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2004 Volume 15 Issue 7
2004, 15(7): 757-758
Abstract:
The stereoselective synthesis of the C1-C7fragment (3R,4S,6R)-3,4-di[(tert-butyl-dimethylsilyl)oxy]-7-hydroxy-6-methylheptan-2-one, which is the crucial intermediate for synthesis of the HIV-1 protease inhibitive didemnaketals, was developed via 12 steps from the natural (+)-pulegone.
The stereoselective synthesis of the C1-C7fragment (3R,4S,6R)-3,4-di[(tert-butyl-dimethylsilyl)oxy]-7-hydroxy-6-methylheptan-2-one, which is the crucial intermediate for synthesis of the HIV-1 protease inhibitive didemnaketals, was developed via 12 steps from the natural (+)-pulegone.
2004, 15(7): 759-761
Abstract:
A concise and efficient synthesis of the new compounds tetrahydroisoquino[2,1-c] [1,3] benzodiazepine 5 and 7 is reported.
A concise and efficient synthesis of the new compounds tetrahydroisoquino[2,1-c] [1,3] benzodiazepine 5 and 7 is reported.
2004, 15(7): 762-764
Abstract:
A concise and stereoselective synthesis of cathasterone's side chain using methyl isopropyl ketone 3 as the fragment is described.
A concise and stereoselective synthesis of cathasterone's side chain using methyl isopropyl ketone 3 as the fragment is described.
2004, 15(7): 765-767
Abstract:
Six new 13-O-acylavermectin B1 aglycones(3~8) were synthesized from avermectin B1 aglycone and their bioactivities were evaluated against Spodoptera exigua, Spodoptera eridania, Tetranychus urticae and Aphis fabae.
Six new 13-O-acylavermectin B1 aglycones(3~8) were synthesized from avermectin B1 aglycone and their bioactivities were evaluated against Spodoptera exigua, Spodoptera eridania, Tetranychus urticae and Aphis fabae.
2004, 15(7): 768-770
Abstract:
The enzymatic synthesis of a tetrapeptide Phac-Met-Gly-Trp-Met-OEt is reported. It was synthesized by coupling Phac-Met-OEt with Gly-OMe·HCl, Trp-OMe and Met-OEt successively, catalyzed by α-chymotrypsin, papain and α-chymotrypsin respectively. The results of FAB-MS showed that the products had the correct molecular mass.
The enzymatic synthesis of a tetrapeptide Phac-Met-Gly-Trp-Met-OEt is reported. It was synthesized by coupling Phac-Met-OEt with Gly-OMe·HCl, Trp-OMe and Met-OEt successively, catalyzed by α-chymotrypsin, papain and α-chymotrypsin respectively. The results of FAB-MS showed that the products had the correct molecular mass.
2004, 15(7): 771-773
Abstract:
New photoaffinity ligand candidates were synthesized based on 5-t-butyl-2-(4-(substituted-ethynyl)phenyl)-1, 3-dithiane for the noncompetitive blocker site on the gamma-aminobutyric acid-gated chloride channel. Their half-maximal inhibition concentrations ranged from 4 to 32 nmol/L as measured by 4'-ethynyl-4-n-[2,3-3H2]-propylbicycloorthobenzoate (3H EBOB) assay.
New photoaffinity ligand candidates were synthesized based on 5-t-butyl-2-(4-(substituted-ethynyl)phenyl)-1, 3-dithiane for the noncompetitive blocker site on the gamma-aminobutyric acid-gated chloride channel. Their half-maximal inhibition concentrations ranged from 4 to 32 nmol/L as measured by 4'-ethynyl-4-n-[2,3-3H2]-propylbicycloorthobenzoate (3H EBOB) assay.
2004, 15(7): 774-776
Abstract:
The hydroaminomethylation of 1-dodecene catalyzed by water soluble rhodium complex RhCl(CO)(TPPTS)2 in the presence of surfactant CTAB was investigated. High reactivity and selectivity for tertiary amine were achieved under relatively mild conditions.
The hydroaminomethylation of 1-dodecene catalyzed by water soluble rhodium complex RhCl(CO)(TPPTS)2 in the presence of surfactant CTAB was investigated. High reactivity and selectivity for tertiary amine were achieved under relatively mild conditions.
2004, 15(7): 777-778
Abstract:
An unusual reductive ring-opening reaction of phthalimide with sodium hydride in anhydrous DMF was observed for the first time. The presumed mechanism was described in detail.
An unusual reductive ring-opening reaction of phthalimide with sodium hydride in anhydrous DMF was observed for the first time. The presumed mechanism was described in detail.
2004, 15(7): 779-780
Abstract:
In this investigation, a clean, atomic economic and direct synthesis of oxygenates (methanol, ethanol) form water and methane via dielectric-barrier discharge was developed at room temperature and under atmospheric pressure. The effect of discharge voltage on this process was studied. The results showed that the conversion of water can be as high as 7%, the selectivity of methanol and ethanol can be as high as 100%.
In this investigation, a clean, atomic economic and direct synthesis of oxygenates (methanol, ethanol) form water and methane via dielectric-barrier discharge was developed at room temperature and under atmospheric pressure. The effect of discharge voltage on this process was studied. The results showed that the conversion of water can be as high as 7%, the selectivity of methanol and ethanol can be as high as 100%.
2004, 15(7): 781-784
Abstract:
Two protected tigogenyl glycosides were synthesized via parallel synthesis of oligosaccharide. Using chemical synthesis and conformational analysis the reason of the proton signal of 2" acetyl group shifted up field in 1H-NMR was discussed.
Two protected tigogenyl glycosides were synthesized via parallel synthesis of oligosaccharide. Using chemical synthesis and conformational analysis the reason of the proton signal of 2" acetyl group shifted up field in 1H-NMR was discussed.
2004, 15(7): 785-786
Abstract:
The synthesis of novel nucleoside analog (3R)-2,3-dideoxy-3-(N-hydroxy-N-methylamino)-L-arabinofuranosyl uracil was studied. A twelve-step synthetic route, started from L-ascorbic acid, was designed, and the final product was obtained in 20.8% yield.
The synthesis of novel nucleoside analog (3R)-2,3-dideoxy-3-(N-hydroxy-N-methylamino)-L-arabinofuranosyl uracil was studied. A twelve-step synthetic route, started from L-ascorbic acid, was designed, and the final product was obtained in 20.8% yield.
2004, 15(7): 787-790
Abstract:
We report a facile and high-yielding procedure for preparing biphenyltetracarboxylic dianhydrides (BPDAs). This method relies on a nickel-catalyzed electroreductive coupling reaction of dimethyl 3-chorophthalate (3-DMCP) and/or dimethyl 4-chorophthalate (4-DMCP) with subsequent hydrolysis of tetra-ester and dehydration of tetra-acid.
We report a facile and high-yielding procedure for preparing biphenyltetracarboxylic dianhydrides (BPDAs). This method relies on a nickel-catalyzed electroreductive coupling reaction of dimethyl 3-chorophthalate (3-DMCP) and/or dimethyl 4-chorophthalate (4-DMCP) with subsequent hydrolysis of tetra-ester and dehydration of tetra-acid.
2004, 15(7): 791-793
Abstract:
A new sesquiterpenoid was obstained from the leaves of Magnolia delavayi. Its structure was determined as 8β-acetoxy-10α-ethyloxy-guaia-4α, 11-diol on the basis of spectral evidence.
A new sesquiterpenoid was obstained from the leaves of Magnolia delavayi. Its structure was determined as 8β-acetoxy-10α-ethyloxy-guaia-4α, 11-diol on the basis of spectral evidence.
2004, 15(7): 794-796
Abstract:
Two new eremophilane sesquiterpenes, 3β-angeloyloxy-8-oxo-eremophil-6(7)-en-12-oic acid 1 and 3β-angeloyloxy-10β-hydroxy-8-oxo-eremophil-6(7)-en-12-oic acid 2, and a novel nor-eremophilane derivative, 3β-angeloyloxy-10β-hydroxy-8-oxo-eremophil-6(7)-en 3 were iso-lated from the roots of Cacalia ainsliaeflora. Their structures were elucidated by spectroscopic methods, including 2D NMR.
Two new eremophilane sesquiterpenes, 3β-angeloyloxy-8-oxo-eremophil-6(7)-en-12-oic acid 1 and 3β-angeloyloxy-10β-hydroxy-8-oxo-eremophil-6(7)-en-12-oic acid 2, and a novel nor-eremophilane derivative, 3β-angeloyloxy-10β-hydroxy-8-oxo-eremophil-6(7)-en 3 were iso-lated from the roots of Cacalia ainsliaeflora. Their structures were elucidated by spectroscopic methods, including 2D NMR.
2004, 15(7): 797-800
Abstract:
From the dried aerial part of Parepigynum funingesis Tsiang et P. T. Li (Apocynaceae), a new cardiac glucoside, named parefuningoside (1) had been isolated. Its structure was determined by means of hydrolysis and spectral analysis.
From the dried aerial part of Parepigynum funingesis Tsiang et P. T. Li (Apocynaceae), a new cardiac glucoside, named parefuningoside (1) had been isolated. Its structure was determined by means of hydrolysis and spectral analysis.
2004, 15(7): 801-804
Abstract:
The reaction of nitrosonium (NO+) with Schiff bases produced diazonium salts and aldehydes in good yield. The reaction is assumed to be an electrophilic reaction of nitrosonium with imines via a four-member ring intermediate
The reaction of nitrosonium (NO+) with Schiff bases produced diazonium salts and aldehydes in good yield. The reaction is assumed to be an electrophilic reaction of nitrosonium with imines via a four-member ring intermediate
2004, 15(7): 805-807
Abstract:
The multi-walled carbon nanotubes (MWNTs) electrode was constructed using poly-tetrafluoroethylene as binder, and the electrochemical reductive behavior of oxygen in alkaline solution was first examined on this electrode. Compared with other carbon materials, MWNTs show higher electrocatalytic activity, and the reversibility of O2 reduction reaction is greatly improved. The experiments reveal that the electrochemical reduction of O2 to HO2- is controlled by adsorption. The preliminary results illustrate the potential application of MWNTs in fuel cells.
The multi-walled carbon nanotubes (MWNTs) electrode was constructed using poly-tetrafluoroethylene as binder, and the electrochemical reductive behavior of oxygen in alkaline solution was first examined on this electrode. Compared with other carbon materials, MWNTs show higher electrocatalytic activity, and the reversibility of O2 reduction reaction is greatly improved. The experiments reveal that the electrochemical reduction of O2 to HO2- is controlled by adsorption. The preliminary results illustrate the potential application of MWNTs in fuel cells.
2004, 15(7): 808-810
Abstract:
A series of N-alkyl or N-aryl chitosan quaternary ammonium salt were prepared using 96% deacetylated chitosan. Their scavenging activities against superoxide anion radical were investigated by chemiluminescence. The IC50 values of these compounds range from 280 to 880 μg/mL, which should be attributed to their different substitutes.
A series of N-alkyl or N-aryl chitosan quaternary ammonium salt were prepared using 96% deacetylated chitosan. Their scavenging activities against superoxide anion radical were investigated by chemiluminescence. The IC50 values of these compounds range from 280 to 880 μg/mL, which should be attributed to their different substitutes.
2004, 15(7): 811-812
Abstract:
Polysaccharide produced by mutated strain of Streptococcus zooepidemicus was purified by the procedures including Savage method, quaternary ammonium compound precipitation, DEAE-cellulose(DE52) chromatography and Sephadex G-75 gel filtration. The structure of the purified polysaccharide has been characterized by means of chemical composition analysis, 13C NMR spectrum, infrared spectrum and circular dichroism (CD). All the results showed that the purified polysaccharide was hyaluronic acid (HA). The single helix conformation of the purified HA was determined by Congo red experiment. The molecular weight of the HA was about 1.16×106D, which was measured by viscosity method.
Polysaccharide produced by mutated strain of Streptococcus zooepidemicus was purified by the procedures including Savage method, quaternary ammonium compound precipitation, DEAE-cellulose(DE52) chromatography and Sephadex G-75 gel filtration. The structure of the purified polysaccharide has been characterized by means of chemical composition analysis, 13C NMR spectrum, infrared spectrum and circular dichroism (CD). All the results showed that the purified polysaccharide was hyaluronic acid (HA). The single helix conformation of the purified HA was determined by Congo red experiment. The molecular weight of the HA was about 1.16×106D, which was measured by viscosity method.
2004, 15(7): 813-816
Abstract:
It is reported that the direct electron transfer of hemoglobin (Hb) can be effectively promoted by carbon nanotubes when Hb was immobilized on the surface of the carbon nanotubes modified electrode. The results indicated that the conversion of Hb-Fe(Ⅲ)/Hb-Fe(Ⅱ) is a one-electron coupled one-proton reaction process. The method presented can be easily extended to study the direct electrochemistry of other proteins or enzymes.
It is reported that the direct electron transfer of hemoglobin (Hb) can be effectively promoted by carbon nanotubes when Hb was immobilized on the surface of the carbon nanotubes modified electrode. The results indicated that the conversion of Hb-Fe(Ⅲ)/Hb-Fe(Ⅱ) is a one-electron coupled one-proton reaction process. The method presented can be easily extended to study the direct electrochemistry of other proteins or enzymes.
2004, 15(7): 817-820
Abstract:
Hydrolysis procedure of N-phosphoryl phenylalanine (DIPP-Phe) was studied by HPLC-ESI-MS/MS. The results showed that (HO)(i-PrO)P(O)Phe was the main intermediate and the hydrolysis of DIPP-Phe also occurred through a penta-coordinate transition state.
Hydrolysis procedure of N-phosphoryl phenylalanine (DIPP-Phe) was studied by HPLC-ESI-MS/MS. The results showed that (HO)(i-PrO)P(O)Phe was the main intermediate and the hydrolysis of DIPP-Phe also occurred through a penta-coordinate transition state.
2004, 15(7): 821-822
Abstract:
The electrooxidation of tetracycline (TC) at acetylene black electrode has been studied in the presence of sodium dodecyl sulfate (SDS). Tetracycline (TC) exhibited very sensitive oxidation peak in this system. The peak current was proportional to TC concentration, and the detection limit was 1.2×10-8 mol/L. The system was used to the determination of TC in pharmaceuticals.
The electrooxidation of tetracycline (TC) at acetylene black electrode has been studied in the presence of sodium dodecyl sulfate (SDS). Tetracycline (TC) exhibited very sensitive oxidation peak in this system. The peak current was proportional to TC concentration, and the detection limit was 1.2×10-8 mol/L. The system was used to the determination of TC in pharmaceuticals.
2004, 15(7): 823-826
Abstract:
Mass spectrometer is connected through an adaptor to a sealed small battery to probe the gas phase changes inside the battery. The factors influencing the response time are analyzed with a simplified model. The feasibility of the new technique is demonstrated with a Ni-Cd battery, showing different profiles of MS intensities for O2 and H2. Compared with gas chromatography, this technique has the advantage of being noninvasive and should be useful for the study and diagnostic examination of small sealed batteries.
Mass spectrometer is connected through an adaptor to a sealed small battery to probe the gas phase changes inside the battery. The factors influencing the response time are analyzed with a simplified model. The feasibility of the new technique is demonstrated with a Ni-Cd battery, showing different profiles of MS intensities for O2 and H2. Compared with gas chromatography, this technique has the advantage of being noninvasive and should be useful for the study and diagnostic examination of small sealed batteries.
2004, 15(7): 827-830
Abstract:
Interfacial proton transfer reactions of pure mercaptoacetic acid (MA) and 2-mercaptobenzothiazole (Mbz) mixed self-assembled monolayers (SAMs) have been studied using a.c. impedance titration method. The charge-transfer resistance (Rct) is measured with the monolayer composition and the ionic strength of pH solution. The surface pKa can be obtained by the plots of Rct and pH, the reasons of shifts of surface pKa are also explained.
Interfacial proton transfer reactions of pure mercaptoacetic acid (MA) and 2-mercaptobenzothiazole (Mbz) mixed self-assembled monolayers (SAMs) have been studied using a.c. impedance titration method. The charge-transfer resistance (Rct) is measured with the monolayer composition and the ionic strength of pH solution. The surface pKa can be obtained by the plots of Rct and pH, the reasons of shifts of surface pKa are also explained.
2004, 15(7): 831-833
Abstract:
A new MEEKC method assisted with pressure-driven mobile phase was presented for the separation of felted explosives. Microemulsion solution was composed of 80 mmol/L heptane-120 mmol/L SDS (sodium dodecyl sulphate)-900 mmol/L butanol-10 mmol/L borate at pH 9.4 and a pressure-driven flow of 0.020 mL/min under 1.3 MPa was employed to manipulate the separation. Explosives HMX (1, 3, 5, 7-tetranitro-1, 3, 5, 7-tetrazacyclooctane) and TATB (triamino-trinitrobenzene), which were felted on fluorine rubber F2311(polytrifluorochlorethylene and polyvinylidene fluoride 1/1 co-polymerization)and F2314(polytrifluorochlorethylene and polyvinylidene fluoride 4/1 co-polymerization)were well separated with very good peak shapes.
A new MEEKC method assisted with pressure-driven mobile phase was presented for the separation of felted explosives. Microemulsion solution was composed of 80 mmol/L heptane-120 mmol/L SDS (sodium dodecyl sulphate)-900 mmol/L butanol-10 mmol/L borate at pH 9.4 and a pressure-driven flow of 0.020 mL/min under 1.3 MPa was employed to manipulate the separation. Explosives HMX (1, 3, 5, 7-tetranitro-1, 3, 5, 7-tetrazacyclooctane) and TATB (triamino-trinitrobenzene), which were felted on fluorine rubber F2311(polytrifluorochlorethylene and polyvinylidene fluoride 1/1 co-polymerization)and F2314(polytrifluorochlorethylene and polyvinylidene fluoride 4/1 co-polymerization)were well separated with very good peak shapes.
2004, 15(7): 834-836
Abstract:
Bowl-like poly (styrene-co-glycidyl methacrylate) was synthesized by swollen seeded emulsion polymerization. The polymerization was carried out in PS seed emulsion swollen by toluene, whereby the bowl-like particles formed at last. The shape was observed by SEM. These particles became ball-like when swollen by toluene, observed by optical microscope, and the release behavior of solvent from them was examined.
Bowl-like poly (styrene-co-glycidyl methacrylate) was synthesized by swollen seeded emulsion polymerization. The polymerization was carried out in PS seed emulsion swollen by toluene, whereby the bowl-like particles formed at last. The shape was observed by SEM. These particles became ball-like when swollen by toluene, observed by optical microscope, and the release behavior of solvent from them was examined.
2004, 15(7): 837-840
Abstract:
A novel substrate for in situ synthesis of oligonucleotide was prepared by hydrolyzing microporous polyamide-6 membranes in a 0.01mol/L NaOH/(H2O-CH3OH) mixture medium. The formation of amines (NH2) on the surface was proved by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The treated membrane was applied for in situ synthesis of oligonucleotide and a single step coupling efficiency determined by ultraviolet (UV) spectra was above 98%.
A novel substrate for in situ synthesis of oligonucleotide was prepared by hydrolyzing microporous polyamide-6 membranes in a 0.01mol/L NaOH/(H2O-CH3OH) mixture medium. The formation of amines (NH2) on the surface was proved by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The treated membrane was applied for in situ synthesis of oligonucleotide and a single step coupling efficiency determined by ultraviolet (UV) spectra was above 98%.
2004, 15(7): 841-844
Abstract:
In this paper, a set of ultrasonic vibration device connecting with small angle light scattering(SALS) for in-situ observing phase-transition of polymer under ultrasonic vibration was established. The experiments for verifying polypropylene(PP) indicated that ultrasonic vibration resulted in the decrease of the crystallization rate and made PP crystallizable at low temperature.
In this paper, a set of ultrasonic vibration device connecting with small angle light scattering(SALS) for in-situ observing phase-transition of polymer under ultrasonic vibration was established. The experiments for verifying polypropylene(PP) indicated that ultrasonic vibration resulted in the decrease of the crystallization rate and made PP crystallizable at low temperature.
2004, 15(7): 845-848
Abstract:
Thickness and stability of films formed by different surfactants are studied by means of thin film balance (TFB) technique to observe the formation and stability of the films. It is demonstrated that stable Newton black films (NBFs) can be easily obtained with non-ionic surfactants (C12E5, C12G2) than ionic surfactants (C12TAB, C16TAB). Common black film (CBF) was obtained with C16TAB at 5×10-3 mol/L, while the film of C12TAB is unstable. It has been demonstrated that the horizontal forces should also be taken into consideration for explaining film stability.
Thickness and stability of films formed by different surfactants are studied by means of thin film balance (TFB) technique to observe the formation and stability of the films. It is demonstrated that stable Newton black films (NBFs) can be easily obtained with non-ionic surfactants (C12E5, C12G2) than ionic surfactants (C12TAB, C16TAB). Common black film (CBF) was obtained with C16TAB at 5×10-3 mol/L, while the film of C12TAB is unstable. It has been demonstrated that the horizontal forces should also be taken into consideration for explaining film stability.
2004, 15(7): 849-852
Abstract:
A novel poly-l-arginine microcapsule was prepared due to its nutritional function and pharmacological efficacy. A high-voltage electrostatic droplet generator was used to make uniform microcapsules. The results show that the membrane strength and permeating property are both remarkably affected with the changes of sodium alginate concentration. With the sodium alginate concentration increasing, gel beads sizes increase from 233μm to 350μm, release ratio is also higher at the same time, but the membrane strength decreases.
A novel poly-l-arginine microcapsule was prepared due to its nutritional function and pharmacological efficacy. A high-voltage electrostatic droplet generator was used to make uniform microcapsules. The results show that the membrane strength and permeating property are both remarkably affected with the changes of sodium alginate concentration. With the sodium alginate concentration increasing, gel beads sizes increase from 233μm to 350μm, release ratio is also higher at the same time, but the membrane strength decreases.
2004, 15(7): 853-855
Abstract:
The B-typed starch spherocrystals were prepared by the dissolution and freezing crystallization of acid-hydrolyzed starch obtained by the mild hydrolysis of maize starch. The spherocrystals were characterized with scanning electron microscope (SEM), X-ray diffraction, thermogravimetry (TG) and gel pervasion chromatogram (GPC). The results show that the preparation was a B-type spherocrystal with the average degree of polymerization of 14 glucose units, and the average diameter of crystal particles was about 7μm.
The B-typed starch spherocrystals were prepared by the dissolution and freezing crystallization of acid-hydrolyzed starch obtained by the mild hydrolysis of maize starch. The spherocrystals were characterized with scanning electron microscope (SEM), X-ray diffraction, thermogravimetry (TG) and gel pervasion chromatogram (GPC). The results show that the preparation was a B-type spherocrystal with the average degree of polymerization of 14 glucose units, and the average diameter of crystal particles was about 7μm.
2004, 15(7): 856-858
Abstract:
In this paper, a new silica-supported poly-γ-aminopropylsilane Cu2+-Pd2+ complex was studied in Heck vinylation reaction of aryl iodide with olefins. The catalyst is highly active and stereoselective at 70-100℃, and can be resused after washing without loss in activity.
In this paper, a new silica-supported poly-γ-aminopropylsilane Cu2+-Pd2+ complex was studied in Heck vinylation reaction of aryl iodide with olefins. The catalyst is highly active and stereoselective at 70-100℃, and can be resused after washing without loss in activity.
2004, 15(7): 859-862
Abstract:
A novel vanadate decamer, involving all vanadium atoms present in +5 oxidation and one formhydroxamic acid dimer cation readical, has been synthesized. The single-crystal X-ray diffraction shows that the orange crystal is formed in the triclinic system, space group Pī, a=8.4960 (17), b=10.447 (2), c=11.299 (2)Å, α=68.82 (3)°,β=87.35 (3)°, γ=66.97 (3)°. V=855.3(3)Å3, Z=8, R1=0.0857, wR2=0.2551. X-ray crystallographic and packing in superlattice studies showed that the crystal structure was constructed by electrostatic attraction of O-H…O hydrogen bonds between formhydroxamic acid dimer cation and decavanadate polyanion. Formhydroxamic acid dimer is got through controlling the condition of the reaction using formhydroxamic acid.
A novel vanadate decamer, involving all vanadium atoms present in +5 oxidation and one formhydroxamic acid dimer cation readical, has been synthesized. The single-crystal X-ray diffraction shows that the orange crystal is formed in the triclinic system, space group Pī, a=8.4960 (17), b=10.447 (2), c=11.299 (2)Å, α=68.82 (3)°,β=87.35 (3)°, γ=66.97 (3)°. V=855.3(3)Å3, Z=8, R1=0.0857, wR2=0.2551. X-ray crystallographic and packing in superlattice studies showed that the crystal structure was constructed by electrostatic attraction of O-H…O hydrogen bonds between formhydroxamic acid dimer cation and decavanadate polyanion. Formhydroxamic acid dimer is got through controlling the condition of the reaction using formhydroxamic acid.
2004, 15(7): 863-866
Abstract:
A novel borophosphate (Hmel)3{Co2[(mel)2(HPO4)2(PO4)]·(H3BO3·H2O} (mel=melamine) has been synthesized under mild solvothermal conditions. The structure of the compound exists a high ordered organic-inorganic sandwich-type supramolecular architecture via metal-coordination, hydrogen bonds and π-π stacking interactions.
A novel borophosphate (Hmel)3{Co2[(mel)2(HPO4)2(PO4)]·(H3BO3·H2O} (mel=melamine) has been synthesized under mild solvothermal conditions. The structure of the compound exists a high ordered organic-inorganic sandwich-type supramolecular architecture via metal-coordination, hydrogen bonds and π-π stacking interactions.
2004, 15(7): 867-870
Abstract:
Using nanocrystalline[Mg-Al-CO3] and[Zn-Al-CO3] as precursors,[Mg-Al-PO4],[Zn-Al-PO4],[Mg-Al-P2O7] and[Zn-Al-P2O7] have been successfully synthesized by a direct reaction with the free PO43- or P2O74- using the microwave techniques and the anion-exchange method. And the samples thus obtained were characterized by TEM, FT-IR and XRD. The results show that the initial interlayer carbonate ions can be completely replaced by the free PO43- or P2O74- under controlled microwave conditions employed for a short time.
Using nanocrystalline[Mg-Al-CO3] and[Zn-Al-CO3] as precursors,[Mg-Al-PO4],[Zn-Al-PO4],[Mg-Al-P2O7] and[Zn-Al-P2O7] have been successfully synthesized by a direct reaction with the free PO43- or P2O74- using the microwave techniques and the anion-exchange method. And the samples thus obtained were characterized by TEM, FT-IR and XRD. The results show that the initial interlayer carbonate ions can be completely replaced by the free PO43- or P2O74- under controlled microwave conditions employed for a short time.
2004, 15(7): 871-874
Abstract:
Zirconium proline-N-methylphosphonate-phosphate (α-ZPMPP) was prepared in the presence of HF for the first time. The α-ZPMPP sample is highly crystallized with interlayer distance of 1.52 nm. The interlayer distance of complex of α-ZPMPP with n-butylamine (α-ZPMPP-BA) is in 0.45 nm larger than that of α-ZPMPP. The α-ZPMPP possesses different intercalation behavior of host-guest compound from α-ZP.
Zirconium proline-N-methylphosphonate-phosphate (α-ZPMPP) was prepared in the presence of HF for the first time. The α-ZPMPP sample is highly crystallized with interlayer distance of 1.52 nm. The interlayer distance of complex of α-ZPMPP with n-butylamine (α-ZPMPP-BA) is in 0.45 nm larger than that of α-ZPMPP. The α-ZPMPP possesses different intercalation behavior of host-guest compound from α-ZP.
2004, 15(7): 875-878
Abstract:
It is reported for the first time that the Pt/C catalyst can be prepared with a new and simple organic sol method using SnCl2 as the reductant. It was found that the average size of the Pt particles in the Pt/C catalysts could be controlled with controlling the preparation conditions. The effect of the average sizes of the Pt particles in the Pt/C catalysts obtained with this method on the electrocatalytical activity of the oxidation of methanol was investigated.
It is reported for the first time that the Pt/C catalyst can be prepared with a new and simple organic sol method using SnCl2 as the reductant. It was found that the average size of the Pt particles in the Pt/C catalysts could be controlled with controlling the preparation conditions. The effect of the average sizes of the Pt particles in the Pt/C catalysts obtained with this method on the electrocatalytical activity of the oxidation of methanol was investigated.
2004, 15(7): 879-882
Abstract:
The diffusivity and viscosity of water confined in micropores were studied by molecular dynamics simulations. The effects of pore width and density were analyzed at pore widths from 0.9 to 2.6 nm. The diffusivity in micropores is lower than that of the bulk, and it decreases as pore width decreases and as density increases. But the viscosity in micropores is much larger than that of the bulk, and it increases as pore width decreases and as density increases. The diffusivity in channel parallel direction is obviously larger than that in channel perpendicular directions.
The diffusivity and viscosity of water confined in micropores were studied by molecular dynamics simulations. The effects of pore width and density were analyzed at pore widths from 0.9 to 2.6 nm. The diffusivity in micropores is lower than that of the bulk, and it decreases as pore width decreases and as density increases. But the viscosity in micropores is much larger than that of the bulk, and it increases as pore width decreases and as density increases. The diffusivity in channel parallel direction is obviously larger than that in channel perpendicular directions.
