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1991 Volume 2 Issue 4
1991, 2(4): 267-268
Abstract:
Mono-substituted heterocyclic ketene aminals are formed by the reaction of 1-methyl-2-methylthio-imidazoline with active methylene compounds containinq an acetyl or benzoyl group by the elimination of both a methylthio and an acyl group.This is resulted by the secondary reactio of the produced methanethiol to attack the more active carbonyl group.
Mono-substituted heterocyclic ketene aminals are formed by the reaction of 1-methyl-2-methylthio-imidazoline with active methylene compounds containinq an acetyl or benzoyl group by the elimination of both a methylthio and an acyl group.This is resulted by the secondary reactio of the produced methanethiol to attack the more active carbonyl group.
1991, 2(4): 269-272
Abstract:
In the synthesis of l-phenyl-5-substituted amino-4-pyrazole N-alkyl amide,it was found for the first time that one of the two aromatic amido groups in the molecule of 1-phenyl-5-benzoyl amino-4-pyrazole N-alkyl amide was reduced selectively by LiAlH4.A new conclusion was drawn after several experiments have been done that ortho-amino(or substituted amino)aryl amide or the aryl amide with its ortho substituent which can be reduced into an amino group(or substituted amino group)can not be reduced by LiAlH4.It was further rationalized by quantum chemical calculation.
In the synthesis of l-phenyl-5-substituted amino-4-pyrazole N-alkyl amide,it was found for the first time that one of the two aromatic amido groups in the molecule of 1-phenyl-5-benzoyl amino-4-pyrazole N-alkyl amide was reduced selectively by LiAlH4.A new conclusion was drawn after several experiments have been done that ortho-amino(or substituted amino)aryl amide or the aryl amide with its ortho substituent which can be reduced into an amino group(or substituted amino group)can not be reduced by LiAlH4.It was further rationalized by quantum chemical calculation.
1991, 2(4): 273-274
Abstract:
A new approach to the synthesis of 2,2″-biflavanones by the reductive dimerization of flavones is reported.The racemate and meso compounds of each bitlavanone have been separated and their structures have been determined on the basis of their spectral data.
A new approach to the synthesis of 2,2″-biflavanones by the reductive dimerization of flavones is reported.The racemate and meso compounds of each bitlavanone have been separated and their structures have been determined on the basis of their spectral data.
1991, 2(4): 275-276
Abstract:
Under the condition of solid-liquid phase transfer catalysis,olefins were obtained by the reaction of p-nitrobenzyldibutyltelluronium bromide with aromatic aldehyde.Under the condition of liquid-liquid phase transfer catalysis,however,different products were obtained due to the reactivity of different bases or aldehydes.
Under the condition of solid-liquid phase transfer catalysis,olefins were obtained by the reaction of p-nitrobenzyldibutyltelluronium bromide with aromatic aldehyde.Under the condition of liquid-liquid phase transfer catalysis,however,different products were obtained due to the reactivity of different bases or aldehydes.
1991, 2(4): 277-278
Abstract:
A series of 3,6-disubstituted s-triazolo[3,4-b]-1,3,4-thiadiazoles have been synthesized,whose structures were determined by elemental and spectral analyses;all the new compounds showed significant antibacterial activity.
A series of 3,6-disubstituted s-triazolo[3,4-b]-1,3,4-thiadiazoles have been synthesized,whose structures were determined by elemental and spectral analyses;all the new compounds showed significant antibacterial activity.
1991, 2(4): 279-280
Abstract:
A new rhodium(Ⅱ) porphyrin complex was isolated by chromatography from the photochemical reaction of(μ—tetraphenylporphyrinato)bis[dicarbonylrhodium(Ⅰ)]with pyridine in benzene and has been characterized.From the results,the reaction mechanism is proposed.
A new rhodium(Ⅱ) porphyrin complex was isolated by chromatography from the photochemical reaction of(μ—tetraphenylporphyrinato)bis[dicarbonylrhodium(Ⅰ)]with pyridine in benzene and has been characterized.From the results,the reaction mechanism is proposed.
1991, 2(4): 281-284
Abstract:
A new triad model compound porphyrin-viologen-carbazole was synthesized to mimic photosynthesis.A mechanism including photoinduced electron transfer and two-step charge separation was suggested.This triad compound was easy to form LB film and rather high photodriven voltage and current were obtained with only one layer of LB film on the surface of SnO2 conductive glass.
A new triad model compound porphyrin-viologen-carbazole was synthesized to mimic photosynthesis.A mechanism including photoinduced electron transfer and two-step charge separation was suggested.This triad compound was easy to form LB film and rather high photodriven voltage and current were obtained with only one layer of LB film on the surface of SnO2 conductive glass.
1991, 2(4): 285-288
Abstract:
α,ε-N,N'-bis(L-cysteinyl)-L-lysine was synthesized and characterized for the first time.It was then employed as a bifunctional chelating agent to chelate technetium-99m and subsequently conjugated to fragment F(ab')2 of anti-gastric tumor monoclonal antibody 3G9.The radiolabelled antibody was satisfactorily stable and immunoreactive.
α,ε-N,N'-bis(L-cysteinyl)-L-lysine was synthesized and characterized for the first time.It was then employed as a bifunctional chelating agent to chelate technetium-99m and subsequently conjugated to fragment F(ab')2 of anti-gastric tumor monoclonal antibody 3G9.The radiolabelled antibody was satisfactorily stable and immunoreactive.
1991, 2(4): 289-290
Abstract:
The obstinated amino acid,Boc-Asn(or Boc-Gln),was directly anchored onto the Merrifield's resin using DCHA as the base in present reaction.The yield(71.88%)of Boc-Asn-OCH2-resin was much better than those(0-33.5%)using Cs2CO3,KOH,KF.DEA and TEA as the base.which are efficient reagents for other amino acids in the same reaction.
The obstinated amino acid,Boc-Asn(or Boc-Gln),was directly anchored onto the Merrifield's resin using DCHA as the base in present reaction.The yield(71.88%)of Boc-Asn-OCH2-resin was much better than those(0-33.5%)using Cs2CO3,KOH,KF.DEA and TEA as the base.which are efficient reagents for other amino acids in the same reaction.
1991, 2(4): 291-292
Abstract:
The structures of two novel lactams isolated from Clausena lansium were elucidated mainly on the bases of their spectral data.They are homoclausenamide(1),a δ-lactam,and zetaclausenamide(4),an eight-membered ring lactam.
The structures of two novel lactams isolated from Clausena lansium were elucidated mainly on the bases of their spectral data.They are homoclausenamide(1),a δ-lactam,and zetaclausenamide(4),an eight-membered ring lactam.
1991, 2(4): 293-296
Abstract:
Five ent-6,7-seco-karuene diterpenoids-enmein,epinodosin,sculponeatin A,C,D,were isolated from the dried leaves of Rabdosia sculponeata. One of the compounds,named sculponeatin D,was previously unreported.Its structre was elucidated by the spectral data including 2D COSY,1H-13C correlation,2D NOESY spectroscopy.
Five ent-6,7-seco-karuene diterpenoids-enmein,epinodosin,sculponeatin A,C,D,were isolated from the dried leaves of Rabdosia sculponeata. One of the compounds,named sculponeatin D,was previously unreported.Its structre was elucidated by the spectral data including 2D COSY,1H-13C correlation,2D NOESY spectroscopy.
1991, 2(4): 297-298
Abstract:
Amsosinine,a new indole alkaloid was isolated from Amsonia sinensis.Its structure and relative configuration have been determined by detailed spectral studies.The X-ray crystal structure analysis further confirms our assignments.
Amsosinine,a new indole alkaloid was isolated from Amsonia sinensis.Its structure and relative configuration have been determined by detailed spectral studies.The X-ray crystal structure analysis further confirms our assignments.
1991, 2(4): 299-300
Abstract:
The structure of a new saponin mussaendoside M obtained from Mussaenda pubesecus was identified by FAB-MS and 2D-NMR spectroscopy
The structure of a new saponin mussaendoside M obtained from Mussaenda pubesecus was identified by FAB-MS and 2D-NMR spectroscopy
1991, 2(4): 301-302
Abstract:
From the root of Salvia przewalskii Maxim.a new phenolic acid,przewalskinic acid A was isolated and the structure was established by the analysis of 13C-NMR,1H-NMR and two-dimensional COSY experiments.
From the root of Salvia przewalskii Maxim.a new phenolic acid,przewalskinic acid A was isolated and the structure was established by the analysis of 13C-NMR,1H-NMR and two-dimensional COSY experiments.
1991, 2(4): 303-306
Abstract:
Present paper deals with propylene oxide production from propylene utilizing Methylomonas sp.GYJ3 immobilized by adsorption or gel entrapment in a continuous gas flow packed bed bioreactor.The regeneration of biocatalyst in situ is also discussed.
Present paper deals with propylene oxide production from propylene utilizing Methylomonas sp.GYJ3 immobilized by adsorption or gel entrapment in a continuous gas flow packed bed bioreactor.The regeneration of biocatalyst in situ is also discussed.
1991, 2(4): 307-308
Abstract:
Three new metabolites(N-acetyl-pseudoephedrine,N-acetyl-norpseudoephedrine and N,O-diacetylnorpseudoephedrine)of ephedrines were diected and confirmed by GC/MS method and chemical derivatization.The metabolic pathway of acetylation of hydroxyl group is reported for the first time.
Three new metabolites(N-acetyl-pseudoephedrine,N-acetyl-norpseudoephedrine and N,O-diacetylnorpseudoephedrine)of ephedrines were diected and confirmed by GC/MS method and chemical derivatization.The metabolic pathway of acetylation of hydroxyl group is reported for the first time.
1991, 2(4): 309-312
Abstract:
A microcomputer-based UV/V in situ spectroelectrochemical measurement system has been developed.This paper presents a description of the experimental details regarding the methods and equipment.
A microcomputer-based UV/V in situ spectroelectrochemical measurement system has been developed.This paper presents a description of the experimental details regarding the methods and equipment.
1991, 2(4): 313-314
Abstract:
Sulfur dioxide has been found to decrease the chemiluminescence of luminol-iodine system.A new determination method for sulfur dioxide in atmosphere is developed by applying this reaction to a flow injection gas diffusion separation system.This permits the determination of sulfur dioxide selectively and rapidly.
Sulfur dioxide has been found to decrease the chemiluminescence of luminol-iodine system.A new determination method for sulfur dioxide in atmosphere is developed by applying this reaction to a flow injection gas diffusion separation system.This permits the determination of sulfur dioxide selectively and rapidly.
1991, 2(4): 315-316
Abstract:
Reaction of(n-Bu4N)xNa4-x[a-Mo8O26](x=1-4)and mpH2(mpH2=o-mercaptophenol) leads to the formation of compound(n-Bu4N)[Mo2O3(mp)3Na(EtOH)2(MeOH)],It crystallizes in the space group P21/n with four molecules per unit cell.The cell dimension is a=12.776(3),b=14.154(5),c=26.281(7) Å,β=95.50(2)°,V=4730.5Å3,dc=1.407g/cm3.Full-matrix refinement of 496 parameters on 3348 reflection data gave final R(Rw)value of 0.072(0.072).The two oxomolybdenum-mercaptophenolate,units are triply bridged by an inorganic oxygen atom and a doubly bridging mp2-ligand.
Reaction of(n-Bu4N)xNa4-x[a-Mo8O26](x=1-4)and mpH2(mpH2=o-mercaptophenol) leads to the formation of compound(n-Bu4N)[Mo2O3(mp)3Na(EtOH)2(MeOH)],It crystallizes in the space group P21/n with four molecules per unit cell.The cell dimension is a=12.776(3),b=14.154(5),c=26.281(7) Å,β=95.50(2)°,V=4730.5Å3,dc=1.407g/cm3.Full-matrix refinement of 496 parameters on 3348 reflection data gave final R(Rw)value of 0.072(0.072).The two oxomolybdenum-mercaptophenolate,units are triply bridged by an inorganic oxygen atom and a doubly bridging mp2-ligand.
1991, 2(4): 317-320
Abstract:
The coordination compounds,{Cu[CH3C6H4N(CH2COO)2]}·2H2O and {Cu[CH3OC6H4N(CH2COO)2]}·2H2O,have been prepared and its crystal structures determined.The final discrepancy factors are R=0.052,Rw=0.061 for(I)and R=0.052,Rw=0.039 for(Ⅱ).The geometry of the coordination polyhedron with Cu(Ⅱ)is a distorted tetragonal pyramid for(Ⅰ)and an unsymmetrical and extended tetragonal bipyramid for(Ⅱ),respectively.The results of EHMO calculations indicate that the ligand mainly provided the field with very few of its electrons being coordinated to the central atom.
The coordination compounds,{Cu[CH3C6H4N(CH2COO)2]}·2H2O and {Cu[CH3OC6H4N(CH2COO)2]}·2H2O,have been prepared and its crystal structures determined.The final discrepancy factors are R=0.052,Rw=0.061 for(I)and R=0.052,Rw=0.039 for(Ⅱ).The geometry of the coordination polyhedron with Cu(Ⅱ)is a distorted tetragonal pyramid for(Ⅰ)and an unsymmetrical and extended tetragonal bipyramid for(Ⅱ),respectively.The results of EHMO calculations indicate that the ligand mainly provided the field with very few of its electrons being coordinated to the central atom.
1991, 2(4): 321-322
Abstract:
X-ray diffraction line profiles of low density polyethylene(LDPE)/(ethylene-propylene-octene-1)copolymer(EPO) blends have been analyzed with variance range function method.Theories for determining the microparacrystallite size and the distortion parameter from single reflection have been described,and the value of these two parameters at(110)and(200)directions have been determined.
X-ray diffraction line profiles of low density polyethylene(LDPE)/(ethylene-propylene-octene-1)copolymer(EPO) blends have been analyzed with variance range function method.Theories for determining the microparacrystallite size and the distortion parameter from single reflection have been described,and the value of these two parameters at(110)and(200)directions have been determined.
1991, 2(4): 323-324
Abstract:
Based on the X-ray scattering intensity theory,the correction factors of the degree of crystallinity formulae of the multicomponent polymers have been clearly defined.The formula of degree of erystallinity of the multicomponent polymers was derived in terms of the WAXD theory ahd improved graphic multipeak resolution methods.The results calculated are compatible with the density measurement.
Based on the X-ray scattering intensity theory,the correction factors of the degree of crystallinity formulae of the multicomponent polymers have been clearly defined.The formula of degree of erystallinity of the multicomponent polymers was derived in terms of the WAXD theory ahd improved graphic multipeak resolution methods.The results calculated are compatible with the density measurement.
1991, 2(4): 325-328
Abstract:
This paper presents a character table of S4 wr S2 wreath product group.Using this character table,1H or 13C NMR spectra analysis of molecula with S4[S2]symmetry,especially simplification of the secular determinant equation will be easy to carry out.Molecules with S4[S2]symmetry,are exemplified by octaphenylcyclotetrasiloxane and 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine chromium(Ⅲ)chloride.
This paper presents a character table of S4 wr S2 wreath product group.Using this character table,1H or 13C NMR spectra analysis of molecula with S4[S2]symmetry,especially simplification of the secular determinant equation will be easy to carry out.Molecules with S4[S2]symmetry,are exemplified by octaphenylcyclotetrasiloxane and 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine chromium(Ⅲ)chloride.
1991, 2(4): 329-330
Abstract:
A novel design of IR OTTLE is shown to have sufficient sensitivity and experimental simplicity for obtaining IR spectra of the species generated during electrochemical oxidation-reduction.
A novel design of IR OTTLE is shown to have sufficient sensitivity and experimental simplicity for obtaining IR spectra of the species generated during electrochemical oxidation-reduction.
1991, 2(4): 331-334
Abstract:
A series of nine Pd(0)complexes(L)Pd(L')[L=bis(diphenylphosphino)methane(dppm),1,2-bis(diphenylphosphino)ethane(dppe),and 1,1'-bis(diphenylphosphino)ferrocene(dppf),respectively;L=dibenzylideneacetone(dba),2,3,5,6-tetrachloro-1.4-benzoquinone(q)and 2,3-dichloro-1,4-naphthoquinone(nq)]were synthesized and characterized by means of elemental analyses,IR,UV,1H-NMR and 31P-NMR spectra.The redox wave peak potentials of the ferrocenyl group of complexes with dppf were measured by using CV method.Results showed that all the diphosphorus ligands behaved as chelating bidentate ligand and dba,q,nq were coordinated to the Pd(0)atom through their C=C moieties,not their carbonyl ones.Analytical data also showed that there were interactions between the two different ligands in each complex.
A series of nine Pd(0)complexes(L)Pd(L')[L=bis(diphenylphosphino)methane(dppm),1,2-bis(diphenylphosphino)ethane(dppe),and 1,1'-bis(diphenylphosphino)ferrocene(dppf),respectively;L=dibenzylideneacetone(dba),2,3,5,6-tetrachloro-1.4-benzoquinone(q)and 2,3-dichloro-1,4-naphthoquinone(nq)]were synthesized and characterized by means of elemental analyses,IR,UV,1H-NMR and 31P-NMR spectra.The redox wave peak potentials of the ferrocenyl group of complexes with dppf were measured by using CV method.Results showed that all the diphosphorus ligands behaved as chelating bidentate ligand and dba,q,nq were coordinated to the Pd(0)atom through their C=C moieties,not their carbonyl ones.Analytical data also showed that there were interactions between the two different ligands in each complex.
1991, 2(4): 335-338
Abstract:
The reaction of Co2(CO)8 with EtSPCl2 gives a new crystal like compound Co7(μ7-S)(μ4-PSEt)(μ-SEt)2(μ-CO)2(CO)12,whose structure has been determined by single crystal x-ray diffraction.This special compound reveals some new features in cluster chemistry1:The fragmentation of a ligand precursor EtSPCl2 yieldsthree kinds of fragments,μ7-S,μ4-PSEt and μ-SEt,which are ligands in the same cluster molecule.There is a new type of bridging S presented——A μ7-S atom is interspaced into seven Co core.
The reaction of Co2(CO)8 with EtSPCl2 gives a new crystal like compound Co7(μ7-S)(μ4-PSEt)(μ-SEt)2(μ-CO)2(CO)12,whose structure has been determined by single crystal x-ray diffraction.This special compound reveals some new features in cluster chemistry1:The fragmentation of a ligand precursor EtSPCl2 yieldsthree kinds of fragments,μ7-S,μ4-PSEt and μ-SEt,which are ligands in the same cluster molecule.There is a new type of bridging S presented——A μ7-S atom is interspaced into seven Co core.
1991, 2(4): 339-342
Abstract:
Acyl chloride can efficiently be converted into anhydride under solid liquid phase transfer catalysis by using bis(triphenylphosphine) cobalt dichloride or bis(triphenylphospine)palladium dichloride as the catalyst.
Acyl chloride can efficiently be converted into anhydride under solid liquid phase transfer catalysis by using bis(triphenylphosphine) cobalt dichloride or bis(triphenylphospine)palladium dichloride as the catalyst.
1991, 2(4): 343-344
Abstract:
A thorough investigation have been first carried out on the electron transferring between molecules by using the ab initio electrostatic potential method.By this method,we made a theoretical estimation of the energy barrier that electrons tunnel when they move from one molecule to another.The results show that for two molecules very close to each other the height of the barrier goes down exponentially with a decreasing intermolecular distance.Substituting groups have effect on the height of the barrier.The photoelectric current produced in a simulative system has also been theoretically predicted.
A thorough investigation have been first carried out on the electron transferring between molecules by using the ab initio electrostatic potential method.By this method,we made a theoretical estimation of the energy barrier that electrons tunnel when they move from one molecule to another.The results show that for two molecules very close to each other the height of the barrier goes down exponentially with a decreasing intermolecular distance.Substituting groups have effect on the height of the barrier.The photoelectric current produced in a simulative system has also been theoretically predicted.
