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2005 Volume 16 Issue 2
2005, 16(2): 143-146
Abstract:
Diacetyl derivative of hecogenin 1 was oxidized to unsaturated ketone 5 via allylic alcohol 3 when it reacted with dimethyldioxirane (DMDO). The structure of 3 was confimed by X-ray crystal analysis and the highly regioselectivity of DMDO to different olefin bonds was also observed when diosgenin derivative 6 was treated with DMDO.
Diacetyl derivative of hecogenin 1 was oxidized to unsaturated ketone 5 via allylic alcohol 3 when it reacted with dimethyldioxirane (DMDO). The structure of 3 was confimed by X-ray crystal analysis and the highly regioselectivity of DMDO to different olefin bonds was also observed when diosgenin derivative 6 was treated with DMDO.
2005, 16(2): 147-150
Abstract:
A series of tyrosinase model ligands and complexes containing polyimidazoles were prepared. 2, 4-Di-tert-butyl-phenol was ortho-hydroxylated by the binuclear copper (I) complex [Cu2 (6a) (CH3CN)2] (ClO4)2 8a and molecular dioxygen under mild conditions with up to 80.4% yield, 91.4% selectivity and 92.0% conversion.
A series of tyrosinase model ligands and complexes containing polyimidazoles were prepared. 2, 4-Di-tert-butyl-phenol was ortho-hydroxylated by the binuclear copper (I) complex [Cu2 (6a) (CH3CN)2] (ClO4)2 8a and molecular dioxygen under mild conditions with up to 80.4% yield, 91.4% selectivity and 92.0% conversion.
2005, 16(2): 151-154
Abstract:
S-akyl thiobenzoate compounds were designed as famesyltransferase (FTase) inhibitors.An effective synthetic method was explored. The structures of the target compounds were elucidated by NMR spectral and elemental analysis.
S-akyl thiobenzoate compounds were designed as famesyltransferase (FTase) inhibitors.An effective synthetic method was explored. The structures of the target compounds were elucidated by NMR spectral and elemental analysis.
2005, 16(2): 155-158
Abstract:
1-(α-Alkoxyalkyl) benzotriazoles are readily synthesized from three-component condensation of benzotriazole with aldehyde and alcohol in ionic liquid [Bmim]PF6.
1-(α-Alkoxyalkyl) benzotriazoles are readily synthesized from three-component condensation of benzotriazole with aldehyde and alcohol in ionic liquid [Bmim]PF6.
2005, 16(2): 159-162
Abstract:
A novel triphenylamine derivative of 4, 4'-bis-[2-[4-[N, N-bis-(4-methoxyphenyl-amino)] phenyl-1-yl]-vinyl-1-yl]-1, 1'-biphenyl (DMPAVBI) was synthesized. The chemical structure was confirmed by IR, 1H NMR spectroscopy and elemental analysis. Its properties were studied by UV-Vis spectroscopy, photoluminescence spectroscopy and cyclic voltammetry methods.
A novel triphenylamine derivative of 4, 4'-bis-[2-[4-[N, N-bis-(4-methoxyphenyl-amino)] phenyl-1-yl]-vinyl-1-yl]-1, 1'-biphenyl (DMPAVBI) was synthesized. The chemical structure was confirmed by IR, 1H NMR spectroscopy and elemental analysis. Its properties were studied by UV-Vis spectroscopy, photoluminescence spectroscopy and cyclic voltammetry methods.
2005, 16(2): 163-166
Abstract:
Based on the structure of FK506, FKBP12 and calcineurin complex and the interactive characteristics of small molecular ligands with FKBPs, a series of L-1,4-thiazane-3-carboxylic acid derivatives as neuroimmunophilin ligands was designed and synthesized. The results of evaluation show that compound N308 has a great promise as a candidate of neuroprotective and neuroregenerative agent.
Based on the structure of FK506, FKBP12 and calcineurin complex and the interactive characteristics of small molecular ligands with FKBPs, a series of L-1,4-thiazane-3-carboxylic acid derivatives as neuroimmunophilin ligands was designed and synthesized. The results of evaluation show that compound N308 has a great promise as a candidate of neuroprotective and neuroregenerative agent.
2005, 16(2): 167-170
Abstract:
(S)-Dimethyl-4, 4'-dimethoxy-5, 6, 5', 6'-dimethenedioxy-biphenyl-2, 2'-dicarbonylate was synthesized in reasonable yield through a series of reactions, including chiral oxazoline-mediated asymmetric Ullmann coupling, from methyl 2-bromo-5-methoxy-3, 4-methenedioxy-benzoate.
(S)-Dimethyl-4, 4'-dimethoxy-5, 6, 5', 6'-dimethenedioxy-biphenyl-2, 2'-dicarbonylate was synthesized in reasonable yield through a series of reactions, including chiral oxazoline-mediated asymmetric Ullmann coupling, from methyl 2-bromo-5-methoxy-3, 4-methenedioxy-benzoate.
2005, 16(2): 171-174
Abstract:
Highly efficient synthesis of the entitled compound was achieved from a readily available myo-inositol derivative. The key step involved a desymmetrization with (+)-camphor dimethyl ketal to give two diastereomers. The two diastereomers could be used to synthesize the same compound by changing the orders to introduce the protective groups.
Highly efficient synthesis of the entitled compound was achieved from a readily available myo-inositol derivative. The key step involved a desymmetrization with (+)-camphor dimethyl ketal to give two diastereomers. The two diastereomers could be used to synthesize the same compound by changing the orders to introduce the protective groups.
2005, 16(2): 175-178
Abstract:
Novel diarylethene derivatives:N-substituted-3,4-bisheteroaryl-2,5-dihydropyrroles were synthesized through Mcmurry couple reaction with high yields. The photochromic properties and UV-Vis absorption spectra were studied. The maximal absorptions of their close forms were around at 406 nm or 446 nm, which related mainly with heteroaryl groups but not with substituted groups at nitrogen atom of dihydropyrrole. The absorption of their colored form could be matched with blue light laser.
Novel diarylethene derivatives:N-substituted-3,4-bisheteroaryl-2,5-dihydropyrroles were synthesized through Mcmurry couple reaction with high yields. The photochromic properties and UV-Vis absorption spectra were studied. The maximal absorptions of their close forms were around at 406 nm or 446 nm, which related mainly with heteroaryl groups but not with substituted groups at nitrogen atom of dihydropyrrole. The absorption of their colored form could be matched with blue light laser.
2005, 16(2): 179-182
Abstract:
Two series of indomethacin conjugates with D-glucosamine were prepared with the objectives of reducing ulcerogenic potency, increasing the bioavailability of indomethacin and exerting the coordinative effects on osteoarthritis. The structures of the conjugates were identified by 1H NMR and 13C NMR. The ester conjugates inhibited edema as potent as indomethacin.
Two series of indomethacin conjugates with D-glucosamine were prepared with the objectives of reducing ulcerogenic potency, increasing the bioavailability of indomethacin and exerting the coordinative effects on osteoarthritis. The structures of the conjugates were identified by 1H NMR and 13C NMR. The ester conjugates inhibited edema as potent as indomethacin.
2005, 16(2): 183-185
Abstract:
Solid superacid, silica-supported polytrifluoromethanesulfosiloxane (SiO2-Si-SCF3) was firstly used in the Friedel-Crafts acylation of ferrocene as a novel catalyst. IR spectra, WAXD and specific surface area of the superacid SiO2-Si-SCF3 were also investigated.
Solid superacid, silica-supported polytrifluoromethanesulfosiloxane (SiO2-Si-SCF3) was firstly used in the Friedel-Crafts acylation of ferrocene as a novel catalyst. IR spectra, WAXD and specific surface area of the superacid SiO2-Si-SCF3 were also investigated.
2005, 16(2): 186-188
Abstract:
An asymmetric total synthesis of mansonone P and R were achieved, in which introduction of hydroxy substituent at position 2 was performed by Sharpless dihydroxylation of sily enol ether.
An asymmetric total synthesis of mansonone P and R were achieved, in which introduction of hydroxy substituent at position 2 was performed by Sharpless dihydroxylation of sily enol ether.
2005, 16(2): 189-192
Abstract:
2-Alkylamino-5, 6, 7, 8-tetrahydrobenzothieno [2, 3-d] pyrimidin-4 (3H)-ones 7 were synthesized by a new selective synthetic method, which includes aza-Wittig reaction of iminophosphorane 4 with aromatic isocynate to give carbodiimide 5 and subsequent reaction of 5 with various aliphatic primary amine in the presence of EtO-Na+.
2-Alkylamino-5, 6, 7, 8-tetrahydrobenzothieno [2, 3-d] pyrimidin-4 (3H)-ones 7 were synthesized by a new selective synthetic method, which includes aza-Wittig reaction of iminophosphorane 4 with aromatic isocynate to give carbodiimide 5 and subsequent reaction of 5 with various aliphatic primary amine in the presence of EtO-Na+.
2005, 16(2): 193-196
Abstract:
The title complexes, R'2Sn (3,5-Br2-2-OC6H2CH=NCHRCOO), and their diphenyltin dichloride adduct, R'2Sn(3,5-Br2-2-OC6H2CH=NCHRCOO)·SnPh2Cl2, were synthesized and char-acterized by elemental analysis, IR, 1H and 13C NMR and X-ray single crystal diffraction. The structural features of the compounds were described.
The title complexes, R'2Sn (3,5-Br2-2-OC6H2CH=NCHRCOO), and their diphenyltin dichloride adduct, R'2Sn(3,5-Br2-2-OC6H2CH=NCHRCOO)·SnPh2Cl2, were synthesized and char-acterized by elemental analysis, IR, 1H and 13C NMR and X-ray single crystal diffraction. The structural features of the compounds were described.
2005, 16(2): 197-200
Abstract:
2-Diethylaminoethyl aryloxyacetates are prepared efficiently in 75~95% yields by condensation of the corresponding aryloxyacetic acids with 2-diethylaminoethanol in the presence of catalytic amount of solid superacid SO42-/Fe2O3.
2-Diethylaminoethyl aryloxyacetates are prepared efficiently in 75~95% yields by condensation of the corresponding aryloxyacetic acids with 2-diethylaminoethanol in the presence of catalytic amount of solid superacid SO42-/Fe2O3.
2005, 16(2): 201-204
Abstract:
In ionic liquid [Bmim] [BF4], a series of disubstituted and trisubstituted thiourea derivatives were synthesized from phenyl and butyl isothiocyanate with a variety of amine in excellent yield.
In ionic liquid [Bmim] [BF4], a series of disubstituted and trisubstituted thiourea derivatives were synthesized from phenyl and butyl isothiocyanate with a variety of amine in excellent yield.
2005, 16(2): 205-208
Abstract:
Two novel analogues of triptolide were synthesized using triptolide as the starting material through reductive opening of epoxy ring, hydration and olefin epoxidation, and related ketones have also been afforded by oxidation of them with IBX or Jone's reagent.
Two novel analogues of triptolide were synthesized using triptolide as the starting material through reductive opening of epoxy ring, hydration and olefin epoxidation, and related ketones have also been afforded by oxidation of them with IBX or Jone's reagent.
2005, 16(2): 209-211
Abstract:
A new compound named 13b (S)-hydroxy-17c-ethoxypheaophorbide a (2) together with a known compound 17c-ethoxypheaophorbide a (1) were isolated from marine sponge Dysidea sp.collected in South China sea. The structures were elucidated by spectroscopic analysis as well as comparison with those reported in literatures.
A new compound named 13b (S)-hydroxy-17c-ethoxypheaophorbide a (2) together with a known compound 17c-ethoxypheaophorbide a (1) were isolated from marine sponge Dysidea sp.collected in South China sea. The structures were elucidated by spectroscopic analysis as well as comparison with those reported in literatures.
2005, 16(2): 212-214
Abstract:
Two new saponins named davuricoside I (1) and davuricoside E (2) were isolated from the whole plants of Lysimachia davurica. Their structures were determined by 1D and 2D NMR,FAB-MS techniques, and chemical methods.
Two new saponins named davuricoside I (1) and davuricoside E (2) were isolated from the whole plants of Lysimachia davurica. Their structures were determined by 1D and 2D NMR,FAB-MS techniques, and chemical methods.
2005, 16(2): 215-218
Abstract:
Pterocarine (1), a new diarylheptanoidal compound, was isolated from Pterocarya tonkinesis (Franch.) Dode. together with a known diarylheptanoid, myricatomentogenin (2), through a bioassay-guided fractionation procedure. The structure of 1 was elucidated as (+)-3', 4"-epoxy-1-(4'-hydroxyphenyl)-7-(3"-hydroxyphenyl)-heptane-3-one by the spectroscopic methods.Pterocarine (1) inhibited the proliferation of tsFT210, HCT-15 and K562 cells with the inhibition rates of 20.2±2.4, 23.8±2.4 and 50.5±1.2% at 100μg/mL, respectively. Flow cytometric analysis indicated that 1 could inhibit the cell cycle of tsFT210, HCT-15 and K562 cells at the G0/G1 phase and could also induce apoptosis in HCT-15 (19%) and K562 (11%) cells.
Pterocarine (1), a new diarylheptanoidal compound, was isolated from Pterocarya tonkinesis (Franch.) Dode. together with a known diarylheptanoid, myricatomentogenin (2), through a bioassay-guided fractionation procedure. The structure of 1 was elucidated as (+)-3', 4"-epoxy-1-(4'-hydroxyphenyl)-7-(3"-hydroxyphenyl)-heptane-3-one by the spectroscopic methods.Pterocarine (1) inhibited the proliferation of tsFT210, HCT-15 and K562 cells with the inhibition rates of 20.2±2.4, 23.8±2.4 and 50.5±1.2% at 100μg/mL, respectively. Flow cytometric analysis indicated that 1 could inhibit the cell cycle of tsFT210, HCT-15 and K562 cells at the G0/G1 phase and could also induce apoptosis in HCT-15 (19%) and K562 (11%) cells.
2005, 16(2): 219-222
Abstract:
New cyclic peptides 1 and 2 were isolated from the endophytic fungus #2221 from Castaniopsis fissa on the south China sea coast. By 2D NMR methods and chiral HPLC technique,their structures were elucidated as cyclo (L-Val-L-Leu-L-Val-L-Leu) and cyclo(L-Leu-L-Ala-L-Leu-L-Ala), respectively.
New cyclic peptides 1 and 2 were isolated from the endophytic fungus #2221 from Castaniopsis fissa on the south China sea coast. By 2D NMR methods and chiral HPLC technique,their structures were elucidated as cyclo (L-Val-L-Leu-L-Val-L-Leu) and cyclo(L-Leu-L-Ala-L-Leu-L-Ala), respectively.
2005, 16(2): 223-224
Abstract:
A novel oleanane-type triterpenic acid was isolated from the leaves of Gymnema sylvestre (Asclepiadaceae). The structure was characterized as 3β, 16β, 22β, 28-tetrahydroxy- olean-12-en-30-oic acid on the basis of spectral evidence, including 1D- and 2D-NMR (HMQC, HMBC, 1H-1H COSY and NOESY).
A novel oleanane-type triterpenic acid was isolated from the leaves of Gymnema sylvestre (Asclepiadaceae). The structure was characterized as 3β, 16β, 22β, 28-tetrahydroxy- olean-12-en-30-oic acid on the basis of spectral evidence, including 1D- and 2D-NMR (HMQC, HMBC, 1H-1H COSY and NOESY).
2005, 16(2): 225-228
Abstract:
A rapid method to determine glutamic acid (Glu) in cerebrospinal fluid (CSF) by capillary electrophoresis with high frequency conductivity detection (contactless conductivity detection) was described. The CSF sample was pretreated with silver cation resin to remove high concentration of Cl- ions in CSF. The separation was achieved in the buffer solution of 10 mmol/L Tris and 8 mmol/L boric acid at the separation voltage of 20.0 kV. Glu showed linear response in the range of 5.0×10-6 to 6.0×10-3 mol/L, the limit of detection was 1.0×10-6 mol/L. The method was used for analysis Glu in CSF satisfactorily with a recovery of 97.8-98.8%.
A rapid method to determine glutamic acid (Glu) in cerebrospinal fluid (CSF) by capillary electrophoresis with high frequency conductivity detection (contactless conductivity detection) was described. The CSF sample was pretreated with silver cation resin to remove high concentration of Cl- ions in CSF. The separation was achieved in the buffer solution of 10 mmol/L Tris and 8 mmol/L boric acid at the separation voltage of 20.0 kV. Glu showed linear response in the range of 5.0×10-6 to 6.0×10-3 mol/L, the limit of detection was 1.0×10-6 mol/L. The method was used for analysis Glu in CSF satisfactorily with a recovery of 97.8-98.8%.
2005, 16(2): 229-232
Abstract:
A novel multiwall carbon nanotube-chitosan modified electrode has been prepared.The modified electrode resolves the overlapping voltammetric response of dopamine and ascorbic acid into two well-defined peak by 212 mV. The mechanism of discrimination of dopamine from ascorbic acid is discussed. Dopamine can be determined selectively with the carbon nanotube-chitosan modified electrode. The electrode shows good sensitivity, selectivity and stability.
A novel multiwall carbon nanotube-chitosan modified electrode has been prepared.The modified electrode resolves the overlapping voltammetric response of dopamine and ascorbic acid into two well-defined peak by 212 mV. The mechanism of discrimination of dopamine from ascorbic acid is discussed. Dopamine can be determined selectively with the carbon nanotube-chitosan modified electrode. The electrode shows good sensitivity, selectivity and stability.
2005, 16(2): 233-236
Abstract:
Capillary column preparation using perpentylated (2,3,6-tri-O-pentyl)-β-cyclodextrin as stationary phase by sol-gel technology with simplicity and rapidity is described. Multiple preparation steps in conventional column technology were avoided. The prepared columns exhibit satisfactory chromatographic performances and pronounced selectivity for a wide range of test solutes, and have been successfully used for the separation of nitrotoluene, dimethoxybenzene,alcohols, alkanes, dimethylphenol and cresol isomers.
Capillary column preparation using perpentylated (2,3,6-tri-O-pentyl)-β-cyclodextrin as stationary phase by sol-gel technology with simplicity and rapidity is described. Multiple preparation steps in conventional column technology were avoided. The prepared columns exhibit satisfactory chromatographic performances and pronounced selectivity for a wide range of test solutes, and have been successfully used for the separation of nitrotoluene, dimethoxybenzene,alcohols, alkanes, dimethylphenol and cresol isomers.
2005, 16(2): 237-240
Abstract:
A newly synthesized reagent 2-amino-5-mercapto-[1, 3, 4] triazole (MATZ) has been used to fabricate self-assembled monolayers (SAMs) on gold electrode for the first time. The SAMs electrode was characterized by electrochemical methods and scanning electronic microscopy (SEM),the SAMs electrode can be used to determinate dopamine (DA) and uric acid (UA) simultaneously with a detection limit of 8×10-7 mol/L for DA and 1×10-6 mol/L for UA respectively. The SAMs can also be used to detect the contents of DA and UA in synthetic urine sample with satisfactory results.
A newly synthesized reagent 2-amino-5-mercapto-[1, 3, 4] triazole (MATZ) has been used to fabricate self-assembled monolayers (SAMs) on gold electrode for the first time. The SAMs electrode was characterized by electrochemical methods and scanning electronic microscopy (SEM),the SAMs electrode can be used to determinate dopamine (DA) and uric acid (UA) simultaneously with a detection limit of 8×10-7 mol/L for DA and 1×10-6 mol/L for UA respectively. The SAMs can also be used to detect the contents of DA and UA in synthetic urine sample with satisfactory results.
2005, 16(2): 241-244
Abstract:
A novel cyclometalated iridium complex with 1, 3, 4-oxadiazole moiety was synthesized and characterized. Its UV and photoluminescent properties were studied. The strong UV absorption intensity around 462 nm attributed to spin-forbidden triplet metal-ligand charge transfer band and photoluminescence at 518 nm were observed. This indicated that achieved iridium complex could be used as an efficient electrophosphorescent material.
A novel cyclometalated iridium complex with 1, 3, 4-oxadiazole moiety was synthesized and characterized. Its UV and photoluminescent properties were studied. The strong UV absorption intensity around 462 nm attributed to spin-forbidden triplet metal-ligand charge transfer band and photoluminescence at 518 nm were observed. This indicated that achieved iridium complex could be used as an efficient electrophosphorescent material.
2005, 16(2): 245-248
Abstract:
A new form of Cu2O, disk-like structure with 60 nm in thickness and 2 μm in diameter,has been successfully synthesized in bulk quantifies by polyol process in the presence of PVP K-30.
A new form of Cu2O, disk-like structure with 60 nm in thickness and 2 μm in diameter,has been successfully synthesized in bulk quantifies by polyol process in the presence of PVP K-30.
2005, 16(2): 249-252
Abstract:
Ultralong beltlike nanostructures was successfully synthesized for V6O13 crystal by a hydrothermal route. The products are characterized by means of X-ray powder diffraction,transmission electron microscopy and high-resolution transmission electron microscopy. The experimental results give the evidence that the V6O13 nanobelts are pure, structurally uniform and single crystalline, with typical widths of 50 to 300 nm and lengths of up to a few millimeters.
Ultralong beltlike nanostructures was successfully synthesized for V6O13 crystal by a hydrothermal route. The products are characterized by means of X-ray powder diffraction,transmission electron microscopy and high-resolution transmission electron microscopy. The experimental results give the evidence that the V6O13 nanobelts are pure, structurally uniform and single crystalline, with typical widths of 50 to 300 nm and lengths of up to a few millimeters.
2005, 16(2): 253-256
Abstract:
ZSM-5 zeolitic coatings on aluminum have been prepared successfully by in-situ hydrothermal synthesis method and ZSM-5/A1 monolith was formed. The effects of pH value and crystallization time on the in-situ synthesis were discussed.
ZSM-5 zeolitic coatings on aluminum have been prepared successfully by in-situ hydrothermal synthesis method and ZSM-5/A1 monolith was formed. The effects of pH value and crystallization time on the in-situ synthesis were discussed.
2005, 16(2): 257-260
Abstract:
Upon excitation of porphyrin or perylene subunit, the porphyrin-perylene dyad exhibits reversible fluorescence emitting and quenching by formation and neutralization of the protonated porphyrin subunit, thereby providing a prototype of molecular fluorescence switch working in an expanded spectral range.
Upon excitation of porphyrin or perylene subunit, the porphyrin-perylene dyad exhibits reversible fluorescence emitting and quenching by formation and neutralization of the protonated porphyrin subunit, thereby providing a prototype of molecular fluorescence switch working in an expanded spectral range.
2005, 16(2): 261-264
Abstract:
Mesoporous silicoaluminum pillared clays have been synthesized by one-pot gallery-templated synthesis using organomontmorillonite, tetraethyl orthosilicate and alumina isopropoxide as precursor. According to the characterization by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), N2 adsorption isotherms and pyridine adsorption infrared (IR) techniques, the synthetic silicoaluminum pillared clays possess regular porosity with high thermal stability up to 750℃ and Brønsted/Lewis acidity.
Mesoporous silicoaluminum pillared clays have been synthesized by one-pot gallery-templated synthesis using organomontmorillonite, tetraethyl orthosilicate and alumina isopropoxide as precursor. According to the characterization by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), N2 adsorption isotherms and pyridine adsorption infrared (IR) techniques, the synthetic silicoaluminum pillared clays possess regular porosity with high thermal stability up to 750℃ and Brønsted/Lewis acidity.
2005, 16(2): 265-268
Abstract:
Carbon nanotubes were initially chemically modified with an H2SO4-HNO3 treatment,and subsequently activated with Pd-Sn catalytic nuclei via a one-step activation approach. These activated nanotubes were used as precursors for obtaining gold nanoparticles-attached nanotubes via simple electroless plating. This approach provides an efficient method for attachment of metal nanostructures to carbon nanotubes. Such novel hybrid nanostructures are attractive for many applications.
Carbon nanotubes were initially chemically modified with an H2SO4-HNO3 treatment,and subsequently activated with Pd-Sn catalytic nuclei via a one-step activation approach. These activated nanotubes were used as precursors for obtaining gold nanoparticles-attached nanotubes via simple electroless plating. This approach provides an efficient method for attachment of metal nanostructures to carbon nanotubes. Such novel hybrid nanostructures are attractive for many applications.
2005, 16(2): 269-272
Abstract:
Platinum nanoparticles supported on graphite nanofibers (GNFs) were prepared by microwave assistant heating polyol process. TEM images showed that microwave prepared Pt nanoparticles supported on GNFs were small and uniform, and the average diameter was about 3.4 nm. Cyclic voltammetric test showed that Pt/GNFs exhibited very high electrocatalytic activity for methanol oxidation.
Platinum nanoparticles supported on graphite nanofibers (GNFs) were prepared by microwave assistant heating polyol process. TEM images showed that microwave prepared Pt nanoparticles supported on GNFs were small and uniform, and the average diameter was about 3.4 nm. Cyclic voltammetric test showed that Pt/GNFs exhibited very high electrocatalytic activity for methanol oxidation.
2005, 16(2): 273-274
Abstract:
The support materials of ruthenium-based catalysts for ammonia synthesis were prepared using mixed solutions composed of magnesium nitrate, aluminum nitrate and calcium nitrate with a certain ratio. The catalysts supported on complex oxides were more active and the optimal activity temperatures were lower than that supported on single oxide under the same conditions.The catalyst with Mg-Al complex oxide as support prepared by calcinafing hydrotalcite-like compound had significantlyhigher activity, 38.42 mL NH3·h-1·g-1 at 673 K. The BET determination showed that the Mg-Al complex oxide possessed large surface area, 140.95 m2·g-1, similar to γ-Al2O3.
The support materials of ruthenium-based catalysts for ammonia synthesis were prepared using mixed solutions composed of magnesium nitrate, aluminum nitrate and calcium nitrate with a certain ratio. The catalysts supported on complex oxides were more active and the optimal activity temperatures were lower than that supported on single oxide under the same conditions.The catalyst with Mg-Al complex oxide as support prepared by calcinafing hydrotalcite-like compound had significantlyhigher activity, 38.42 mL NH3·h-1·g-1 at 673 K. The BET determination showed that the Mg-Al complex oxide possessed large surface area, 140.95 m2·g-1, similar to γ-Al2O3.
2005, 16(2): 275-278
Abstract:
Using TiO2 and Ti0.5Zr0.5O2 as carriers, the CuO/TiO2 and CuO/Ti0.5Zr0.5O2 catalysts were prepared by the impregnation method with Cu (NO3)2 as active component. The catalytic activities in NO+CO reaction were investigated using a microreactor-GC system, and structure and reducibility of catalysts were characterized by means of physical adsorption, TPR, XRD, NO-TPD technologies. It was found that the activity of CuO/Ti0.5Zr0.5O2 catalyst was higher than that of CuO/TiO2, probably due to the large specific surface area of Ti0.5Zr0.5O2 that played an important role in NO+CO reaction.
Using TiO2 and Ti0.5Zr0.5O2 as carriers, the CuO/TiO2 and CuO/Ti0.5Zr0.5O2 catalysts were prepared by the impregnation method with Cu (NO3)2 as active component. The catalytic activities in NO+CO reaction were investigated using a microreactor-GC system, and structure and reducibility of catalysts were characterized by means of physical adsorption, TPR, XRD, NO-TPD technologies. It was found that the activity of CuO/Ti0.5Zr0.5O2 catalyst was higher than that of CuO/TiO2, probably due to the large specific surface area of Ti0.5Zr0.5O2 that played an important role in NO+CO reaction.
2005, 16(2): 279-281
Abstract:
UV-Vis spectrum was utilized to study the aggregation behaviors of H4THPP2+ in DMF-chloroform mixture and water. It was found that J-aggregation of H4THPP2+ was formed in DMF-chloroform mixture and H-aggregate was formed in aqueous solution with high ionic-strength, as indicated by different spectral characteristics of different H4THPP2+ aggregates.
UV-Vis spectrum was utilized to study the aggregation behaviors of H4THPP2+ in DMF-chloroform mixture and water. It was found that J-aggregation of H4THPP2+ was formed in DMF-chloroform mixture and H-aggregate was formed in aqueous solution with high ionic-strength, as indicated by different spectral characteristics of different H4THPP2+ aggregates.
2005, 16(2): 282-284
Abstract:
Dihydroxy capped triblock oligomers of 2, 2-dimethyltrimethylene carbonate (DTC) and ε-caprolactone (CL) with number-average molecular weight from 3,000 to 12,000 g/mol have been synthesized by alkyl glycol initiator in the presence of yttrium tri (2, 6-di-tert-butyl-4-methylphenolate)s (Y (OAr)3) catalyst. They are expected to be used as macroinitiators for the design of new polymeric materials.
Dihydroxy capped triblock oligomers of 2, 2-dimethyltrimethylene carbonate (DTC) and ε-caprolactone (CL) with number-average molecular weight from 3,000 to 12,000 g/mol have been synthesized by alkyl glycol initiator in the presence of yttrium tri (2, 6-di-tert-butyl-4-methylphenolate)s (Y (OAr)3) catalyst. They are expected to be used as macroinitiators for the design of new polymeric materials.
