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2005 Volume 16 Issue 3
2005, 16(3): 285-286
Abstract:
The solid-phase preparation of diethyl trans-1-alkenephosphonates via seleno-polymer reagent has been reported.
The solid-phase preparation of diethyl trans-1-alkenephosphonates via seleno-polymer reagent has been reported.
2005, 16(3): 287-289
Abstract:
6-Methyluracil and 5-nitro-6-methyluracil react with variable molar quantities of benzoyl chloride in acetonitrile-pyridine at room temperature to give 1-N, 3-N-dibenzoyl-6-methyluracil 3b and 1-N-benzoyl-5-nitro-5-methyluracil 4b.The reactive rates of debenzoylation of 3b and 4b were investigated.
6-Methyluracil and 5-nitro-6-methyluracil react with variable molar quantities of benzoyl chloride in acetonitrile-pyridine at room temperature to give 1-N, 3-N-dibenzoyl-6-methyluracil 3b and 1-N-benzoyl-5-nitro-5-methyluracil 4b.The reactive rates of debenzoylation of 3b and 4b were investigated.
2005, 16(3): 290-292
Abstract:
The phenomenon of migration of the silyl groups from α-oxygen to β-oxygen in sodium aldol reaction was observed for the first time in this paper.
The phenomenon of migration of the silyl groups from α-oxygen to β-oxygen in sodium aldol reaction was observed for the first time in this paper.
2005, 16(3): 293-295
Abstract:
Xanthenedione derivatives were prepared through InCl3·4H2O promoted condensation of aldehydes with 5, 5-dimethyl-1, 3-cyclohexandione in [bmim] [BF4]. The advantages of this method are:simple operation, environmental benign and high efficiency. Moreover, the reaction media and the catalyst can be recovered and reused effectively for at least six times.
Xanthenedione derivatives were prepared through InCl3·4H2O promoted condensation of aldehydes with 5, 5-dimethyl-1, 3-cyclohexandione in [bmim] [BF4]. The advantages of this method are:simple operation, environmental benign and high efficiency. Moreover, the reaction media and the catalyst can be recovered and reused effectively for at least six times.
2005, 16(3): 296-298
Abstract:
A series of novel pentaerythritol-based carbosilane dendrimers have been synthesized.Using pentaerythritol-based tetraallyl ether as core molecule, the dendrimers have been prepared up to the third generation with 108 allyl groups on the periphery by alternate allylation-hydrosilylation approach.
A series of novel pentaerythritol-based carbosilane dendrimers have been synthesized.Using pentaerythritol-based tetraallyl ether as core molecule, the dendrimers have been prepared up to the third generation with 108 allyl groups on the periphery by alternate allylation-hydrosilylation approach.
2005, 16(3): 299-302
Abstract:
The synthesis of 2, 4, 6-triisopropyl-1, 3, 5-trioxane with high yield and desirable selectivity from solvent-free cyclotrimerization of isobutyraldehyde catalyzed by ionic liquids was reported in this work.
The synthesis of 2, 4, 6-triisopropyl-1, 3, 5-trioxane with high yield and desirable selectivity from solvent-free cyclotrimerization of isobutyraldehyde catalyzed by ionic liquids was reported in this work.
2005, 16(3): 303-306
Abstract:
A new porphyrin-fluorescein hybrid 2 (Fl-PPTPP) has been synthesized and characterized by UV-Vis, IR, 1H-NMR, ESI-MS and elemental analysis. The supramolecular self-assembly of Fl-PPTPP with amino-porphyrinatomanganese (Ⅲ) [Mn(Ⅲ) (p-APTPP)C1] by hydrogen-bonding was studied using fluorescence spectroscopic titration and ESI-MS.
A new porphyrin-fluorescein hybrid 2 (Fl-PPTPP) has been synthesized and characterized by UV-Vis, IR, 1H-NMR, ESI-MS and elemental analysis. The supramolecular self-assembly of Fl-PPTPP with amino-porphyrinatomanganese (Ⅲ) [Mn(Ⅲ) (p-APTPP)C1] by hydrogen-bonding was studied using fluorescence spectroscopic titration and ESI-MS.
Unexpected Side Reaction in the Intermolecular N-H Insertion of Phenyl Diazoacetates with Arylamines
2005, 16(3): 307-310
Abstract:
Unexpected side reaction is discovered from the N-H insertion of phenyl diazoacetates with arylamines in the presence of Rh2(OAc)4 catalyst. This side reaction is not evident with copper catalysts such as Cu (acac)2 or Cu (OTf)2. Good yieldof the N-H insertion was obtained by using 0.2% of copper catalyst.
Unexpected side reaction is discovered from the N-H insertion of phenyl diazoacetates with arylamines in the presence of Rh2(OAc)4 catalyst. This side reaction is not evident with copper catalysts such as Cu (acac)2 or Cu (OTf)2. Good yieldof the N-H insertion was obtained by using 0.2% of copper catalyst.
2005, 16(3): 311-314
Abstract:
Methylenedioxyphenyl unit displays a significant stereoelectronic effect in some key transformations in the total synthesis of cephalotaxine. The ring-strain of methylenedioxy ring may account for some important facile ring-skeleton rearrangements.
Methylenedioxyphenyl unit displays a significant stereoelectronic effect in some key transformations in the total synthesis of cephalotaxine. The ring-strain of methylenedioxy ring may account for some important facile ring-skeleton rearrangements.
2005, 16(3): 315-316
Abstract:
Halotosyloxylation reaction of alkynes with iodine or NBS or NCS was efficiently promoted by the poly {[4-(hydroxyl) (tosoyloxyl) iodo] styrene}.
Halotosyloxylation reaction of alkynes with iodine or NBS or NCS was efficiently promoted by the poly {[4-(hydroxyl) (tosoyloxyl) iodo] styrene}.
2005, 16(3): 317-320
Abstract:
H-phosphonates were conveniently prepared by direct transesterification of diphenyl phosphite (DPP) with the corresponding alcohols, without further purification they were reacted with branched peptide methyl ester (L-Leu2-L-LysOMe) through Atherton-Todd method, a series of different substituted alkyloxy (N-phosphoryl-L-Leu)2-L-LysOMe were synthesized, and their structures were confirmed by 31p NMR, ESI-MS, 1H NMR, 13C NMR, IR and elemental analysis.The approach possesses the advantages of easy operation, high yield and inexpensive phosphorylating reagent.
H-phosphonates were conveniently prepared by direct transesterification of diphenyl phosphite (DPP) with the corresponding alcohols, without further purification they were reacted with branched peptide methyl ester (L-Leu2-L-LysOMe) through Atherton-Todd method, a series of different substituted alkyloxy (N-phosphoryl-L-Leu)2-L-LysOMe were synthesized, and their structures were confirmed by 31p NMR, ESI-MS, 1H NMR, 13C NMR, IR and elemental analysis.The approach possesses the advantages of easy operation, high yield and inexpensive phosphorylating reagent.
2005, 16(3): 321-324
Abstract:
Benzoin condensation promoted efficiently in three imidazolium based room temperature ionic liquids [bmim]Br, [bmim]BF4 and [Bnmim]BF4 is reported for the first time. Benzoins were obtained in up to 91% yield within less than 30 min under mild conditions.
Benzoin condensation promoted efficiently in three imidazolium based room temperature ionic liquids [bmim]Br, [bmim]BF4 and [Bnmim]BF4 is reported for the first time. Benzoins were obtained in up to 91% yield within less than 30 min under mild conditions.
2005, 16(3): 325-326
Abstract:
Alkynyl selenide reacted with cesium arylselenolate in commercial THF at r.t under N2 to afford (Z)-1, 2-bis (arylseleno)-1-alkene in high yields.
Alkynyl selenide reacted with cesium arylselenolate in commercial THF at r.t under N2 to afford (Z)-1, 2-bis (arylseleno)-1-alkene in high yields.
2005, 16(3): 327-330
Abstract:
A novel catalytic system, ZnCl2 supported on alumina, was found to be an efficient and readily available medium for the solvent-free Friedel-Crafts acylation reactions under microwave irradiation. Good yields and high catalytic efficiencies were observed within short reaction times.Comparing with silica gel, alumina was more efficient under the same conditions.
A novel catalytic system, ZnCl2 supported on alumina, was found to be an efficient and readily available medium for the solvent-free Friedel-Crafts acylation reactions under microwave irradiation. Good yields and high catalytic efficiencies were observed within short reaction times.Comparing with silica gel, alumina was more efficient under the same conditions.
2005, 16(3): 331-334
Abstract:
Asymmetric intramolecular cyclopropanation of allylic diazoacetate was investigated using a chiral (β-diketone)-copper complex as catalyst, excellent yield and enantioselectivity were achieved. Some factors influencing enantioselectivity were discussed.
Asymmetric intramolecular cyclopropanation of allylic diazoacetate was investigated using a chiral (β-diketone)-copper complex as catalyst, excellent yield and enantioselectivity were achieved. Some factors influencing enantioselectivity were discussed.
2005, 16(3): 335-337
Abstract:
A series of 3-pyridinyl-6-aryl-1, 2, 4-triazolo [3, 4-b] [1, 3, 4] thiadiazoles (PATT) were prepared, the structures were confirmed by IR and 1H NMR spectra. The results of cyclic voltammetry measurements imply that all these compounds have a higher electron affinity (EA)than 2-(4-biphenyl)-5-(4-tert-butyl phenyl)-1, 3, 4-oxadiazole (PBD) which implies that PATT could be acting as better electron acceptors than widely used electron transporting material PBD.
A series of 3-pyridinyl-6-aryl-1, 2, 4-triazolo [3, 4-b] [1, 3, 4] thiadiazoles (PATT) were prepared, the structures were confirmed by IR and 1H NMR spectra. The results of cyclic voltammetry measurements imply that all these compounds have a higher electron affinity (EA)than 2-(4-biphenyl)-5-(4-tert-butyl phenyl)-1, 3, 4-oxadiazole (PBD) which implies that PATT could be acting as better electron acceptors than widely used electron transporting material PBD.
2005, 16(3): 338-340
Abstract:
Catalytic hydrogenation of SBS was performed for the first time in polyether molten salt with Ru/TPPTS complex as catalyst. Experimental results showed that the hydrogenation degree can be enhanced significantly by the addition of triphenylphosphine (TPP). When the molar ratio of TPP, TPPTS and Ru is 2:5:1, 89% hydrogenation degree can be achieved after 12 h under reaction conditions of 5.0 MPa and 150℃. The ionic liquid containing catalyst can be reused three times without obvious changes in the catalytic selectivity and activity.
Catalytic hydrogenation of SBS was performed for the first time in polyether molten salt with Ru/TPPTS complex as catalyst. Experimental results showed that the hydrogenation degree can be enhanced significantly by the addition of triphenylphosphine (TPP). When the molar ratio of TPP, TPPTS and Ru is 2:5:1, 89% hydrogenation degree can be achieved after 12 h under reaction conditions of 5.0 MPa and 150℃. The ionic liquid containing catalyst can be reused three times without obvious changes in the catalytic selectivity and activity.
2005, 16(3): 341-344
Abstract:
Two fluorescent pentamethine and a squarylium indocyanines containing at least one p-carboxybenzyl group on N atoms in the heterocyclic rings were synthesized. They had good water solubility and photostability. Their maximum absorption and maximum emission were 600-700 nm in water. When it was anchored onto nanostructured TiO2 electrode, compared with in water, the squaraine showed double absorption peaks (one blue shifted and another red shifted)and absorption intensity of the red shift peak increased with the increase of the time of irradiation.The intensity of the blue one decreased simultaneously. We proposed that the presence of two electronic charge forms of squaraine anchored on the TiO2 film might be the reason.
Two fluorescent pentamethine and a squarylium indocyanines containing at least one p-carboxybenzyl group on N atoms in the heterocyclic rings were synthesized. They had good water solubility and photostability. Their maximum absorption and maximum emission were 600-700 nm in water. When it was anchored onto nanostructured TiO2 electrode, compared with in water, the squaraine showed double absorption peaks (one blue shifted and another red shifted)and absorption intensity of the red shift peak increased with the increase of the time of irradiation.The intensity of the blue one decreased simultaneously. We proposed that the presence of two electronic charge forms of squaraine anchored on the TiO2 film might be the reason.
2005, 16(3): 345-348
Abstract:
2-(4-Dimethylaminophenyl)-5-fluoro-6-(morpholin-4-yl)- 1H-benzimidazole(1) has been synthesized and characterized by 1H-NMR, MS and elemental analysis. UV-Vis spectra of the aqueous solutions at different pH values reveal that compound 1 can combine three protons. Its three protonation constants are determined by spectrophotometry and calculated by non-linear least squares. The results of steady-state fluorescence measurements indicate that a special interaction occurs between compound 1 and calf thymus DNA, of which the binding constant, Kb, is (2.30 ±0.10)×l04 L/mol. Compound 1 in the concentration range of 10-8 to 1.2×l0-6 mol/L could be used for quantitative determination of DNA.
2-(4-Dimethylaminophenyl)-5-fluoro-6-(morpholin-4-yl)- 1H-benzimidazole(1) has been synthesized and characterized by 1H-NMR, MS and elemental analysis. UV-Vis spectra of the aqueous solutions at different pH values reveal that compound 1 can combine three protons. Its three protonation constants are determined by spectrophotometry and calculated by non-linear least squares. The results of steady-state fluorescence measurements indicate that a special interaction occurs between compound 1 and calf thymus DNA, of which the binding constant, Kb, is (2.30 ±0.10)×l04 L/mol. Compound 1 in the concentration range of 10-8 to 1.2×l0-6 mol/L could be used for quantitative determination of DNA.
2005, 16(3): 349-352
Abstract:
We synthesized and characterized photoactivatable phospholipidic probes 1-3. These probes have the perfluorinated aryl azide function at the polar head of phospholipid. They are stable in dark and become highly reactive upon photoirradiation. The preliminary results suggest that they are promising tools to study the topology of membrane proteins and protein-lipid interactions using photolabeling approach.
We synthesized and characterized photoactivatable phospholipidic probes 1-3. These probes have the perfluorinated aryl azide function at the polar head of phospholipid. They are stable in dark and become highly reactive upon photoirradiation. The preliminary results suggest that they are promising tools to study the topology of membrane proteins and protein-lipid interactions using photolabeling approach.
2005, 16(3): 353-355
Abstract:
From the marine sponge Jaspis sp., a new isomalabaricane triterpenoid 22, 23-dihydrostellettin D (1) was isolated, and its structure was established on the basis of IR, MS and extensive 2D NMR spectroscopic analysis. It is a unique skeleton compound rarely obtained from Chinese marine organisms.
From the marine sponge Jaspis sp., a new isomalabaricane triterpenoid 22, 23-dihydrostellettin D (1) was isolated, and its structure was established on the basis of IR, MS and extensive 2D NMR spectroscopic analysis. It is a unique skeleton compound rarely obtained from Chinese marine organisms.
2005, 16(3): 356-358
Abstract:
Two new steroids, nanjiols D and E, were isolated from the soft coral Nephthea bayeri.Their structures were characterized by spectroscopic methods and comparison with known compounds.
Two new steroids, nanjiols D and E, were isolated from the soft coral Nephthea bayeri.Their structures were characterized by spectroscopic methods and comparison with known compounds.
2005, 16(3): 359-361
Abstract:
A novel saponin was isolated from the transformed products of ginsenoside Rh1 by Bacillus subtilis. It's structure was determined to be 3-O-β-D-glucopyranosyl-6-O-β-D-glucopyranosyl-20 (S)-protopanaxatriol on the basis of the spectral data.
A novel saponin was isolated from the transformed products of ginsenoside Rh1 by Bacillus subtilis. It's structure was determined to be 3-O-β-D-glucopyranosyl-6-O-β-D-glucopyranosyl-20 (S)-protopanaxatriol on the basis of the spectral data.
2005, 16(3): 362-364
Abstract:
Two new eremophilanolides, tsoongianolide E and F, were isolated from Senecio tsoongianus. Their structures were elucidated on the basis of NMR and MS spectra. Both of these two compounds showed in vitro cytotoxicity to cultured KB and A-549 cancer cell lines.
Two new eremophilanolides, tsoongianolide E and F, were isolated from Senecio tsoongianus. Their structures were elucidated on the basis of NMR and MS spectra. Both of these two compounds showed in vitro cytotoxicity to cultured KB and A-549 cancer cell lines.
2005, 16(3): 365-366
Abstract:
Two new acetylenic compounds were isolated from the roots of Asparagus gobicus.Their structures were elucidated by spectroscopic methods including 2D NMR techniques.
Two new acetylenic compounds were isolated from the roots of Asparagus gobicus.Their structures were elucidated by spectroscopic methods including 2D NMR techniques.
2005, 16(3): 367-368
Abstract:
A new nitro tetrahydronprotoberberins alkaloid, 1-nitro-apocavidine was isolated from Corydalis saxicola Bunting. The structure was established by spectroscopic methods.
A new nitro tetrahydronprotoberberins alkaloid, 1-nitro-apocavidine was isolated from Corydalis saxicola Bunting. The structure was established by spectroscopic methods.
2005, 16(3): 369-371
Abstract:
A new andrographolide metabolite 1 was isolated from human urine samples after oral administration. The structure was determined to be 3-carbonylandrographolide-19-O-β-D-glucuronide on the basis of chemical evidences and spectral analysis, especially by 2D-NMR techniques.
A new andrographolide metabolite 1 was isolated from human urine samples after oral administration. The structure was determined to be 3-carbonylandrographolide-19-O-β-D-glucuronide on the basis of chemical evidences and spectral analysis, especially by 2D-NMR techniques.
2005, 16(3): 372-374
Abstract:
A novel dimeric complex[Ru3Ⅲ,Ⅲ,Ⅱ(μ3-O)(μ-CH3COO) (CO)]2 (μ-dppf)(μ-odppf) (dppf=1, l'-bis(diphenylphosphio) ferrocene, odppf=1, 1'-bis(oxodiphenylphosphoranyl)ferrocene) (1) of oxo-centered triruthenium-aectate cluster units was synthesized and characterized by X-ray crystallography. Compound 1 exhibits a cyclic structure formed by linkages of two triruthenium cluster units Ru3Ⅲ,Ⅲ, Ⅱ (μ3-O)(μ-CH3COO)6(CO) through dppf and odppf ligands, respectively. The diameter of the molecular loop is ca. 1.0 nm.
A novel dimeric complex[Ru3Ⅲ,Ⅲ,Ⅱ(μ3-O)(μ-CH3COO) (CO)]2 (μ-dppf)(μ-odppf) (dppf=1, l'-bis(diphenylphosphio) ferrocene, odppf=1, 1'-bis(oxodiphenylphosphoranyl)ferrocene) (1) of oxo-centered triruthenium-aectate cluster units was synthesized and characterized by X-ray crystallography. Compound 1 exhibits a cyclic structure formed by linkages of two triruthenium cluster units Ru3Ⅲ,Ⅲ, Ⅱ (μ3-O)(μ-CH3COO)6(CO) through dppf and odppf ligands, respectively. The diameter of the molecular loop is ca. 1.0 nm.
2005, 16(3): 375-378
Abstract:
Orthohexagonal slices assembled by ZnSe quantum dots were synthesized through emulsion liquid membrane system. These orthohexagonal slices were 1.5-3.5 μm in side length and were self-assembled by ZnSe quantum dots of 2-3 nm. It was proposed the surfactant molecules on ZnSe quantum dots played a key role in the self-assembly process.
Orthohexagonal slices assembled by ZnSe quantum dots were synthesized through emulsion liquid membrane system. These orthohexagonal slices were 1.5-3.5 μm in side length and were self-assembled by ZnSe quantum dots of 2-3 nm. It was proposed the surfactant molecules on ZnSe quantum dots played a key role in the self-assembly process.
2005, 16(3): 379-381
Abstract:
The effect of Ultra-violet light on the structure and motion of the polyvinyl alcohol(PVA) chains was studied by 1H NMR, spin-lattice relaxation and IR spectroscopy. The results indicated that with the increase of irradiation time, the intensity of the polymer hydroxyl proton peaks decreased and finally vanished, which suggested the self-condensation between the hydroxyl groups proceeded. No methyl proton peaks appeared in the spectra after irradiation shows that there is no cleavage of polymer chain. The longer the irradiation time is, the wider the proton peak of the residual water of the solvent is and it shifted toward low field. This result implies that the hydrogen bonds formed between the polymer and the residual water. The absorption peak of hydroxyl group of the polymer moves toward the lower wave number in the IR spectrum that showed the existence of the hydrogen bonds between the PVA macromolecules.
The effect of Ultra-violet light on the structure and motion of the polyvinyl alcohol(PVA) chains was studied by 1H NMR, spin-lattice relaxation and IR spectroscopy. The results indicated that with the increase of irradiation time, the intensity of the polymer hydroxyl proton peaks decreased and finally vanished, which suggested the self-condensation between the hydroxyl groups proceeded. No methyl proton peaks appeared in the spectra after irradiation shows that there is no cleavage of polymer chain. The longer the irradiation time is, the wider the proton peak of the residual water of the solvent is and it shifted toward low field. This result implies that the hydrogen bonds formed between the polymer and the residual water. The absorption peak of hydroxyl group of the polymer moves toward the lower wave number in the IR spectrum that showed the existence of the hydrogen bonds between the PVA macromolecules.
2005, 16(3): 382-384
Abstract:
The recognition interaction of rhodamine B (RB) with DNA was studied in pH 7.5 Britton-Robinson (B-R) buffer solution by electrochemical techniques. An irreversible oxidation peak at glassy carbon electrode was obtained at +0.92V (vs. SCE). After the addition of DNA into the RB solution, the peak current of RB decreased apparently without the shift of peak potential. The electrochemical parameters such as the charge transfer coefficient α and the electrode reaction standard rate constant ks of RB in the absence and presence of DNA were determined, which did not change, indicating that a non-electroactive complex was formed, so the concentration of RB in the solution decreased and the peak current decreased correspondingly.
The recognition interaction of rhodamine B (RB) with DNA was studied in pH 7.5 Britton-Robinson (B-R) buffer solution by electrochemical techniques. An irreversible oxidation peak at glassy carbon electrode was obtained at +0.92V (vs. SCE). After the addition of DNA into the RB solution, the peak current of RB decreased apparently without the shift of peak potential. The electrochemical parameters such as the charge transfer coefficient α and the electrode reaction standard rate constant ks of RB in the absence and presence of DNA were determined, which did not change, indicating that a non-electroactive complex was formed, so the concentration of RB in the solution decreased and the peak current decreased correspondingly.
2005, 16(3): 385-388
Abstract:
The intermediates of the Appel coupling reagents were studied in acetonitrile,dimethoxyethane and dioxane by 31P NMR,13C NMR spectrum and ESI-MS. In dioxane a new high coordinated phosphorous compound with 31p NMR shift at -39 ppm was observed. The ESI-MS showed that it could be a penta-coordinated phosphorous compound containing dioxane. The carboxyl activated intermediates were also studied in three solvents.
The intermediates of the Appel coupling reagents were studied in acetonitrile,dimethoxyethane and dioxane by 31P NMR,13C NMR spectrum and ESI-MS. In dioxane a new high coordinated phosphorous compound with 31p NMR shift at -39 ppm was observed. The ESI-MS showed that it could be a penta-coordinated phosphorous compound containing dioxane. The carboxyl activated intermediates were also studied in three solvents.
2005, 16(3): 389-392
Abstract:
The urea denatured recombinant human granulocyte colony-stimulating factor (rhGCSF) which was expressed in Escheriachia coli (E. coli) was refolded with simultaneous purification by strong anion exchange chromatography (SAX) in the presence of low concentration of urea. The effect of urea concentration on this refolding process was investigated. The obtained refolded rhG-CSF has a high specific activity of 2.3×108 U/mg, demonstrating that the proteins were completely refolded during the chromatographic process. With only one step by SAX in 40 min, purity and mass recovery of the refolded and purified rhG-CSF were 97% and 43%, respectively.
The urea denatured recombinant human granulocyte colony-stimulating factor (rhGCSF) which was expressed in Escheriachia coli (E. coli) was refolded with simultaneous purification by strong anion exchange chromatography (SAX) in the presence of low concentration of urea. The effect of urea concentration on this refolding process was investigated. The obtained refolded rhG-CSF has a high specific activity of 2.3×108 U/mg, demonstrating that the proteins were completely refolded during the chromatographic process. With only one step by SAX in 40 min, purity and mass recovery of the refolded and purified rhG-CSF were 97% and 43%, respectively.
2005, 16(3): 393-396
Abstract:
Five coal char samples were burnt in thermobalance with ramp heating rate of 30 K/min.The pore structure of these char samples was studied through mercury intrusion method.Combined with the kinetic theory of gases, the data of surface area was used in fitting the results.As a result, the kinetic triplet was given. The analysis showed that five char samples share almost the same intrinsic activation energy of the overall reaction. The phenomenological implication of the derived combustion rate equation was given.
Five coal char samples were burnt in thermobalance with ramp heating rate of 30 K/min.The pore structure of these char samples was studied through mercury intrusion method.Combined with the kinetic theory of gases, the data of surface area was used in fitting the results.As a result, the kinetic triplet was given. The analysis showed that five char samples share almost the same intrinsic activation energy of the overall reaction. The phenomenological implication of the derived combustion rate equation was given.
2005, 16(3): 397-400
Abstract:
Polypropylene microporous membranes were treated with plasma in a mixture of N2 and H2 (1:2 in volume). Attenuated total reflectance Fourier transform infrared spectroscopy(ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and ultra-violet (UV) spectra demonstratedthe success of grafting amino groups. The density of the polar amino groups on the membrane surface is about 0.59 μmol/cm2. The as-treated membranes were successively applied to the in situ synthesis of oligonucleotides and an average coupling yield was more than 98%. The surface feature of the treated membrane is suggested to be responsible for its advantage over a glass slide.
Polypropylene microporous membranes were treated with plasma in a mixture of N2 and H2 (1:2 in volume). Attenuated total reflectance Fourier transform infrared spectroscopy(ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and ultra-violet (UV) spectra demonstratedthe success of grafting amino groups. The density of the polar amino groups on the membrane surface is about 0.59 μmol/cm2. The as-treated membranes were successively applied to the in situ synthesis of oligonucleotides and an average coupling yield was more than 98%. The surface feature of the treated membrane is suggested to be responsible for its advantage over a glass slide.
2005, 16(3): 401-404
Abstract:
In this paper, polyurethane resins were synthesized from liquefied benzylated wood and TDI (toluene diisocyanate)-TMP (trihydromethylene propane) prepolymer. And the relation between microphase structure and properties of PU samples were also studied. The results indicated that coatings obtained had good mechanical and thermal properties. The amount of the curing agent has great effect on the degree of phase segregation. In addition, with increased the curing agent amount, the thermal stabilities were also improved.
In this paper, polyurethane resins were synthesized from liquefied benzylated wood and TDI (toluene diisocyanate)-TMP (trihydromethylene propane) prepolymer. And the relation between microphase structure and properties of PU samples were also studied. The results indicated that coatings obtained had good mechanical and thermal properties. The amount of the curing agent has great effect on the degree of phase segregation. In addition, with increased the curing agent amount, the thermal stabilities were also improved.
2005, 16(3): 405-408
Abstract:
Silicon inserted π conjugated copolymer was synthesized by Heck reaction with moderate molecular weight. This silicon containing copolymer is thermally stable to 400℃, while emission of this polymer is blue-shifted compared with polyphenylenevinylene greenish emission. It shows potential application as organic emitter in OLED.
Silicon inserted π conjugated copolymer was synthesized by Heck reaction with moderate molecular weight. This silicon containing copolymer is thermally stable to 400℃, while emission of this polymer is blue-shifted compared with polyphenylenevinylene greenish emission. It shows potential application as organic emitter in OLED.
2005, 16(3): 409-412
Abstract:
The present work reports the irradiation induced grafting polymerization onto nano-sized CaCO3 particles, mainly focusing on the effects of pretreatment with silane coupling agent. It is proved that poly (butyl acrylate) can be grafted onto the nanoparticles using the technical route suggested by the authors, and the silane treatment of the nanoparticles promotes the grafting polymerization.
The present work reports the irradiation induced grafting polymerization onto nano-sized CaCO3 particles, mainly focusing on the effects of pretreatment with silane coupling agent. It is proved that poly (butyl acrylate) can be grafted onto the nanoparticles using the technical route suggested by the authors, and the silane treatment of the nanoparticles promotes the grafting polymerization.
2005, 16(3): 413-415
Abstract:
A defect-free SAPO-44 zeolite membrane firmly anchored the porous α-Al2O3 plate substrate was successfully synthesized. The separating results showed that the H2/N2 and H2/CO permselectivities were higher than those of the corresponding Knudsen diffusion and the substrate,attaining 5.78 and 7.15 respectively.
A defect-free SAPO-44 zeolite membrane firmly anchored the porous α-Al2O3 plate substrate was successfully synthesized. The separating results showed that the H2/N2 and H2/CO permselectivities were higher than those of the corresponding Knudsen diffusion and the substrate,attaining 5.78 and 7.15 respectively.
2005, 16(3): 416-418
Abstract:
A unique method for preparing a coaxial dual-microelectrode sensor by vaporizing the nano-thickness Au layer on the DNA modified carbon fiber micro-column electrode was illustrated.The dual-electrode showed particular merit for determination in biological systems.
A unique method for preparing a coaxial dual-microelectrode sensor by vaporizing the nano-thickness Au layer on the DNA modified carbon fiber micro-column electrode was illustrated.The dual-electrode showed particular merit for determination in biological systems.
2005, 16(3): 419-422
Abstract:
The Potential step measurements are carried out on single beads of nickel hydroxide and the results are interpreted with a dual structure model featuring fast and slow diffusing components.The intrinsic diffusion coefficients for the two components are found to be in the order of magnitude 10-7 and 10-13~10-14 cm2s-1, respectively, with an apparent value for the slow component in the order of 10-10 cm2s-1.
The Potential step measurements are carried out on single beads of nickel hydroxide and the results are interpreted with a dual structure model featuring fast and slow diffusing components.The intrinsic diffusion coefficients for the two components are found to be in the order of magnitude 10-7 and 10-13~10-14 cm2s-1, respectively, with an apparent value for the slow component in the order of 10-10 cm2s-1.
2005, 16(3): 423-426
Abstract:
A pyrazoline-containing starburst molecule, 4,4',4"-tris [(1,3-diphenyl-4,5-dihydro-1Hpyrazol)-5-yl]-triphenylamine (Tris-5-DPP), was synthesized in a facile way, which can form amorphous thin films with glass transition temperature as high as 136℃.
A pyrazoline-containing starburst molecule, 4,4',4"-tris [(1,3-diphenyl-4,5-dihydro-1Hpyrazol)-5-yl]-triphenylamine (Tris-5-DPP), was synthesized in a facile way, which can form amorphous thin films with glass transition temperature as high as 136℃.
