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2015 Volume 32 Issue 3
2015, 32(3): 245-254
doi: 10.11944/j.issn.1000-0518.2015.03.140236
Abstract:
Polyoxo molybdates(POMs) have potential applications in photoelectrochemistry, magnetism,catalysis(photo-and electronic),materials science and biomedicine due to the diversity of the chemistry,structure and electron. In recent years,layer-by-layer self-assembly method has been widely used to build ultra thin films from POMs,which extends the application range of POMs. This work reviews the research progress of functional polyoxometalate-based composite materials(including plate multilayer films,microspheres and magnetic vesicles) via the layer-by-layer self-assembly. The applications in electrocatalysis,photocatalysis,electrochromism gas sensor and magnetic properties are also introduced. The research perspectives are presented.
Polyoxo molybdates(POMs) have potential applications in photoelectrochemistry, magnetism,catalysis(photo-and electronic),materials science and biomedicine due to the diversity of the chemistry,structure and electron. In recent years,layer-by-layer self-assembly method has been widely used to build ultra thin films from POMs,which extends the application range of POMs. This work reviews the research progress of functional polyoxometalate-based composite materials(including plate multilayer films,microspheres and magnetic vesicles) via the layer-by-layer self-assembly. The applications in electrocatalysis,photocatalysis,electrochromism gas sensor and magnetic properties are also introduced. The research perspectives are presented.
2015, 32(3): 255-260
doi: 10.11944/j.issn.1000-0518.2015.03.140207
Abstract:
3-Butenyl-based liquid crystals are a new series of liquid crystals with low melting point and high clearing point. A new synthetic method for key intermediate aryl boric acid was improved via Arbuzov,WittigHorner,catalytic hydrogenation and lithiation-boric acid 4-step reactions by using 3-fluorobenzyl chloride as the starting material. Isomerization of trans-cyclohexane and defluorination side reactions were avoided. After optimization the total yield was improved from 4.5% to 30%,which is valuable for industrial production.Physical properties test indicates that the new compounds have virtual clearing point of 127.7℃ and a large splay elastic constant K11 value of 19.7. Transmittance-voltage test shows that the compound can shorten the total response time by 10%,which coincides with its low elastic-viscosity value. The new 3-butenyl-based liquid crystals have potential applications in developing high performance liquid crystal mixtures.
3-Butenyl-based liquid crystals are a new series of liquid crystals with low melting point and high clearing point. A new synthetic method for key intermediate aryl boric acid was improved via Arbuzov,WittigHorner,catalytic hydrogenation and lithiation-boric acid 4-step reactions by using 3-fluorobenzyl chloride as the starting material. Isomerization of trans-cyclohexane and defluorination side reactions were avoided. After optimization the total yield was improved from 4.5% to 30%,which is valuable for industrial production.Physical properties test indicates that the new compounds have virtual clearing point of 127.7℃ and a large splay elastic constant K11 value of 19.7. Transmittance-voltage test shows that the compound can shorten the total response time by 10%,which coincides with its low elastic-viscosity value. The new 3-butenyl-based liquid crystals have potential applications in developing high performance liquid crystal mixtures.
2015, 32(3): 261-266
doi: 10.11944/j.issn.1000-0518.2015.03.140108
Abstract:
Isopropyl chloroformate and hydrazine were used as starting materials to prepare diisopropyl hydrazine-1,2-dicarboxylate,and then diisopropyl azodicarboxylate(DIAD) was prepared by oxidization with hydrogen peroxide. Factors influencing the reaction were investigated. Diisopropyl hydrazine-1,2-dicarboxylate was prepared by the reaction of hydrazine and chloroformate below 0℃ for 2 h in ether; under optimal reaction condition of n(diisopropyl hydrazine-1,2-dicarboxylate):n(hydrogen peroxide) with 1:1.1 at -5~5℃ for 2 h,the total yield of DIAD reached 90.7%. The structures of intermediate and product were characterized by IR and 1H NMR.
Isopropyl chloroformate and hydrazine were used as starting materials to prepare diisopropyl hydrazine-1,2-dicarboxylate,and then diisopropyl azodicarboxylate(DIAD) was prepared by oxidization with hydrogen peroxide. Factors influencing the reaction were investigated. Diisopropyl hydrazine-1,2-dicarboxylate was prepared by the reaction of hydrazine and chloroformate below 0℃ for 2 h in ether; under optimal reaction condition of n(diisopropyl hydrazine-1,2-dicarboxylate):n(hydrogen peroxide) with 1:1.1 at -5~5℃ for 2 h,the total yield of DIAD reached 90.7%. The structures of intermediate and product were characterized by IR and 1H NMR.
2015, 32(3): 267-272
doi: 10.11944/j.issn.1000-0518.2015.03.140250
Abstract:
By using o-aminophenyl methanol as the starting material and undergoing a dehydrogenation reaction,[RuCl2(p-cymene)]2/AgOTf was finally employed as the co-catalyst system upon a systematical screening of catalysts,which enables the dehydrogenation of o-aminophenyl methanol to undergo a crosscoupling reaction with terminal aryl alkynes,affording a series of 2-aryl quinolines in 39% to 47% yields. The study has demonstrated a new method for the synthesis of quinolines from o-aminophenyl methanol and terminal aryl alkynes,which is an important complement to the synthesis of quinoline derivatives.
By using o-aminophenyl methanol as the starting material and undergoing a dehydrogenation reaction,[RuCl2(p-cymene)]2/AgOTf was finally employed as the co-catalyst system upon a systematical screening of catalysts,which enables the dehydrogenation of o-aminophenyl methanol to undergo a crosscoupling reaction with terminal aryl alkynes,affording a series of 2-aryl quinolines in 39% to 47% yields. The study has demonstrated a new method for the synthesis of quinolines from o-aminophenyl methanol and terminal aryl alkynes,which is an important complement to the synthesis of quinoline derivatives.
2015, 32(3): 273-277
doi: 10.11944/j.issn.1000-0518.2015.03.140202
Abstract:
Using stigmasterol as a starting material,3β-acetoxycholest-5-ene-22-al was obtained by the protection of 3-hydroxyl and 5-double bond prior to the ozonolysis of 22-ene. Some 22-abeo-stigmast-22-nitrogen-containing compounds were synthesized by the condensation of aldehydes with semicarbazides and thiosemicarbazides. The structure of compounds were confirmed with NMR,IR and MS. Their antiproliferative activities against six kinds of cancer cells were evaluated with MTT method. Compound 8 with the 22-thiosemicarbazone group exhibits significant inhibitory activity on MGC 7901,Hela,SMMC 7404 and CNE-2cells with the IC50 values of 10.5,11.6,8.7 and 11.9 μ mol/L,respectively.
Using stigmasterol as a starting material,3β-acetoxycholest-5-ene-22-al was obtained by the protection of 3-hydroxyl and 5-double bond prior to the ozonolysis of 22-ene. Some 22-abeo-stigmast-22-nitrogen-containing compounds were synthesized by the condensation of aldehydes with semicarbazides and thiosemicarbazides. The structure of compounds were confirmed with NMR,IR and MS. Their antiproliferative activities against six kinds of cancer cells were evaluated with MTT method. Compound 8 with the 22-thiosemicarbazone group exhibits significant inhibitory activity on MGC 7901,Hela,SMMC 7404 and CNE-2cells with the IC50 values of 10.5,11.6,8.7 and 11.9 μ mol/L,respectively.
2015, 32(3): 278-283
doi: 10.11944/j.issn.1000-0518.2015.03.140197
Abstract:
Ten 5-[(indol-3-yl)-methyl]-2,2-dimethyl-1,3-dioxane-4,6-dione derivatives were synthesized by the three component condensation reaction of indole,aldehyde and 2,2-dimethyl-1,3-dioxane-4,6-dione using iodine as the catalyst. The results indicates that the yields range from 71.4% to 97.3% at 30℃ for 60~90 min using 5% molar fraction of iodine. Furthermore,a mechanism for the reaction catalyzed by iodine is proposed.
Ten 5-[(indol-3-yl)-methyl]-2,2-dimethyl-1,3-dioxane-4,6-dione derivatives were synthesized by the three component condensation reaction of indole,aldehyde and 2,2-dimethyl-1,3-dioxane-4,6-dione using iodine as the catalyst. The results indicates that the yields range from 71.4% to 97.3% at 30℃ for 60~90 min using 5% molar fraction of iodine. Furthermore,a mechanism for the reaction catalyzed by iodine is proposed.
2015, 32(3): 284-291
doi: 10.11944/j.issn.1000-0518.2015.03.140247
Abstract:
The [1+1] Schiff base macrocyclic compound 3 was synthesized via the condensation of precursor 1[1,3-bis(2'-formylphenoxy) propane] and precursor 2[N,N'-(2-aminophenyl) pyridine-2,6-dicarboxamide] in the presence of sulfuric acid. Macrocycle 3 was reduced to the corresponding saturated macrocycle 4. Their structures were characterized by 1H NMR,IR,MS spectra and elemental analysis. The crystal structures of the two macrocycles were determined by the X-ray diffraction analysis. The study of the reaction of the macrocyclic compound 3 or 4 with a series of anions was performed by UV-Vis absorption spectra technique. The results show that the saturated macrocycle 4 displayed a selective recognition for Fion,and the stoichiometric ratio and the stability constant of the complex were determined. Furthermore the adsorption abilities of the two macrocycles for methanol were investigated.
The [1+1] Schiff base macrocyclic compound 3 was synthesized via the condensation of precursor 1[1,3-bis(2'-formylphenoxy) propane] and precursor 2[N,N'-(2-aminophenyl) pyridine-2,6-dicarboxamide] in the presence of sulfuric acid. Macrocycle 3 was reduced to the corresponding saturated macrocycle 4. Their structures were characterized by 1H NMR,IR,MS spectra and elemental analysis. The crystal structures of the two macrocycles were determined by the X-ray diffraction analysis. The study of the reaction of the macrocyclic compound 3 or 4 with a series of anions was performed by UV-Vis absorption spectra technique. The results show that the saturated macrocycle 4 displayed a selective recognition for Fion,and the stoichiometric ratio and the stability constant of the complex were determined. Furthermore the adsorption abilities of the two macrocycles for methanol were investigated.
2015, 32(3): 292-298
doi: 10.11944/j.issn.1000-0518.2015.03.140231
Abstract:
A series of aromatic oligosulfonate-bridged macrocyclic compounds was synthesized using aromatic disulfonyl chlorides and aromatic diphenol as the starting materials. The products were characterized by IR,1H NMR,13C NMR and MALDI-TOF-MS. The synthetic methods,UV spectra and variable-temperature 1H NMR experiments were also discussed herein. UV spectra maximum absorption peaks of compounds 3~5 and compound 6 in DMF solutions are at 266 nm and 267 nm,respectively. The molar absorption coefficients are 4.65×104,5.61×104,5.09×104 and 9.98×104 L/( mol·cm),respectively. The detection limits are2.15×10-7,1.78×10-7,1.96×10-7and 1.00×10-7 mol/L,respectively. Variable-temperature 1H NMR experiments show that branched benzene rings can lock the conformation and facilitate the synthesis of desired macrocylces.
A series of aromatic oligosulfonate-bridged macrocyclic compounds was synthesized using aromatic disulfonyl chlorides and aromatic diphenol as the starting materials. The products were characterized by IR,1H NMR,13C NMR and MALDI-TOF-MS. The synthetic methods,UV spectra and variable-temperature 1H NMR experiments were also discussed herein. UV spectra maximum absorption peaks of compounds 3~5 and compound 6 in DMF solutions are at 266 nm and 267 nm,respectively. The molar absorption coefficients are 4.65×104,5.61×104,5.09×104 and 9.98×104 L/( mol·cm),respectively. The detection limits are2.15×10-7,1.78×10-7,1.96×10-7and 1.00×10-7 mol/L,respectively. Variable-temperature 1H NMR experiments show that branched benzene rings can lock the conformation and facilitate the synthesis of desired macrocylces.
2015, 32(3): 299-303
doi: 10.11944/j.issn.1000-0518.2015.03.140212
Abstract:
Penta-coordinated anionic organotin carboxylate compounds were synthesized by the reaction of Ph3SnCl with HOOCC6H4COOH in the presence of organic amines. The products were characterized by elemental analysis,IR,and 1H NMR spectroscopy. These compounds show good bactericidal activities for 10 bacteria. The mortality rates of the products are 100% for Phomopsis asparagi,Cercospora arachidicola Hoci,Ustilaginoidea virens and Cladosporium cucumerinum,and moderate for the orther bacteria.
Penta-coordinated anionic organotin carboxylate compounds were synthesized by the reaction of Ph3SnCl with HOOCC6H4COOH in the presence of organic amines. The products were characterized by elemental analysis,IR,and 1H NMR spectroscopy. These compounds show good bactericidal activities for 10 bacteria. The mortality rates of the products are 100% for Phomopsis asparagi,Cercospora arachidicola Hoci,Ustilaginoidea virens and Cladosporium cucumerinum,and moderate for the orther bacteria.
2015, 32(3): 304-309
doi: 10.11944/j.issn.1000-0518.2015.03.140228
Abstract:
A novel modified active carbon supported ferric chloride catalyst(MAC-FeCl3) has been prepared and characterized by IR and ICP-AES. In the presence of MAC-FeCl3,condensation of aldehydes andβ-naphthol was carried out in PEG 200 to afford a series of xanthene derivatives in 79%~93% yields within 60~120 min. The prepared catalyst can be recycled easily and the activity of catalyst maintains stable after used for 4 times. This affords this methodology the advantages on good yields,less pollution and simple workup.
A novel modified active carbon supported ferric chloride catalyst(MAC-FeCl3) has been prepared and characterized by IR and ICP-AES. In the presence of MAC-FeCl3,condensation of aldehydes andβ-naphthol was carried out in PEG 200 to afford a series of xanthene derivatives in 79%~93% yields within 60~120 min. The prepared catalyst can be recycled easily and the activity of catalyst maintains stable after used for 4 times. This affords this methodology the advantages on good yields,less pollution and simple workup.
2015, 32(3): 310-316
doi: 10.11944/j.issn.1000-0518.2015.03.140204
Abstract:
Pd/polyelectrolyte hollow nanospheres were prepared by a facile method that combined the surfaceinitiated atom transfer radical polymerization(SI-ATRP) and in situ growth of metal nanoparticles.Transmission electron microscopy(TEM),Fourier transform infrared spectra(FTIR),energy-dispersive X-ray(EDX) and thermogravimetric analysis(TGA) were used to characterize the morphology and structure of air@PMETAI@Pd(PMETAI:poly{[2-(methacryloyloxy) ethyl] trimethylammonium iodide}) nanospheres.The result shows that Pd nanoparticles with diameter of(1.5±0.2) nm are homogeneously embedded inside the polyelectrolyte layer. Catalytic activity of the Pd/polyelectrolyte hollow nanospheres was investigated by the reduction of 4-nitrophenol with NaBH4 as a model reaction. It is found that they displayed excellent catalytic properties and good reusability.
Pd/polyelectrolyte hollow nanospheres were prepared by a facile method that combined the surfaceinitiated atom transfer radical polymerization(SI-ATRP) and in situ growth of metal nanoparticles.Transmission electron microscopy(TEM),Fourier transform infrared spectra(FTIR),energy-dispersive X-ray(EDX) and thermogravimetric analysis(TGA) were used to characterize the morphology and structure of air@PMETAI@Pd(PMETAI:poly{[2-(methacryloyloxy) ethyl] trimethylammonium iodide}) nanospheres.The result shows that Pd nanoparticles with diameter of(1.5±0.2) nm are homogeneously embedded inside the polyelectrolyte layer. Catalytic activity of the Pd/polyelectrolyte hollow nanospheres was investigated by the reduction of 4-nitrophenol with NaBH4 as a model reaction. It is found that they displayed excellent catalytic properties and good reusability.
2015, 32(3): 317-321
doi: 10.11944/j.issn.1000-0518.2015.03.140234
Abstract:
Oxidation catalysts of organic sulfide were synthesized by the ferromagnetic Fe3O4 matrix and phosphotungstic acid urea complexes(PAUC). The properties of products were characterized by IR,XRD,Raman and TG. With introduction of oxidation catalysts of organic sulfide,it is found that PAUC exists on Fe3O4 support in a Keggin structure and there is a chemical bond effect between them. If the H2O2 oxidation of ethanethiol proceeds in n-hexane,the oxidation activity of ethanethiol over ferromagnetic Fe3O4 matrix is increased in the presence of the PAUC. The effect of urea on activity has been discussed.
Oxidation catalysts of organic sulfide were synthesized by the ferromagnetic Fe3O4 matrix and phosphotungstic acid urea complexes(PAUC). The properties of products were characterized by IR,XRD,Raman and TG. With introduction of oxidation catalysts of organic sulfide,it is found that PAUC exists on Fe3O4 support in a Keggin structure and there is a chemical bond effect between them. If the H2O2 oxidation of ethanethiol proceeds in n-hexane,the oxidation activity of ethanethiol over ferromagnetic Fe3O4 matrix is increased in the presence of the PAUC. The effect of urea on activity has been discussed.
Preparation and Antioxidant Activity of Novel Double Quaternary Ammonium Salt Derivative of Chitosan
2015, 32(3): 322-326
doi: 10.11944/j.issn.1000-0518.2015.03.140209
Abstract:
Water soluble chitosan quaternary ammonium salt derivative(HTCC) was prepared via reaction of chitosan and 2,3-epoxy propyl trimethyl ammonium chloride(CAT) firstly. Secondly,CAHTCC was obtained by reaction of chloroacetyl chloride and HTCC. Finally,double quaternary ammonium salt derivative of chitosan(PAHTCC) was synthesized by reaction of pyridine and CAHTCC. The structure of HTCC,CAHTCC and PAHTCC were characterized by FT-IR and 13C NMR. The HO·,·O2-,·DPPH scavenging activities of the derivatives were tested. The results show that,the antioxidant activity of PAHTCC is enhanced comparing with chitosan,HTCC and CAHTCC. The HO·,·O2-,·DPPH scavenging rate of PAHTCC is 68.5%,74.3%and 80.8% at 1.6 g/L,respectively. The reason may be attributed to the double quaternary ammonium salt structure in PAHTCC molecule.
Water soluble chitosan quaternary ammonium salt derivative(HTCC) was prepared via reaction of chitosan and 2,3-epoxy propyl trimethyl ammonium chloride(CAT) firstly. Secondly,CAHTCC was obtained by reaction of chloroacetyl chloride and HTCC. Finally,double quaternary ammonium salt derivative of chitosan(PAHTCC) was synthesized by reaction of pyridine and CAHTCC. The structure of HTCC,CAHTCC and PAHTCC were characterized by FT-IR and 13C NMR. The HO·,·O2-,·DPPH scavenging activities of the derivatives were tested. The results show that,the antioxidant activity of PAHTCC is enhanced comparing with chitosan,HTCC and CAHTCC. The HO·,·O2-,·DPPH scavenging rate of PAHTCC is 68.5%,74.3%and 80.8% at 1.6 g/L,respectively. The reason may be attributed to the double quaternary ammonium salt structure in PAHTCC molecule.
2015, 32(3): 327-334
doi: 10.11944/j.issn.1000-0518.2015.03.140240
Abstract:
Electrostatic interactions between proteins and polysaccharides are a fundamental physico-chemical phenomenon in vivo. These interactions are believed to be the main driving force for the self-assembly. In addition,a proper understanding and control of this interaction should enable to design desired structures.Herein,the influences of mass ratios of chitosan(CS) to soybean protein isolates(SPI),pH,ion strength and temperature on the interactions between SPI and CS were investigated. The strength of electrostatic interactions between SPI and CS were mainly influenced by the pH values of solutions. The aggregation of SPI and CS occurred at pH varying from 5.5 to 6.6. At the low ion strength,a compact CS/SPI aggregates was formed,whereas,CS/SPI aggregates are dissociated at higher ion strength. As the heating induced denaturation of SPI,hydrophobic amino acid residues on the peptide chains are exposed to the solution,which results in an increase in hydrophobic interactions between CS and SPI. Furthermore,CS/SPI particles and bilayer film were prepared by adjusting the factors above. DLS reveals that nanoparticles are formed by the self-assembly between CS and SPI,and the hydrodynamic diameter is about 200 nm with uniform distribution. After the denaturation of SPI induced by heating, the hydrodynamic diameter is increased. Cross-linking by glutaraldehyde inducs a little decrease of hydrodynamic diameter. SEM results show that there are some cracks in the surface of chitosan monolayer film with thickness of ca 300 nm,and the cracks disappear after the formation of the bilayer film(CS/SPI) with thickness of ca 500 nm.
Electrostatic interactions between proteins and polysaccharides are a fundamental physico-chemical phenomenon in vivo. These interactions are believed to be the main driving force for the self-assembly. In addition,a proper understanding and control of this interaction should enable to design desired structures.Herein,the influences of mass ratios of chitosan(CS) to soybean protein isolates(SPI),pH,ion strength and temperature on the interactions between SPI and CS were investigated. The strength of electrostatic interactions between SPI and CS were mainly influenced by the pH values of solutions. The aggregation of SPI and CS occurred at pH varying from 5.5 to 6.6. At the low ion strength,a compact CS/SPI aggregates was formed,whereas,CS/SPI aggregates are dissociated at higher ion strength. As the heating induced denaturation of SPI,hydrophobic amino acid residues on the peptide chains are exposed to the solution,which results in an increase in hydrophobic interactions between CS and SPI. Furthermore,CS/SPI particles and bilayer film were prepared by adjusting the factors above. DLS reveals that nanoparticles are formed by the self-assembly between CS and SPI,and the hydrodynamic diameter is about 200 nm with uniform distribution. After the denaturation of SPI induced by heating, the hydrodynamic diameter is increased. Cross-linking by glutaraldehyde inducs a little decrease of hydrodynamic diameter. SEM results show that there are some cracks in the surface of chitosan monolayer film with thickness of ca 300 nm,and the cracks disappear after the formation of the bilayer film(CS/SPI) with thickness of ca 500 nm.
2015, 32(3): 335-341
doi: 10.11944/j.issn.1000-0518.2015.03.140239
Abstract:
A new two-dimensional Co(Ⅱ) coordination polymer {[Co(bppdca)(L)]3H2O}n[bppdca=N,N'-bis(pyridine-3-yl) pyridine-3,5-dicarboxamide,L=2-carboxymethylsulfanyl nicotinic acid] has been hydrothermally synthesized and structurally characterized by elementary analysis,IR and single crystal X-ray diffraction analysis.[Co(bppdca)(L)]·3H2O is monoclinic with a space group of P1/c,a=1.07419(9) nm,b=0.86166(6) nm,c=2.9853(2) nm,β=96.772(1) °,Z=4,V=2.7439(4) nm3,Mr=643.49,Dc=1.558 g/cm3,F(000)=1324,μ=0.766 mm-1,S=1.051,the final R=0.0406 and wR=0.1160. The crystal structure analysis indicates that the Co(Ⅱ) cation is six-coordinated by two nitrogen atoms from two bppdca ligands,one monodentate O atom and one S atom from one L anion,two chelating O atoms from another L anion. The adjacent Co(Ⅱ) ions are linked by L anions to form one-dimensional helical chain[Co(L)]n and the chains are further connected by pairs of bppdca ligands to generate a two-dimensional network. Finally,the networks are linked by hydrogen bonding to form a three-dimensional supra molecular framework. Moreover, the thermal stability, electrochemical property, photoluminescence property and selective photocatalytic activity of the title compound are investigated.
A new two-dimensional Co(Ⅱ) coordination polymer {[Co(bppdca)(L)]3H2O}n[bppdca=N,N'-bis(pyridine-3-yl) pyridine-3,5-dicarboxamide,L=2-carboxymethylsulfanyl nicotinic acid] has been hydrothermally synthesized and structurally characterized by elementary analysis,IR and single crystal X-ray diffraction analysis.[Co(bppdca)(L)]·3H2O is monoclinic with a space group of P1/c,a=1.07419(9) nm,b=0.86166(6) nm,c=2.9853(2) nm,β=96.772(1) °,Z=4,V=2.7439(4) nm3,Mr=643.49,Dc=1.558 g/cm3,F(000)=1324,μ=0.766 mm-1,S=1.051,the final R=0.0406 and wR=0.1160. The crystal structure analysis indicates that the Co(Ⅱ) cation is six-coordinated by two nitrogen atoms from two bppdca ligands,one monodentate O atom and one S atom from one L anion,two chelating O atoms from another L anion. The adjacent Co(Ⅱ) ions are linked by L anions to form one-dimensional helical chain[Co(L)]n and the chains are further connected by pairs of bppdca ligands to generate a two-dimensional network. Finally,the networks are linked by hydrogen bonding to form a three-dimensional supra molecular framework. Moreover, the thermal stability, electrochemical property, photoluminescence property and selective photocatalytic activity of the title compound are investigated.
2015, 32(3): 342-349
doi: 10.11944/j.issn.1000-0518.2015.03.140227
Abstract:
The properties and performances of four kinds of quaternary ammonium salt monomers were researched. The relationships between structures and properties or performances for the four kinds of diallylmethylalkyl(n=12,14,16,18) ammonium bromides(marked C12,C14,C16,C18) were discussed on the basis of the determination of the thermal stability, surfactivity and flocculation ability. Quaternary ammonium salts C12~C18 decompose within 170~300℃,172~303℃,170~293℃ and 170~310℃,their mass loss rates are 92.8%, 92.6%, 96.4% and 87.4%, respectively. Their critical micelle concentration(cmc) and the corresponding surface tension(γcmc) are 2.0,3.5,1.4,1.1 mmol/L and 26.6,25.2,33.8,35.8 m N/m,respectively. All monomers show excellent surfactivity. The quaternary ammonium salt C16 possesses the best foaming power and foam stability. C12 Krafft point is <0℃. Krafft points of C14,C16 and C18 are 1℃,8℃ and 19℃,respectively. The C12 and C14 appear the strongest flocculation ability to bentonite and kaolin suspansion,indicating that the flocculation performance of monomers are of certain selectivity to structures.
The properties and performances of four kinds of quaternary ammonium salt monomers were researched. The relationships between structures and properties or performances for the four kinds of diallylmethylalkyl(n=12,14,16,18) ammonium bromides(marked C12,C14,C16,C18) were discussed on the basis of the determination of the thermal stability, surfactivity and flocculation ability. Quaternary ammonium salts C12~C18 decompose within 170~300℃,172~303℃,170~293℃ and 170~310℃,their mass loss rates are 92.8%, 92.6%, 96.4% and 87.4%, respectively. Their critical micelle concentration(cmc) and the corresponding surface tension(γcmc) are 2.0,3.5,1.4,1.1 mmol/L and 26.6,25.2,33.8,35.8 m N/m,respectively. All monomers show excellent surfactivity. The quaternary ammonium salt C16 possesses the best foaming power and foam stability. C12 Krafft point is <0℃. Krafft points of C14,C16 and C18 are 1℃,8℃ and 19℃,respectively. The C12 and C14 appear the strongest flocculation ability to bentonite and kaolin suspansion,indicating that the flocculation performance of monomers are of certain selectivity to structures.
2015, 32(3): 350-355
doi: 10.11944/j.issn.1000-0518.2015.03.140159
Abstract:
Double perovskite LaPbMnSbO6 was synthesized by two-step semi-chemical method,and the crystal structure and magnetic properties have been investigated. The crystal structure has been solved by X-ray diffraction(XRD) data in the monoclinic space group P1/n(No. 14). The Mn6 and SbO6 octahedra are rock-salt ordered over the B-site of the perovskite structure. Due to the existence of Pb2+ ions,secondorder Jahn-Teller effect is occurred and the lattice distortions are anisotropic in the interior of BO6 octahedra.The magnetization curves show a typical antiferromagnetic ordering, with an antiferromagnetic ordering transition temperature at TN=9 K.
Double perovskite LaPbMnSbO6 was synthesized by two-step semi-chemical method,and the crystal structure and magnetic properties have been investigated. The crystal structure has been solved by X-ray diffraction(XRD) data in the monoclinic space group P1/n(No. 14). The Mn6 and SbO6 octahedra are rock-salt ordered over the B-site of the perovskite structure. Due to the existence of Pb2+ ions,secondorder Jahn-Teller effect is occurred and the lattice distortions are anisotropic in the interior of BO6 octahedra.The magnetization curves show a typical antiferromagnetic ordering, with an antiferromagnetic ordering transition temperature at TN=9 K.
2015, 32(3): 356-361
doi: 10.11944/j.issn.1000-0518.2015.03.140196
Abstract:
A simple simultaneous distillation and solvent extraction(SSDE) method was developed and had been applied for sample preparation of the gas chromatography-mass spectrometry(GC-MS) analysis of volatile components from Illicium Verum. The simple apparatus was composed of a round flask,a constant pressure dropping funnel and a condenser. The constituents of the volatile oil obtained by SSDE were compared with those obtained by hydrodistillation method(HD) followed by GC-MS analysis. In terms of GC-MS analysis of volatile oil,the relative standard deviation(RSD) values(n=3) of measured relative contents(>0.1%) of19 identified compounds are no more than 5.59%. The total content of above components is 98.84% of the volatile oil,in which there are 17 components in 89.5% content with RSD less than 5%. And the yield of volatile oil obtained by SSDE and HD is 7.30%(RSD 2.37%(n=5)) and 6.67%(RSD 5.26%(n=5)),respectively. These results indicate that SSDE is a simple,suitable method for the extraction of volatile oil from Illicium Verum.
A simple simultaneous distillation and solvent extraction(SSDE) method was developed and had been applied for sample preparation of the gas chromatography-mass spectrometry(GC-MS) analysis of volatile components from Illicium Verum. The simple apparatus was composed of a round flask,a constant pressure dropping funnel and a condenser. The constituents of the volatile oil obtained by SSDE were compared with those obtained by hydrodistillation method(HD) followed by GC-MS analysis. In terms of GC-MS analysis of volatile oil,the relative standard deviation(RSD) values(n=3) of measured relative contents(>0.1%) of19 identified compounds are no more than 5.59%. The total content of above components is 98.84% of the volatile oil,in which there are 17 components in 89.5% content with RSD less than 5%. And the yield of volatile oil obtained by SSDE and HD is 7.30%(RSD 2.37%(n=5)) and 6.67%(RSD 5.26%(n=5)),respectively. These results indicate that SSDE is a simple,suitable method for the extraction of volatile oil from Illicium Verum.
2015, 32(3): 362-366
doi: 10.11944/j.issn.1000-0518.2015.03.140437
Abstract:
An aptamer-based microcantilever biosensor for label-free detection of adenosine triphosphate(ATP) was developed. The sensor cantilevers in the microcantilever array were functionalized with ATP aptamer on the gold side to recognize ATP,while the reference cantilevers were modified by 6-mercapto-1-hexanol(MCH) to prevent non-specific absorption. The interaction between ATP and aptamer on the sensor cantilerers gold surface induced surface stress changes,resulting in a differential deflection between the sensor and reference cantilevers. The differential deflection has a good linear relationship with the ATP concentration ranging from 0.5~5 mmol/L with a correlation coefficient of 0.998. The detection limit is about 0.06 mmol/L.The aptamer-based microcantilever sensor shows rapid response,simple procedures and high specificity for ATP.
An aptamer-based microcantilever biosensor for label-free detection of adenosine triphosphate(ATP) was developed. The sensor cantilevers in the microcantilever array were functionalized with ATP aptamer on the gold side to recognize ATP,while the reference cantilevers were modified by 6-mercapto-1-hexanol(MCH) to prevent non-specific absorption. The interaction between ATP and aptamer on the sensor cantilerers gold surface induced surface stress changes,resulting in a differential deflection between the sensor and reference cantilevers. The differential deflection has a good linear relationship with the ATP concentration ranging from 0.5~5 mmol/L with a correlation coefficient of 0.998. The detection limit is about 0.06 mmol/L.The aptamer-based microcantilever sensor shows rapid response,simple procedures and high specificity for ATP.
