Login In
1996 Volume 7 Issue 5
1996, 7(5): 393-394
Abstract:
Ten new 1,4-disubstituted azo ureas were synthesized by the reaction of substituted semicarbazide compounds with a phenoxyl radical between two phases in good yield.
Ten new 1,4-disubstituted azo ureas were synthesized by the reaction of substituted semicarbazide compounds with a phenoxyl radical between two phases in good yield.
1996, 7(5): 397-398
Abstract:
A novel tripyrrane-containing bismacrocycle ligand was acquired by the improved procedure of the metal template 1:1 Schiff base condensation.The condensation of diformyltripyrrane <1> with 3,4,3',4'-tetraamino-biphenyl hydrochloride was modified by excluding water efficiently,then the yield was increased to over 90%.
A novel tripyrrane-containing bismacrocycle ligand was acquired by the improved procedure of the metal template 1:1 Schiff base condensation.The condensation of diformyltripyrrane <1> with 3,4,3',4'-tetraamino-biphenyl hydrochloride was modified by excluding water efficiently,then the yield was increased to over 90%.
1996, 7(5): 399-400
Abstract:
One amino acid modified phthalocyanine was synthesized and its absorption was measured.And a red shift up to 25 nm relative to ZnPc (NH2)4 was found.
One amino acid modified phthalocyanine was synthesized and its absorption was measured.And a red shift up to 25 nm relative to ZnPc (NH2)4 was found.
1996, 7(5): 401-402
Abstract:
A double-chain glycolipid,dioctadecyl-2-glucopyronosylthio-succinate (1) was synthesized.The glycolipid itself formed stable vesicles.It could also be incorporated into the lipid bilayer membrane to form stable mixed liposomes.
A double-chain glycolipid,dioctadecyl-2-glucopyronosylthio-succinate (1) was synthesized.The glycolipid itself formed stable vesicles.It could also be incorporated into the lipid bilayer membrane to form stable mixed liposomes.
1996, 7(5): 403-406
Abstract:
The title compound was synthesized by condensation of methyl 2-dimethoxyacetyl-4-oxopentanoate and thiourea followed by desulfurization and acid-catalyzed cyclization.
The title compound was synthesized by condensation of methyl 2-dimethoxyacetyl-4-oxopentanoate and thiourea followed by desulfurization and acid-catalyzed cyclization.
1996, 7(5): 407-410
Abstract:
Three new series of triazole compounds were synthesized.The method of synthesis and biological activities of these new compounds were studied.
Three new series of triazole compounds were synthesized.The method of synthesis and biological activities of these new compounds were studied.
1996, 7(5): 411-414
Abstract:
The α,β-unsaturated γ-lactones of neo-clerodane diterpenoids teucvidin,teupernin E and ajugacumbin A were selectively transformed into saturated γ-lactones and unsaturated diol derivatives with NaBH4.These transformations are of interest due to their selective reduction as compared with catalytic hydrogenation and LiAlH4 reduction of these diterpenoid compounds.
The α,β-unsaturated γ-lactones of neo-clerodane diterpenoids teucvidin,teupernin E and ajugacumbin A were selectively transformed into saturated γ-lactones and unsaturated diol derivatives with NaBH4.These transformations are of interest due to their selective reduction as compared with catalytic hydrogenation and LiAlH4 reduction of these diterpenoid compounds.
1996, 7(5): 415-418
Abstract:
(4R,8R,9S)-Camphane[8,9-b]-1,3,2-oxathioborolidine prepared from (1R,2S,3R)-3-mercapto-camphol with borane was used as catalyst in the enantioselective reduction of aromatic ketones:moderate enantioselectivities with e.e.7.44%-51.04% have been obtained for aromatic ketones with 20% mol catalyst,73.78% e.e for ω-bromo acetophenone with 100% mol catalyst.
(4R,8R,9S)-Camphane[8,9-b]-1,3,2-oxathioborolidine prepared from (1R,2S,3R)-3-mercapto-camphol with borane was used as catalyst in the enantioselective reduction of aromatic ketones:moderate enantioselectivities with e.e.7.44%-51.04% have been obtained for aromatic ketones with 20% mol catalyst,73.78% e.e for ω-bromo acetophenone with 100% mol catalyst.
1996, 7(5): 419-422
Abstract:
A direct conversion of 3-acetoxybenzofurans to 3-methoxybenzofurans was realized by refluxing in anhydrous methanolic solution containing hydrogen chloride.
A direct conversion of 3-acetoxybenzofurans to 3-methoxybenzofurans was realized by refluxing in anhydrous methanolic solution containing hydrogen chloride.
1996, 7(5): 423-424
Abstract:
9,10-Dihydroxyphenanthrene was selectively mono-O-glycosylated by a new,one-pot reaction through its activated phospholane intermediate.The reactions were carried out under mild conditions without activation of the anomeric center.
9,10-Dihydroxyphenanthrene was selectively mono-O-glycosylated by a new,one-pot reaction through its activated phospholane intermediate.The reactions were carried out under mild conditions without activation of the anomeric center.
1996, 7(5): 425-426
Abstract:
In the presence of dithionate,excess per (poly) fluoroalkyl iodide reacted with parasubstituted phenolates to provide bis-per (poly) fluoroalkyl substituted phenols in fair to good yields.
In the presence of dithionate,excess per (poly) fluoroalkyl iodide reacted with parasubstituted phenolates to provide bis-per (poly) fluoroalkyl substituted phenols in fair to good yields.
1996, 7(5): 427-430
Abstract:
Salvianolicacid F (la) and przewalskinic acid A (2a) are phenolic acids isolated from the traditional and herbal Chinese medicines Salvia miltiorrhiza (1) and S. przewalskii (2). The chemical structures of these nvo compounds represent the main carbon skeletons of the biologically active depsides salvianolicacid A and B isolated from S.miltiorrhiza (3.4). 丁he present paper reports the synthesis of the methyl ether protected phenolic acids, tetnimetfayl salvianolic acid F (lb) and trimethyl przewaiskinic acid A (2b).
Salvianolicacid F (la) and przewalskinic acid A (2a) are phenolic acids isolated from the traditional and herbal Chinese medicines Salvia miltiorrhiza (1) and S. przewalskii (2). The chemical structures of these nvo compounds represent the main carbon skeletons of the biologically active depsides salvianolicacid A and B isolated from S.miltiorrhiza (3.4). 丁he present paper reports the synthesis of the methyl ether protected phenolic acids, tetnimetfayl salvianolic acid F (lb) and trimethyl przewaiskinic acid A (2b).
1996, 7(5): 431-432
Abstract:
Reaction of C60with excessive potassium in toluene at refluxing temperature results in black precipitate K2C60with high conversion,which can completely be hydrolyzed to prepare the fullerol.Investigations including FT-IR.1H NMR.13C NMR.UV-Vis and FABMS of the product were reponed.
Reaction of C60with excessive potassium in toluene at refluxing temperature results in black precipitate K2C60with high conversion,which can completely be hydrolyzed to prepare the fullerol.Investigations including FT-IR.1H NMR.13C NMR.UV-Vis and FABMS of the product were reponed.
1996, 7(5): 433-436
Abstract:
A new method for the preparation of polyalkyl and polyarenefullerene derivatives C60(RH)n (R=Bu,n=1-3;R=Ph,n=1-10) by the reaction of C60 with organotin hydride in toluene is described.Another series of products of stannanes RaSnbHc (R=Bu,a=3-8,b=1-4,c=0-3;R=Ph,a=3-11,b=1-5,c=0-4) were also obtained,which shows that C60 can catalyze polymerization of organic-tin.These products were determined by mass and infrared spectrometry.And the possible reaction mechanisms are discussed.
A new method for the preparation of polyalkyl and polyarenefullerene derivatives C60(RH)n (R=Bu,n=1-3;R=Ph,n=1-10) by the reaction of C60 with organotin hydride in toluene is described.Another series of products of stannanes RaSnbHc (R=Bu,a=3-8,b=1-4,c=0-3;R=Ph,a=3-11,b=1-5,c=0-4) were also obtained,which shows that C60 can catalyze polymerization of organic-tin.These products were determined by mass and infrared spectrometry.And the possible reaction mechanisms are discussed.
1996, 7(5): 437-438
Abstract:
In this work,the effects of chemical modification on the activity and enantioselectivity of Candida lypolytica lipase in resolution of Ibuprofen were reported.
In this work,the effects of chemical modification on the activity and enantioselectivity of Candida lypolytica lipase in resolution of Ibuprofen were reported.
1996, 7(5): 439-440
Abstract:
A new monoester of the tetracyclic diterpene ingenol was isolated from Euphorbia petiolata and its structure was elucidated by spectroscopic methods and chemical transformation as ingenol-3-O-(2'E,4'Z)-tetradecadienoate.
A new monoester of the tetracyclic diterpene ingenol was isolated from Euphorbia petiolata and its structure was elucidated by spectroscopic methods and chemical transformation as ingenol-3-O-(2'E,4'Z)-tetradecadienoate.
1996, 7(5): 441-442
Abstract:
From the herbs of Coleus scutellarioides,a new diterpenoid was isolated and identified as 2-(2'ξ-methoxypropyl)-3-hydroxy-5,7,8-trimethylphenanthrene-1,4-dione,named as scutequinone (1).
From the herbs of Coleus scutellarioides,a new diterpenoid was isolated and identified as 2-(2'ξ-methoxypropyl)-3-hydroxy-5,7,8-trimethylphenanthrene-1,4-dione,named as scutequinone (1).
1996, 7(5): 443-444
Abstract:
A new norditerpenoid alkaloid,6-epichasmanine,was isolated from the roots of Aconitum kusnezoffii.Its structure was determind on the basis of spectrscopic analysis.
A new norditerpenoid alkaloid,6-epichasmanine,was isolated from the roots of Aconitum kusnezoffii.Its structure was determind on the basis of spectrscopic analysis.
1996, 7(5): 445-448
Abstract:
Two new phenylpropanoid glycosides,incanoside A and B were isolated from the whole plant of Caryopteris incana (Thunb) Miq.On the basis of chemical and spectral evidence,incanosides A and B were determined as 3-hydroxy-4-methoxy-β-phenylethyl α-L-rhamnopyranosyl (1→3)-β-D-glucopyranosyl (1→2)-6-O-reruloyl-β-D-glucopyranoside and 3-hydroxy-4-methoxy-β-phenylethyl α-L-rhamnopyranosyl (1→3)-β-D-glucopyranosyl (1→2)-β-D-glucopyranoside,respectively.
Two new phenylpropanoid glycosides,incanoside A and B were isolated from the whole plant of Caryopteris incana (Thunb) Miq.On the basis of chemical and spectral evidence,incanosides A and B were determined as 3-hydroxy-4-methoxy-β-phenylethyl α-L-rhamnopyranosyl (1→3)-β-D-glucopyranosyl (1→2)-6-O-reruloyl-β-D-glucopyranoside and 3-hydroxy-4-methoxy-β-phenylethyl α-L-rhamnopyranosyl (1→3)-β-D-glucopyranosyl (1→2)-β-D-glucopyranoside,respectively.
1996, 7(5): 449-452
Abstract:
Two new depsidic glycosides salviaflaside and its methyl ester were isolated from the aqueous extract of Salvia flava.Their structures were elucidated by spectral analysis,especially by 2D NMR analysis.
Two new depsidic glycosides salviaflaside and its methyl ester were isolated from the aqueous extract of Salvia flava.Their structures were elucidated by spectral analysis,especially by 2D NMR analysis.
1996, 7(5): 453-456
Abstract:
Terbium can form a stable binary chelate with terephthalic acid (benzene-1.4-dicarboxylic acid(TPA)) having a ratio of 1:2 in aqueous solution in the pH range of 5~6.The maximum excitation and emission wavelengths are 260 nm and 545 nm for terbium chelate,respectively.The fluorescence intensity of terbium chelate remains stable in 8 h with a relative standard deviation in the range of =4%.The rest or the lanthanide ions and the common foreign ions hardly interfere the determination.
Terbium can form a stable binary chelate with terephthalic acid (benzene-1.4-dicarboxylic acid(TPA)) having a ratio of 1:2 in aqueous solution in the pH range of 5~6.The maximum excitation and emission wavelengths are 260 nm and 545 nm for terbium chelate,respectively.The fluorescence intensity of terbium chelate remains stable in 8 h with a relative standard deviation in the range of =4%.The rest or the lanthanide ions and the common foreign ions hardly interfere the determination.
1996, 7(5): 457-458
Abstract:
Ac impedance responses of electrolytic manganese dioxide (EMD) electrode are measured with EIS.It was found that the impedance responses are consistent with the constant phase element (CPE) form and calculated the fractal dimension of MnO2.
Ac impedance responses of electrolytic manganese dioxide (EMD) electrode are measured with EIS.It was found that the impedance responses are consistent with the constant phase element (CPE) form and calculated the fractal dimension of MnO2.
1996, 7(5): 459-462
Abstract:
A selective new reagent Wazo-1 was prepared.This paper studied the properties of its fluorescence and UV-Spectrum.A new fluorescence method for the determination of calcium is developed.Wazo-1 reac■s with calcium.forms calcium complex (Ex=297nm;Em=370nm).The interference of Mg(Ⅱ) has been studied.The reagent has better selectivity to Ca(Ⅱ) in the presence of large amount of Mg(Ⅱ).Flucrescence method has-been used for the determination of microamounts of calcium in serum with new reagent Wazo-1.The results obtained are favourable.
A selective new reagent Wazo-1 was prepared.This paper studied the properties of its fluorescence and UV-Spectrum.A new fluorescence method for the determination of calcium is developed.Wazo-1 reac■s with calcium.forms calcium complex (Ex=297nm;Em=370nm).The interference of Mg(Ⅱ) has been studied.The reagent has better selectivity to Ca(Ⅱ) in the presence of large amount of Mg(Ⅱ).Flucrescence method has-been used for the determination of microamounts of calcium in serum with new reagent Wazo-1.The results obtained are favourable.
1996, 7(5): 463-466
Abstract:
A new initiator,potassium diperiodatoargentate (Ⅲ),was used to initiate graft copolymerization of butyl acrylate(BuA) onto casein which showed a very high grafting efficiency.Grafting efficiency and percent conversion of monomer were evaluated in all cases.Infrared spectra and thermal analysis for casein and the grafting copolymer were taken to establish evidence for grafting.A possible initiation mechanism was proposed.
A new initiator,potassium diperiodatoargentate (Ⅲ),was used to initiate graft copolymerization of butyl acrylate(BuA) onto casein which showed a very high grafting efficiency.Grafting efficiency and percent conversion of monomer were evaluated in all cases.Infrared spectra and thermal analysis for casein and the grafting copolymer were taken to establish evidence for grafting.A possible initiation mechanism was proposed.
1996, 7(5): 467-470
Abstract:
In the purpose of study on the electronic structure feature for the activation center of the FeMo-cofactor of the nitrogenase as well as activation process of a dinitrogen molecule.the black Roussinate with an Fe4S3 cluster core is regarded as the first modeling complex.In this paper,natural bond orbitals for the cluster anions of the black Roussinate and the related red Roussinate are calculated on the basis of the first-order density matrixes obtained by the use of DV-Xα SCC method,leading to reasonable bonding patterns.
In the purpose of study on the electronic structure feature for the activation center of the FeMo-cofactor of the nitrogenase as well as activation process of a dinitrogen molecule.the black Roussinate with an Fe4S3 cluster core is regarded as the first modeling complex.In this paper,natural bond orbitals for the cluster anions of the black Roussinate and the related red Roussinate are calculated on the basis of the first-order density matrixes obtained by the use of DV-Xα SCC method,leading to reasonable bonding patterns.
1996, 7(5): 471-474
Abstract:
The reaction path of the reaction CH(2π)-H2→CH3 is traced with IRC theory and MCSCF,6-31G method.On this basis,the dynamical properties and VTST rate constants are investigated.The results show that the curvature of the reaction path is considerable and its effects to rate constants are sensitive.
The reaction path of the reaction CH(2π)-H2→CH3 is traced with IRC theory and MCSCF,6-31G method.On this basis,the dynamical properties and VTST rate constants are investigated.The results show that the curvature of the reaction path is considerable and its effects to rate constants are sensitive.
1996, 7(5): 475-478
Abstract:
For investigating the 4Σ-→ 4Σ- transition in the FO radical to which an observed 268 nm ASE line has been attributed,the potential energy curves of the four lowest-lying 4A2 states of FO have been calculated using the MRSDCI method.The results indicate that the first 4Σ- (l4A2) and the upper 4Σ-(44A2) states are weakly bound and bound states respectively,and the 24A2 and 34A2 states are both repulsive states which are not relevant to the emission.The predicted Te value for the 4Σ-→ 4Σ- transition is 4.62 eV,which is in excellent agreement with the photon energy value (4.63 eV) of the ASE line.The procedure of our MRSDCI calculations for excited states is described in detail,and the previous calculation results for these states are discussed.
For investigating the 4Σ-→ 4Σ- transition in the FO radical to which an observed 268 nm ASE line has been attributed,the potential energy curves of the four lowest-lying 4A2 states of FO have been calculated using the MRSDCI method.The results indicate that the first 4Σ- (l4A2) and the upper 4Σ-(44A2) states are weakly bound and bound states respectively,and the 24A2 and 34A2 states are both repulsive states which are not relevant to the emission.The predicted Te value for the 4Σ-→ 4Σ- transition is 4.62 eV,which is in excellent agreement with the photon energy value (4.63 eV) of the ASE line.The procedure of our MRSDCI calculations for excited states is described in detail,and the previous calculation results for these states are discussed.
1996, 7(5): 479-482
Abstract:
On the basis of the capture potential of force field and the adiabatic invariance proposed by Bates,the quadratic force constants between divalent metal ions in ⅡB group and ligands were calculated.Compared with the experimental results,the calculated contants are satisfactory and the reasons for the difference are given.
On the basis of the capture potential of force field and the adiabatic invariance proposed by Bates,the quadratic force constants between divalent metal ions in ⅡB group and ligands were calculated.Compared with the experimental results,the calculated contants are satisfactory and the reasons for the difference are given.
1996, 7(5): 483-486
Abstract:
The phase diagram of ternary system LaCl3-SrCl2-LiCl has been investigated by means of DTA.It was found that there were three fields corresponding to primary crystallization of LaCl3,SrCl2 and LiCl respectively,three univeriant curves related to the secondary crystallization,a ternary eutectic E(46.8% LaCl3,25.4% SrCl2,30.0%LiCl;469℃) in the system.A ternary reaction occurred in the system:L=LaCl3+SrCl2+LiCl
The phase diagram of ternary system LaCl3-SrCl2-LiCl has been investigated by means of DTA.It was found that there were three fields corresponding to primary crystallization of LaCl3,SrCl2 and LiCl respectively,three univeriant curves related to the secondary crystallization,a ternary eutectic E(46.8% LaCl3,25.4% SrCl2,30.0%LiCl;469℃) in the system.A ternary reaction occurred in the system:L=LaCl3+SrCl2+LiCl
1996, 7(5): 487-490
Abstract:
A MgO sample treated with shock wave was studied by using electron spin resonance(ESR) spectroscopy.An isotropic ESR singal at g=2.002 could be designated to F centers.O2superoxide ions penetrated into the surface layer of MgO powder after shocking were identified at gxx=2.006,gyy=2.009,and gzz=2.023,2.025.The change of surface adsorption ability for O2 of shocked MgO was discussed.
A MgO sample treated with shock wave was studied by using electron spin resonance(ESR) spectroscopy.An isotropic ESR singal at g=2.002 could be designated to F centers.O2superoxide ions penetrated into the surface layer of MgO powder after shocking were identified at gxx=2.006,gyy=2.009,and gzz=2.023,2.025.The change of surface adsorption ability for O2 of shocked MgO was discussed.
1996, 7(5): 491-492
Abstract:
Zeolite HZSM-5 calcined at different temperatures were studied by29Si MAS NMR and EPR methods.It was concluded that in certain temperature range,dealumination did not necessarily occur simultaneously with framework dehydroxylation and thus framework Lewis acidic sites emerged.Two processes may be operative with one of them being predominant at different temperatures.
Zeolite HZSM-5 calcined at different temperatures were studied by29Si MAS NMR and EPR methods.It was concluded that in certain temperature range,dealumination did not necessarily occur simultaneously with framework dehydroxylation and thus framework Lewis acidic sites emerged.Two processes may be operative with one of them being predominant at different temperatures.
1996, 7(5): 493-494
Abstract:
Ultrafine SnOx thin films were prepared from tetrabutyltin by RF glow dis charge polymerization. Annealing behaviour of films under air and gas-sensitive property were investigated.The ultrafine SnOx thin film with average particle size of 6nm exhibited a high sensitivity of 30 to 500ppm EtOH at 200℃.
Ultrafine SnOx thin films were prepared from tetrabutyltin by RF glow dis charge polymerization. Annealing behaviour of films under air and gas-sensitive property were investigated.The ultrafine SnOx thin film with average particle size of 6nm exhibited a high sensitivity of 30 to 500ppm EtOH at 200℃.
1996, 7(5): 495-496
Abstract:
Nanocrystalline TiO2 thin films have been prepared on a conducting glass surface by coating quantized TiO2 colloids.The photoelectrochemical properties of TiO2 thin films and their dependence on various factors have been studied.To obtain maximum photocurrent optimization of film thickness,sintering temperature and the pH of the electrolyte are very important.
Nanocrystalline TiO2 thin films have been prepared on a conducting glass surface by coating quantized TiO2 colloids.The photoelectrochemical properties of TiO2 thin films and their dependence on various factors have been studied.To obtain maximum photocurrent optimization of film thickness,sintering temperature and the pH of the electrolyte are very important.
1996, 7(5): 497-498
Abstract:
The surface compositional changes of Ni3Ti(0001) induced by oxygen exposure have been examined at different dosing temperatures.Oxygen induced segregation of titanium occurs rapidly above 500℃,but only rearrangement betweeen nickel and titanium in the outer two or more layers occurs upon oxygen exposure at room temperature.Oxygen atoms penetrate into the sublayers of Ni3Ti(0001) at 500℃ and reside mainly on the surface at room temperature.
The surface compositional changes of Ni3Ti(0001) induced by oxygen exposure have been examined at different dosing temperatures.Oxygen induced segregation of titanium occurs rapidly above 500℃,but only rearrangement betweeen nickel and titanium in the outer two or more layers occurs upon oxygen exposure at room temperature.Oxygen atoms penetrate into the sublayers of Ni3Ti(0001) at 500℃ and reside mainly on the surface at room temperature.
1996, 7(5): 499-502
Abstract:
Through the application of the method of double substitute calibration using the true isotopic ratios of cerium and europium of our laboratory standards,the atomic weight of ytterbium has been determined as A■(Yb)=173. 0428(15) on 2σ basis.
Through the application of the method of double substitute calibration using the true isotopic ratios of cerium and europium of our laboratory standards,the atomic weight of ytterbium has been determined as A■(Yb)=173. 0428(15) on 2σ basis.
