The activity of the catalysts is considered mainly caused by synergistic effect of the individual active components. Cerium inhibits the sublimation of MoO3, stabilizing the structure, of active phases.
The effect of rare earth cation Ce3+ on the catalytic behaviour of multicomponent oxides consisted of PMo12Bi3Fe8-xCex K0.1Oy(x=0-8) for ammoxidation of propylenc has been investigated in a fluidized bed reactor. The structure of the catalyst was characterized by XRD, IR, SEM and TG techniques. It is found that the highest yield of aerylonitrile could be obtained at x=2-3, with Fe2(MoO4)3, Ce2(MoO4)3 and α-Bi2Oε·3MoO3 being coexisted in the catalyst. The dissolution and coagulation of the above three phases in the solid solution and the formation of a Pseudohomogeneous phase make the active component uniformly distributed at the surface and boundaries of the phases. The activity of the catalysts is considered mainly caused by synergistic effect of the individual active components. Cerium inhibits the sublimation of MoO3, stabilizing the structure, of active phases.
1988, 5(2): 18-22
Abstract:
The characteristic behaviour and mechanism of extraction of iron (Ⅲ) by 1-oetylnonylamine from aqueous sulfate medium were investigated, The extraction ability of this primary amine bearing secondary alkyl group was enhanced with increasing pH of the aqueous solu- tion. The extraction reaction was proved to be an endothermic process with AH value of 30.67 kJ/mol. K and 44.77 kJ/mol. K at pH 1.0 and 2.0 respectively. The extracted species are usually composed of a mixture of complexes depending on the degree of association of amine salts. The composition of the complex formed by successively extraction at pH 2.3 was estimated as (C17H35NH3)2SO4Fe(OH)SO4 which was evidenced by elemental analysis and Uv spectrometry. Molecular weight measurement indicated that this complex existed in highly intermolecular associated form in benzene solution.
The characteristic behaviour and mechanism of extraction of iron (Ⅲ) by 1-oetylnonylamine from aqueous sulfate medium were investigated, The extraction ability of this primary amine bearing secondary alkyl group was enhanced with increasing pH of the aqueous solu- tion. The extraction reaction was proved to be an endothermic process with AH value of 30.67 kJ/mol. K and 44.77 kJ/mol. K at pH 1.0 and 2.0 respectively. The extracted species are usually composed of a mixture of complexes depending on the degree of association of amine salts. The composition of the complex formed by successively extraction at pH 2.3 was estimated as (C17H35NH3)2SO4Fe(OH)SO4 which was evidenced by elemental analysis and Uv spectrometry. Molecular weight measurement indicated that this complex existed in highly intermolecular associated form in benzene solution.
1988, 5(2): 23-28
Abstract:
The chain transfer of butadiene polymerization was studied with n-butyl lithium and potassium butoxide as catalyst, toluene as solvent and chain transfer agent. The chain transfer constants to toluene with different counterions were found to be:Cs(Li)=0.11×10-3, Cs(Na)=0.40x10-3, Cs(K)=1.43x10-3, (K/Li=1.1), Cs(K)=1.26×10-3K/Li=0.5) respectively. The propagation rate constant increased 1.7 times for every 10℃ increase in temperature, and the chain transfer rate constant increased 2.1 times. The apparent activation energy of chain transfer was 62.8 kJ/mol. When increeasing K/Li from 0 to 0.5, Cs increased about 10 times, but when K/Li increased from 0.5 to 1.1, Cs changed scantly. Probably there existed certain chain transfer to monomer in this system.
The chain transfer of butadiene polymerization was studied with n-butyl lithium and potassium butoxide as catalyst, toluene as solvent and chain transfer agent. The chain transfer constants to toluene with different counterions were found to be:Cs(Li)=0.11×10-3, Cs(Na)=0.40x10-3, Cs(K)=1.43x10-3, (K/Li=1.1), Cs(K)=1.26×10-3K/Li=0.5) respectively. The propagation rate constant increased 1.7 times for every 10℃ increase in temperature, and the chain transfer rate constant increased 2.1 times. The apparent activation energy of chain transfer was 62.8 kJ/mol. When increeasing K/Li from 0 to 0.5, Cs increased about 10 times, but when K/Li increased from 0.5 to 1.1, Cs changed scantly. Probably there existed certain chain transfer to monomer in this system.
1988, 5(2): 29-33
Abstract:
In this paper the mechanism of extraction of mercury (Ⅱ) chloride by primary amine N1923 has been proposed. It shows that mercury chloride can be extracted by N1923 at pH>3.0. The composition of the extracted complex has been determined by isomolar continuous variation and saturation volume methods, IR and NMR measurements. The mechanism of the reaction is found to be as follows: HgCl2+RNH2(o)⇌RNH2·HgCl2(o) And amine acidified by hydrochloric acid can extract mercury(Ⅱ) chloride through the adduct formation 2RNH3Cl(o)+HgCl2⇌2RNH3Cl·HgCl2(o)
In this paper the mechanism of extraction of mercury (Ⅱ) chloride by primary amine N1923 has been proposed. It shows that mercury chloride can be extracted by N1923 at pH>3.0. The composition of the extracted complex has been determined by isomolar continuous variation and saturation volume methods, IR and NMR measurements. The mechanism of the reaction is found to be as follows: HgCl2+RNH2(o)⇌RNH2·HgCl2(o) And amine acidified by hydrochloric acid can extract mercury(Ⅱ) chloride through the adduct formation 2RNH3Cl(o)+HgCl2⇌2RNH3Cl·HgCl2(o)
1988, 5(2): 34-37
Abstract:
Bulk polymerization technique so far has not been successfully realized for cis-1,4 polybutadiene synthesis. In this research a type of rare earth based catalyst was developed for the synthesis of gel free polybutadicne(PB) with high cis-1,4 content. The results show that the catalyst has a higher activity than in solution polymerization and the molecular weight distribution of PB obtained in bulk polymerization is more narrow than those obtained in solution polymerization. It is also found that when the ratio of Cl/Ln is between 1.0 and 7.0 the conversion of monomer is 70% and more.
Bulk polymerization technique so far has not been successfully realized for cis-1,4 polybutadiene synthesis. In this research a type of rare earth based catalyst was developed for the synthesis of gel free polybutadicne(PB) with high cis-1,4 content. The results show that the catalyst has a higher activity than in solution polymerization and the molecular weight distribution of PB obtained in bulk polymerization is more narrow than those obtained in solution polymerization. It is also found that when the ratio of Cl/Ln is between 1.0 and 7.0 the conversion of monomer is 70% and more.
1988, 5(2): 38-43
Abstract:
The open circuit potential (O.C.P.) of the air electrode based on various carbon substrates was measured in alkaline solution. It was found that the O.C.P. not only depends on the catalyst activity for H2O2 decomposition, but also relates to the exchange current of oxygen on the carbon. The smaller the exchange current on the carbon, the greater the rate constant of the catalyst for HO2- decomposition and the more uniform the mixture of catalyst-carbon, the higher the O.C.P. of the oxygen electrode.
The open circuit potential (O.C.P.) of the air electrode based on various carbon substrates was measured in alkaline solution. It was found that the O.C.P. not only depends on the catalyst activity for H2O2 decomposition, but also relates to the exchange current of oxygen on the carbon. The smaller the exchange current on the carbon, the greater the rate constant of the catalyst for HO2- decomposition and the more uniform the mixture of catalyst-carbon, the higher the O.C.P. of the oxygen electrode.
1988, 5(2): 44-47
Abstract:
series of PET films with different degree of plannar orientation were obtained by uniaxial as well as biaxial stretching. The α peak of short-circuit thermally stimulated current was shifted to higher temperature when the degree of plannar orientation was increased. The activation energy of thermal depolarization of dipoles for main-chain segmental motion in amorphous regions was decreased linearly and the time constant τ0 of dipolar thermal relaxation was increased with the increase of the content of trans conformation.
series of PET films with different degree of plannar orientation were obtained by uniaxial as well as biaxial stretching. The α peak of short-circuit thermally stimulated current was shifted to higher temperature when the degree of plannar orientation was increased. The activation energy of thermal depolarization of dipoles for main-chain segmental motion in amorphous regions was decreased linearly and the time constant τ0 of dipolar thermal relaxation was increased with the increase of the content of trans conformation.
1988, 5(2): 48-51
Abstract:
Using FTIR the OH frequency shift △vOH for a series of tertiary butyl phenols (C6H5OH, 4-t-(CH3)3CC6H4OH, 2-t-(CH3)3CC6H4OH, 3,5-Di-t-[(CH3)C]2C6H3OH, 2,6-Di-t-[(CH3)3C]2C6H3OH] in reaction with several nitrogen and oxygen Lewis bases have been measured. The accuracy and reliability of the △vOH are pretty good. According to the relationship between △vOH and the helat of adduct formation △H, the latter is predicted. The calculated △H values were shown to be in reasonable agreement with experimental data.
Using FTIR the OH frequency shift △vOH for a series of tertiary butyl phenols (C6H5OH, 4-t-(CH3)3CC6H4OH, 2-t-(CH3)3CC6H4OH, 3,5-Di-t-[(CH3)C]2C6H3OH, 2,6-Di-t-[(CH3)3C]2C6H3OH] in reaction with several nitrogen and oxygen Lewis bases have been measured. The accuracy and reliability of the △vOH are pretty good. According to the relationship between △vOH and the helat of adduct formation △H, the latter is predicted. The calculated △H values were shown to be in reasonable agreement with experimental data.
1988, 5(2): 52-56
Abstract:
Solvent interaction with polyetheretherketone at temperature below its glass transition has been studied by using a gas chromatography method which was described by Dangayach and Bonner[9'10]. The polymer tested in this work is a novel polyetheretherketone (PEK-C) synthesized from phenolphthalein. From the GC data, a battery of 29 common compounds has been classified into solvents and nonsolvents for PEK-C. The results agreed well with experi mental data and other solubility criteria.
Solvent interaction with polyetheretherketone at temperature below its glass transition has been studied by using a gas chromatography method which was described by Dangayach and Bonner[9'10]. The polymer tested in this work is a novel polyetheretherketone (PEK-C) synthesized from phenolphthalein. From the GC data, a battery of 29 common compounds has been classified into solvents and nonsolvents for PEK-C. The results agreed well with experi mental data and other solubility criteria.
1988, 5(2): 57-61
Abstract:
The solution crosslinking condensation reaction of α,ω-bis-(dimetylamino) dimethylsiloxane oligomer with hydroxystyrene oligomer was studied. The structure and properties of the crosslinked copolymers obtained were examined by IR, DSC, WAXD, polarizing microscopy, viscosity and GPS(gas permsetectivity) etc..It was found that the crosslinked copolymers which containing certain amount of organosiloxane have two mierophases and low crystallinity showed a better permselectivity for oxygen and nitrogen. Moreover, some hydroxy-groups are remained in the macromolecule backbone of the end copolymers and they may be used for further chemical modification.
The solution crosslinking condensation reaction of α,ω-bis-(dimetylamino) dimethylsiloxane oligomer with hydroxystyrene oligomer was studied. The structure and properties of the crosslinked copolymers obtained were examined by IR, DSC, WAXD, polarizing microscopy, viscosity and GPS(gas permsetectivity) etc..It was found that the crosslinked copolymers which containing certain amount of organosiloxane have two mierophases and low crystallinity showed a better permselectivity for oxygen and nitrogen. Moreover, some hydroxy-groups are remained in the macromolecule backbone of the end copolymers and they may be used for further chemical modification.
1988, 5(2): 62-66
Abstract:
15 rare earth compounds with Tiron have been synthesized in methanol. The compositions of the compounds were determined as RET·nH2O(where T=anion of Tiron, n=3~3.5) by chemical analysis, UV, IR spectra, thermal analysis and electric conductance measurements Compounds containing light rare earth have a better blood anticoagulant activity in animal experiments than those containing heavy rare earths, with neodymium compound being the most effective.
15 rare earth compounds with Tiron have been synthesized in methanol. The compositions of the compounds were determined as RET·nH2O(where T=anion of Tiron, n=3~3.5) by chemical analysis, UV, IR spectra, thermal analysis and electric conductance measurements Compounds containing light rare earth have a better blood anticoagulant activity in animal experiments than those containing heavy rare earths, with neodymium compound being the most effective.
1988, 5(2): 67-70
Abstract:
The influence of molecular weight distribution of hydroxyl-terminated liquid polybutadiene(HTPB) on the mechanical properties of the elastomer obtained from HTPB, N, N-bis(2-hydroxypropyl) aniline and toluene diisocyanate has been investigated. The results showed that molecular weight distribution of HTPB had no marked effect on the tensile strength, 100% modulus and hardness of the elastomter. However, the permanent set of the elastomer increased obviously, when the polydispersity index of HTPB changed from 1.6 to 2.1.
The influence of molecular weight distribution of hydroxyl-terminated liquid polybutadiene(HTPB) on the mechanical properties of the elastomer obtained from HTPB, N, N-bis(2-hydroxypropyl) aniline and toluene diisocyanate has been investigated. The results showed that molecular weight distribution of HTPB had no marked effect on the tensile strength, 100% modulus and hardness of the elastomter. However, the permanent set of the elastomer increased obviously, when the polydispersity index of HTPB changed from 1.6 to 2.1.
1988, 5(2): 71-73
Abstract:
In this paper the synthesis and characteristic properties of LiAl5O8:Fe flourescence powder are reported. The effects of concentration of excited ion Fe3+ and sintering temperature on flourescence intensity have been investigated and the optimum conditions for LiAl5O8:Fe powder preparation were estabilished. The strongest flourescence peak of phosphors is at 670nm, The powder can be applied to colored and agricutural lamp production.
In this paper the synthesis and characteristic properties of LiAl5O8:Fe flourescence powder are reported. The effects of concentration of excited ion Fe3+ and sintering temperature on flourescence intensity have been investigated and the optimum conditions for LiAl5O8:Fe powder preparation were estabilished. The strongest flourescence peak of phosphors is at 670nm, The powder can be applied to colored and agricutural lamp production.
1988, 5(2): 74-76
Abstract:
By reacting polychloromethylthiirane with polyethylene Polyamincs four novel crosslinked chelating resins (PAl-4) containing thioether backbone with polyethylene polyimines in side chain were synthesized. The resins possessed excellent adsorbability for noble metal ions. The maximum adsorption capacities of the resins for Au(Ⅲ), Pd(Ⅱ), Pt(Ⅳ), Ag(Ⅰ) Zn(Ⅱ), and Pb(Ⅱ) were 1.11, 0.64, 0.68g metal/g resin and 5.07, 0.38, 0,36 mmol/g resin respectively. From the solution containing Ag(Ⅰ). Cu(Ⅱ), Zn(Ⅱ)and Cd(Ⅱ) the resins adsorpted Ag(Ⅰ) uniquely.
By reacting polychloromethylthiirane with polyethylene Polyamincs four novel crosslinked chelating resins (PAl-4) containing thioether backbone with polyethylene polyimines in side chain were synthesized. The resins possessed excellent adsorbability for noble metal ions. The maximum adsorption capacities of the resins for Au(Ⅲ), Pd(Ⅱ), Pt(Ⅳ), Ag(Ⅰ) Zn(Ⅱ), and Pb(Ⅱ) were 1.11, 0.64, 0.68g metal/g resin and 5.07, 0.38, 0,36 mmol/g resin respectively. From the solution containing Ag(Ⅰ). Cu(Ⅱ), Zn(Ⅱ)and Cd(Ⅱ) the resins adsorpted Ag(Ⅰ) uniquely.
1988, 5(2): 77-80
Abstract:
Six 3-substitute d-5(3-e thyl-4,5-diphenylthiazoline-2-ylidene)-rhodan ines were synthesized, From the sensitivty spectra it is found that 3-ethyl and 3-hydroxyethyl substituted compounds have quite good spectral sensitivities for silver halide photographic emulsions.
Six 3-substitute d-5(3-e thyl-4,5-diphenylthiazoline-2-ylidene)-rhodan ines were synthesized, From the sensitivty spectra it is found that 3-ethyl and 3-hydroxyethyl substituted compounds have quite good spectral sensitivities for silver halide photographic emulsions.
1988, 5(2): 81-83
Abstract:
The luminophors consisted of(Ca-Zn)O-Al2O3-SiO2 were prepared using asol-gel method following by activation by Eu3+ and sensitization by Bi.3+ The optimum conditions of preparation and chemical compositions of the products are confirmed through powder diffraction and flourescence measurements. The energy transfer from Bi3+ to Eu+3 is briefly discussed.
The luminophors consisted of(Ca-Zn)O-Al2O3-SiO2 were prepared using asol-gel method following by activation by Eu3+ and sensitization by Bi.3+ The optimum conditions of preparation and chemical compositions of the products are confirmed through powder diffraction and flourescence measurements. The energy transfer from Bi3+ to Eu+3 is briefly discussed.
1988, 5(2): 84-86
Abstract:
A modified formylation method of piperidine catalyzed by sulfuric acid is described. The reaction conditions and separation method of the products were presented.
A modified formylation method of piperidine catalyzed by sulfuric acid is described. The reaction conditions and separation method of the products were presented.
1988, 5(2): 87-89
Abstract:
Telomerization of isoprene with diethylamine in the presence of palladium dichloride, triphenylphosphine as catalyst produced N, N-(3,7-dimethyl-2, 7-octadienyl) diethylamine isomers, which gave a 12.7% yield of (1b) based on the isomer content under the in situ reaction with sodium prorionate.
Telomerization of isoprene with diethylamine in the presence of palladium dichloride, triphenylphosphine as catalyst produced N, N-(3,7-dimethyl-2, 7-octadienyl) diethylamine isomers, which gave a 12.7% yield of (1b) based on the isomer content under the in situ reaction with sodium prorionate.
1988, 5(2): 90-92
Abstract:
The structure of(CdxZn1-x) S:Ag obtained by sintering at 850℃ was determined by X-ray diffraction method. The solid solution is of homogeneous wurtzite over the range of 0.5 < x < 1, while the Zn-rich wurtzite structure is dominant for 0.3 < x < 0.5. With decrease of x from 0.3 to 0, the fraction of Zn-rich sphalerite increases gradually till all the structure becomes of sphalerite. The lattice parameters vary with the composition of the solution and it results in a variation of luminescence emission spectra. The phase transition from the sphalerite to wurtzite occurs at about 700℃ with simultaneous formation of the luminescence center.
The structure of(CdxZn1-x) S:Ag obtained by sintering at 850℃ was determined by X-ray diffraction method. The solid solution is of homogeneous wurtzite over the range of 0.5 < x < 1, while the Zn-rich wurtzite structure is dominant for 0.3 < x < 0.5. With decrease of x from 0.3 to 0, the fraction of Zn-rich sphalerite increases gradually till all the structure becomes of sphalerite. The lattice parameters vary with the composition of the solution and it results in a variation of luminescence emission spectra. The phase transition from the sphalerite to wurtzite occurs at about 700℃ with simultaneous formation of the luminescence center.
1988, 5(2): 93-95
Abstract:
The peak current equation for irreversible process on a spherical electrode in a stirred solution for linear sweep adsorption voltammetry, corresponding to the case of a strong adsorption, can be expressed as follows ip=ip(ta)+ip(tr)=K'vD2/3ro2v-1/6ω1/2taC*+ip(tr) where ip(ta) is the peak current for the preconcentration time(ta) in a stirred solution; ip(tr) is the peak current for the rest period, tr,v is the scan rate; D is the diffusion coefficient; ro is the radius of the spherical electrode; ω is the angular velocity of the solution; v is the kinematic viscosity, C* is the bulk concentration of the, depolarizer; K' is a constant. The equation has been verified experimentally for system of Co(Ⅱ)-dimethylglyoxime in NH3/NH4Cl.
The peak current equation for irreversible process on a spherical electrode in a stirred solution for linear sweep adsorption voltammetry, corresponding to the case of a strong adsorption, can be expressed as follows ip=ip(ta)+ip(tr)=K'vD2/3ro2v-1/6ω1/2taC*+ip(tr) where ip(ta) is the peak current for the preconcentration time(ta) in a stirred solution; ip(tr) is the peak current for the rest period, tr,v is the scan rate; D is the diffusion coefficient; ro is the radius of the spherical electrode; ω is the angular velocity of the solution; v is the kinematic viscosity, C* is the bulk concentration of the, depolarizer; K' is a constant. The equation has been verified experimentally for system of Co(Ⅱ)-dimethylglyoxime in NH3/NH4Cl.
1988, 5(2): 96-99
Abstract:
Four novel complexcs were obtained by reaoting H2PtCl6·6H2O or Na2PtCl6 with 18 Crown-6 and 1, 7, 10, 16-tetraoxa-4, 13-diazacyclooctadecane in molar ratio of 1:2 and 1:1 respectively. The complexes arc stable and slightsoluble or unsoluble in common organic solvents. In hydrosilylation of unsaturated compounds the complexes show a high catalytic activity at 80℃ and can be recovered and reused for several times. The activity of the complexes are, however, lower than that of H2PtCl6 or Na2PtCl6 alone when the hydrosilylation is carried out at 40℃ or room temperature.
Four novel complexcs were obtained by reaoting H2PtCl6·6H2O or Na2PtCl6 with 18 Crown-6 and 1, 7, 10, 16-tetraoxa-4, 13-diazacyclooctadecane in molar ratio of 1:2 and 1:1 respectively. The complexes arc stable and slightsoluble or unsoluble in common organic solvents. In hydrosilylation of unsaturated compounds the complexes show a high catalytic activity at 80℃ and can be recovered and reused for several times. The activity of the complexes are, however, lower than that of H2PtCl6 or Na2PtCl6 alone when the hydrosilylation is carried out at 40℃ or room temperature.
