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1999 Volume 10 Issue 3
1999, 10(3): 189-190
Abstract:
A new method was found for the synthesis of pyrazoleacetate esters from pyrazolaldehyde.By a new tandem reaction.in which methyl 4-pyrazoleacetate reacted with carbon disulfide andiodomethane.thieno [2.3-c] pyrazole was synthesized.This was an easy method for the synthesis of this type of heterocyeles.
A new method was found for the synthesis of pyrazoleacetate esters from pyrazolaldehyde.By a new tandem reaction.in which methyl 4-pyrazoleacetate reacted with carbon disulfide andiodomethane.thieno [2.3-c] pyrazole was synthesized.This was an easy method for the synthesis of this type of heterocyeles.
1999, 10(3): 191-192
Abstract:
The title compounds of 3-aryl-5-cyano-6-methylthiopyrimidine2.4-diones weresynthesized by the reaction of ethy1 2-cyano-3.3'dimethylthioacrylate with arylureas.The compound (Ar=p-CH3OC6H4) was recrystallized in acetone/petroleum in space group P2(1/n) with a=1.1602 (2), b=1.5921(3), c=1.3918 (3)nm.β=94.38 (3)° for Z=8.R=0.054.The X-ray analysis showed that there is H-bond interaction among molecules.
The title compounds of 3-aryl-5-cyano-6-methylthiopyrimidine2.4-diones weresynthesized by the reaction of ethy1 2-cyano-3.3'dimethylthioacrylate with arylureas.The compound (Ar=p-CH3OC6H4) was recrystallized in acetone/petroleum in space group P2(1/n) with a=1.1602 (2), b=1.5921(3), c=1.3918 (3)nm.β=94.38 (3)° for Z=8.R=0.054.The X-ray analysis showed that there is H-bond interaction among molecules.
1999, 10(3): 193-194
Abstract:
Calix [4] pyrroles.as a class of new molecular receptor in the area of supramolecular chemistry.have displayed interesting anion and neutral substrate binding properties.In this paper.several new calix [4] pyrrole macrocycles were synthesised and characterized.
Calix [4] pyrroles.as a class of new molecular receptor in the area of supramolecular chemistry.have displayed interesting anion and neutral substrate binding properties.In this paper.several new calix [4] pyrrole macrocycles were synthesised and characterized.
1999, 10(3): 195-198
Abstract:
Protected (I.) and (D)-lysune wore used respectively as starting materials to synthesize two new types of chiral blocks for the construction of PNA.Nucleobasc was linked to α-NH2 of lysine via -CH2C (O)- spacer in type 1.and -C (O)- was used in type Ⅱ.The corresponding oligomers were constructed in solution.
Protected (I.) and (D)-lysune wore used respectively as starting materials to synthesize two new types of chiral blocks for the construction of PNA.Nucleobasc was linked to α-NH2 of lysine via -CH2C (O)- spacer in type 1.and -C (O)- was used in type Ⅱ.The corresponding oligomers were constructed in solution.
1999, 10(3): 199-200
Abstract:
(2R,4S,5S)-(+)-threo-5-(2,2-dichloroacetamido)-4-(4-nitrophenyl)-2-aryl-l,3-dioxanes, were synthesized with high diastereoselectivity and good yields.The structures of acetals were determined and the configurations were confirmed by 2D-NMR (NOESY).
(2R,4S,5S)-(+)-threo-5-(2,2-dichloroacetamido)-4-(4-nitrophenyl)-2-aryl-l,3-dioxanes, were synthesized with high diastereoselectivity and good yields.The structures of acetals were determined and the configurations were confirmed by 2D-NMR (NOESY).
1999, 10(3): 201-204
Abstract:
(3R, 9S.lOS)-Heptadec-l-ene-4,6-diyne-3.9.10-triol 2.a diastereoisomer of panaxytriol 1 was synthesized using L-(+)-diethyl tartrate 5 as a chiral template.through the Cadiot-Chodkiczwicz coupling of the terminal acetylene 3 with bromoacetylene 4.
(3R, 9S.lOS)-Heptadec-l-ene-4,6-diyne-3.9.10-triol 2.a diastereoisomer of panaxytriol 1 was synthesized using L-(+)-diethyl tartrate 5 as a chiral template.through the Cadiot-Chodkiczwicz coupling of the terminal acetylene 3 with bromoacetylene 4.
1999, 10(3): 205-206
Abstract:
The first aliphatic phosphenium cation featuring a P-S bond (dimethylamino) (methylthio) phosphenium cation 1.has been prepared by treatument of the (dimethylamino) (methylthio) chlorophosphines 2 wih the stoichiometri quantity of AlCl3 in CH2Cl2 solution, and characterized by 1H 13C 27Al and 31P NMR spectroscopy.
The first aliphatic phosphenium cation featuring a P-S bond (dimethylamino) (methylthio) phosphenium cation 1.has been prepared by treatument of the (dimethylamino) (methylthio) chlorophosphines 2 wih the stoichiometri quantity of AlCl3 in CH2Cl2 solution, and characterized by 1H 13C 27Al and 31P NMR spectroscopy.
1999, 10(3): 207-208
Abstract:
The properties of nonadiabatic trapping models of the reaction NH+H -N+H2 are investigated in a collinear model as well as a non-collinear thermal reaction on the basis of the intrinsic reaction coordinate (IRC) information obtained by ab initio calculations at QCISD/631IG** level.Using the unified statistical theory fornonadiabatic trapping models.the thermal rate constants over the temperature range of 2000-3000K are computed which are in excellent agreement with the experiment results.
The properties of nonadiabatic trapping models of the reaction NH+H -N+H2 are investigated in a collinear model as well as a non-collinear thermal reaction on the basis of the intrinsic reaction coordinate (IRC) information obtained by ab initio calculations at QCISD/631IG** level.Using the unified statistical theory fornonadiabatic trapping models.the thermal rate constants over the temperature range of 2000-3000K are computed which are in excellent agreement with the experiment results.
1999, 10(3): 209-212
Abstract:
Coordination behavior of bidentate ligand ethylenediamine with a new chiral zinc bisporphyrin O.O-C2-AA-C2-(TPP)2 Zn2 was investigated by Uv-Vis titration and 1H-NMR spectroscopy.which further evidenced that O.O-C2-AA-C2-(TPP)2Zn2, tends to form linear assembly with ethylenediamine in chloroform.
Coordination behavior of bidentate ligand ethylenediamine with a new chiral zinc bisporphyrin O.O-C2-AA-C2-(TPP)2 Zn2 was investigated by Uv-Vis titration and 1H-NMR spectroscopy.which further evidenced that O.O-C2-AA-C2-(TPP)2Zn2, tends to form linear assembly with ethylenediamine in chloroform.
1999, 10(3): 213-214
Abstract:
Optical stability of chiral 2-methylbutyric acid in gas phase has been detected with Quadrupole-Quistor-Quadrupole tandem mass spectrometer in combination with deuteration.The results show that these compounds are optically unstable in the process of self chemical ionization.
Optical stability of chiral 2-methylbutyric acid in gas phase has been detected with Quadrupole-Quistor-Quadrupole tandem mass spectrometer in combination with deuteration.The results show that these compounds are optically unstable in the process of self chemical ionization.
1999, 10(3): 215-218
Abstract:
Macroporous poly [ (chloromethyl) styrene-co-divinylbenzene] continuous rod was prepared by direct polymerization of the monomers in the presence of a porogenic diluent inside an empty chromatographic column.A new "in-situ" technique was used to modify the synthesized polymer rod for a weak canon exchanger and it has been used successfully for the separation of biopolymers.It was found that the back pressure of the continuous rod column was much lower and its surface was proved to be modified well.
Macroporous poly [ (chloromethyl) styrene-co-divinylbenzene] continuous rod was prepared by direct polymerization of the monomers in the presence of a porogenic diluent inside an empty chromatographic column.A new "in-situ" technique was used to modify the synthesized polymer rod for a weak canon exchanger and it has been used successfully for the separation of biopolymers.It was found that the back pressure of the continuous rod column was much lower and its surface was proved to be modified well.
1999, 10(3): 219-222
Abstract:
The separation efficiency of biopolymers with a short column in liquid chromatography has been investigated in this paper.It was found that the column length has slight effect on the resolution of biopolymers under gradient elution.The reasons have been explained by stoichiometric displacement model for retention of solute.The column 1 .0 cm long was also used in the separation and purification of recombinant human granulocyte colony-simulating factor (rhG-CSF).It only took 40 min and the purity by one step was found to be almost 100%.
The separation efficiency of biopolymers with a short column in liquid chromatography has been investigated in this paper.It was found that the column length has slight effect on the resolution of biopolymers under gradient elution.The reasons have been explained by stoichiometric displacement model for retention of solute.The column 1 .0 cm long was also used in the separation and purification of recombinant human granulocyte colony-simulating factor (rhG-CSF).It only took 40 min and the purity by one step was found to be almost 100%.
1999, 10(3): 223-226
Abstract:
Fused－silical capillary columns containing heptakis (2、3、6－tri－o－pentyl)-β-cyclodextrin and dibenzo-18-crown-6 were prepared.By studying the selectivity of mixed stationary phases for some solute pairs.as well as comparing with the heptakis (2、3、6-tri-O-pentyl)-β-cyclodextrin and thedibenzo-18-crown-6 used as individual stationary phase、the synergistic effects were observed.These effects were affected by the column temperature.mixed ratio and linear velocity of carrier gas.
Fused－silical capillary columns containing heptakis (2、3、6－tri－o－pentyl)-β-cyclodextrin and dibenzo-18-crown-6 were prepared.By studying the selectivity of mixed stationary phases for some solute pairs.as well as comparing with the heptakis (2、3、6-tri-O-pentyl)-β-cyclodextrin and thedibenzo-18-crown-6 used as individual stationary phase、the synergistic effects were observed.These effects were affected by the column temperature.mixed ratio and linear velocity of carrier gas.
1999, 10(3): 227-230
Abstract:
Either triethylamine or diethylenetriamine can be conveniently used as a dynamic modifier to suppress the adsorption of basic proteins in capillary zone electrophoresis.Sufficiently high column efficiencies (>2×105 plates/m for cytochrome C) were obtained with either of them along with the improvement of the peak shapes and repeatability of migration time.The relationship between the adsorption suppression effect of the modifier and its structure was discussed.
Either triethylamine or diethylenetriamine can be conveniently used as a dynamic modifier to suppress the adsorption of basic proteins in capillary zone electrophoresis.Sufficiently high column efficiencies (>2×105 plates/m for cytochrome C) were obtained with either of them along with the improvement of the peak shapes and repeatability of migration time.The relationship between the adsorption suppression effect of the modifier and its structure was discussed.
1999, 10(3): 231-234
Abstract:
A new capillary electrophoresis apparatus was designed.Piezoelectric ceramics transformer technology was first applied in capillary electrophoresis.a high voltage and stable source was made.Amperometric detector was used in which the working electrode was closely opposite to the end of capillary.The apparatus was characterized in good reproducibility safety and very low cost.
A new capillary electrophoresis apparatus was designed.Piezoelectric ceramics transformer technology was first applied in capillary electrophoresis.a high voltage and stable source was made.Amperometric detector was used in which the working electrode was closely opposite to the end of capillary.The apparatus was characterized in good reproducibility safety and very low cost.
1999, 10(3): 235-238
Abstract:
A novel capillary electrophoresis method coupled with on-line microdialysis using an attachable electrode has been developed to study the interaction of macromolecule with small molecule.The binding constants of bovine serum album (BSA) with D.L-tryptophan (Trp), sulfamethoxazole (SMZ) with trypsin and chymotrypsin were determined.These values are 2.3×104L/mol for BSA-L-Trp.1.77×103 L/mol for BSA-D-TrP in PH 7.4, 50 mmol/ L phosphate; 1.4×104 L/mol for SMZ-trypsin and 6.0×103 L/mol for SMZ-chymotrypsin in PH 6.5, 25 mmol/L Tris buffer.The proposed method has merits of speed.low sample consumption and readily available to be performed in desired physiological conditions.
A novel capillary electrophoresis method coupled with on-line microdialysis using an attachable electrode has been developed to study the interaction of macromolecule with small molecule.The binding constants of bovine serum album (BSA) with D.L-tryptophan (Trp), sulfamethoxazole (SMZ) with trypsin and chymotrypsin were determined.These values are 2.3×104L/mol for BSA-L-Trp.1.77×103 L/mol for BSA-D-TrP in PH 7.4, 50 mmol/ L phosphate; 1.4×104 L/mol for SMZ-trypsin and 6.0×103 L/mol for SMZ-chymotrypsin in PH 6.5, 25 mmol/L Tris buffer.The proposed method has merits of speed.low sample consumption and readily available to be performed in desired physiological conditions.
1999, 10(3): 239-242
Abstract:
Different hydrolysis and extraction procedures have been studied for the determination of drugs of abuse in hair samples.The results showed that acid and enzymatic hydrolysis gave high extraction recoveries for 6-monoacetylmorphine.morphine.codeine and heroin.Enzymatic hydrolysis was more expensive.After alkaline hydrolysis.6-monoacetylmorphine.a unique proof of heroin abuse.could not be detected and after methanolic extraction.the extract was dirty and the obtained chromatogram showed an interfering background.It is concluded that acid hydrolysis is the extraction method of choice.
Different hydrolysis and extraction procedures have been studied for the determination of drugs of abuse in hair samples.The results showed that acid and enzymatic hydrolysis gave high extraction recoveries for 6-monoacetylmorphine.morphine.codeine and heroin.Enzymatic hydrolysis was more expensive.After alkaline hydrolysis.6-monoacetylmorphine.a unique proof of heroin abuse.could not be detected and after methanolic extraction.the extract was dirty and the obtained chromatogram showed an interfering background.It is concluded that acid hydrolysis is the extraction method of choice.
1999, 10(3): 243-246
Abstract:
The basal levels of magnesium and copper in rat brain and flowering plum fruit dialysates.and the background concentration of calcium in pea dialysates have been determined with sensitive spectroscopic techniques including atomic absorption spectrometry and spectrophotometry based on amino G acid chlorophosphonazo.It is found that the magnesium level in flowering plum fruit dialysates is much lower than that in rat brain dialysates.indicating a considerable composition difference present between a plant dialysate and an animal one.
The basal levels of magnesium and copper in rat brain and flowering plum fruit dialysates.and the background concentration of calcium in pea dialysates have been determined with sensitive spectroscopic techniques including atomic absorption spectrometry and spectrophotometry based on amino G acid chlorophosphonazo.It is found that the magnesium level in flowering plum fruit dialysates is much lower than that in rat brain dialysates.indicating a considerable composition difference present between a plant dialysate and an animal one.
1999, 10(3): 247-250
Abstract:
A PCV-modified electrode was simply prepared by dip-coating a pyrolytic graphite electrode in a NaAc-HAc buffer solution of PCV.The peak currents of differential pulse voltammograms (DPV) decrease with the addition of Al and the peak potentials remain the same.The decreasing of △ip, is linear with Al concentration in the range of 1×10-8~ 1×10-7 mol/L.The detection limit is 5 ×10-9 mol/L and the relative standard deviation for 4×10-8 mol/L Al is 2.9% (n=8).No serious interference was found.The determination of Al in water samples is reported.
A PCV-modified electrode was simply prepared by dip-coating a pyrolytic graphite electrode in a NaAc-HAc buffer solution of PCV.The peak currents of differential pulse voltammograms (DPV) decrease with the addition of Al and the peak potentials remain the same.The decreasing of △ip, is linear with Al concentration in the range of 1×10-8~ 1×10-7 mol/L.The detection limit is 5 ×10-9 mol/L and the relative standard deviation for 4×10-8 mol/L Al is 2.9% (n=8).No serious interference was found.The determination of Al in water samples is reported.
1999, 10(3): 251-254
Abstract:
A novel biferocene trinuclear complex for Schiff base ligand S-methyt-N-(ferrocenyll-methyl -methylidene) dithiocarbazate (hereafter abbreviated as HL) is described.X-ray diffraction studies established the structure of the palladium complex, PdL2.The geometry of Pd (Ⅱ) in the complex is close to square planar and in novel cis-configuration with two ferrocene moieties on the same side.Degenerate four-wave mixing (DFWM) measurements show that the complex exhibit obvious nonlinear optical response.
A novel biferocene trinuclear complex for Schiff base ligand S-methyt-N-(ferrocenyll-methyl -methylidene) dithiocarbazate (hereafter abbreviated as HL) is described.X-ray diffraction studies established the structure of the palladium complex, PdL2.The geometry of Pd (Ⅱ) in the complex is close to square planar and in novel cis-configuration with two ferrocene moieties on the same side.Degenerate four-wave mixing (DFWM) measurements show that the complex exhibit obvious nonlinear optical response.
1999, 10(3): 255-256
Abstract:
A new ECL-active species.Ru (phen)2 (dcbpy) (PF6)2.has been designed and synthesized.Its structure was confirmed by means of IR.ESI-MS and 2D NMR.Also.its properties of electrochemistry.fluorescence and ECL are reported.which have suggested a good hope of being used in electrochemiluminescent immunoassay and nucleic acid hybridization.
A new ECL-active species.Ru (phen)2 (dcbpy) (PF6)2.has been designed and synthesized.Its structure was confirmed by means of IR.ESI-MS and 2D NMR.Also.its properties of electrochemistry.fluorescence and ECL are reported.which have suggested a good hope of being used in electrochemiluminescent immunoassay and nucleic acid hybridization.
1999, 10(3): 257-260
Abstract:
The title copound Manganese Mercury Tetrathiocyanate (MnHg (SCN)4) has been synthesized and its structure has been determined.It belongs to tetragonal system, 4 space group.The cell dimensions are:a=1.1324 (3)nm, c=0.4270 (2) nm.V=0.5475 (3)nm3, Z=2, Dc= 2.959 g/cm3, R=0.028, Rw = 0.037.The structure feature of the crystal is the Hg-S-C N-Mn bridge which leads to the formation of an infinite three dimensional network.Irradiated by a 1064 nm Nd:YAG laser beam.MnHg (SCN)4 shows a 532 nm second harmonic intensity which is 18 times as that of organic nonlinear optical crystal urea, and therefore shows a quite promising application value as a useful nonliear optical material.
The title copound Manganese Mercury Tetrathiocyanate (MnHg (SCN)4) has been synthesized and its structure has been determined.It belongs to tetragonal system, 4 space group.The cell dimensions are:a=1.1324 (3)nm, c=0.4270 (2) nm.V=0.5475 (3)nm3, Z=2, Dc= 2.959 g/cm3, R=0.028, Rw = 0.037.The structure feature of the crystal is the Hg-S-C N-Mn bridge which leads to the formation of an infinite three dimensional network.Irradiated by a 1064 nm Nd:YAG laser beam.MnHg (SCN)4 shows a 532 nm second harmonic intensity which is 18 times as that of organic nonlinear optical crystal urea, and therefore shows a quite promising application value as a useful nonliear optical material.
1999, 10(3): 261-262
Abstract:
A novel kind of multifunctional polysiloxane containing charge-transporting agent and as electro-optical chromophore has been prepared for photorefractive application.The structural characterization of this kind of polymer is presented by IR spectra and elemental analysis.
A novel kind of multifunctional polysiloxane containing charge-transporting agent and as electro-optical chromophore has been prepared for photorefractive application.The structural characterization of this kind of polymer is presented by IR spectra and elemental analysis.
1999, 10(3): 263-266
Abstract:
The title complex M (mnt) (phen), M=Fe11, Co11.Ni11, Cu11.Zn11.was respectively synthesized by reaction of disodium maleionitriledithiolate (Na2 (mnt)) with corresponding metal complex M (phen) Cl2.Charge transfer transitions in the absorption and emission spectra have been studed.
The title complex M (mnt) (phen), M=Fe11, Co11.Ni11, Cu11.Zn11.was respectively synthesized by reaction of disodium maleionitriledithiolate (Na2 (mnt)) with corresponding metal complex M (phen) Cl2.Charge transfer transitions in the absorption and emission spectra have been studed.
1999, 10(3): 267-268
Abstract:
Pure Mesoporous TiO2 molecular sieves (Ti-TMS) were synthesized with different templates for the first time and the templates can be successfully removed by refluxing the samples in the EtOH/H2O/KOH solution.The XRD pattem and TEM confirm that the uniformity and stability of Ti-TMS2 synthesized with dodecylamine as template is obviously inferior to that of TiTMS1 prepared with dodecylphosphate and hexadecylphosphate as templates.Furthermore.after the templates were removed.the mesostructure of Ti-TMS1 was preserved to a great degree than that of Ti-TMS2.
Pure Mesoporous TiO2 molecular sieves (Ti-TMS) were synthesized with different templates for the first time and the templates can be successfully removed by refluxing the samples in the EtOH/H2O/KOH solution.The XRD pattem and TEM confirm that the uniformity and stability of Ti-TMS2 synthesized with dodecylamine as template is obviously inferior to that of TiTMS1 prepared with dodecylphosphate and hexadecylphosphate as templates.Furthermore.after the templates were removed.the mesostructure of Ti-TMS1 was preserved to a great degree than that of Ti-TMS2.
