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1993 Volume 4 Issue 5
1993, 4(5): 377-378
Abstract:
The facile and regioselective synthesis of some novel phenylsulfones bearing isoprene units were accomplished by using the corresponding terpenoid compounds as the starting material through ene-chlorination and phenylsulfonyl group substritution steps. The yields are excellent and the experimental conditions are very mild.
The facile and regioselective synthesis of some novel phenylsulfones bearing isoprene units were accomplished by using the corresponding terpenoid compounds as the starting material through ene-chlorination and phenylsulfonyl group substritution steps. The yields are excellent and the experimental conditions are very mild.
1993, 4(5): 379-380
Abstract:
In this paper, six N,N'-disubstituted aonothioxamides were synthesized and the reactions between these monothioxamines and diamines (1,2-diamino ethane and 1,3-diamino propane) were studied. Some new compounds were synthesized by using these reactions.
In this paper, six N,N'-disubstituted aonothioxamides were synthesized and the reactions between these monothioxamines and diamines (1,2-diamino ethane and 1,3-diamino propane) were studied. Some new compounds were synthesized by using these reactions.
1993, 4(5): 381-384
Abstract:
The rapid alkylation of methyl N-benzylidene glycinate with halides under microwave irradiation using solid-liquid phase transfer condition without solvent has been achieved wilhin only one minute. After hydrolysis of alkylated products the corresponding α-amino acids were obtained in overall yield 43.6~62.5%.
The rapid alkylation of methyl N-benzylidene glycinate with halides under microwave irradiation using solid-liquid phase transfer condition without solvent has been achieved wilhin only one minute. After hydrolysis of alkylated products the corresponding α-amino acids were obtained in overall yield 43.6~62.5%.
1993, 4(5): 385-386
Abstract:
The reactions of tri-2-benzofuranylborane or aminoethyl di-2-thienylborinate and 2-thienylphenylborinate with dichlorocarbene generated in situ from chloroform under phase transfer conditions were explored as a new route for the preparation of heteroaromatic ketones. It was found that a good yield of the ketones can be obtained by solid-liquid system.
The reactions of tri-2-benzofuranylborane or aminoethyl di-2-thienylborinate and 2-thienylphenylborinate with dichlorocarbene generated in situ from chloroform under phase transfer conditions were explored as a new route for the preparation of heteroaromatic ketones. It was found that a good yield of the ketones can be obtained by solid-liquid system.
1993, 4(5): 387-390
Abstract:
β-(2-imidazolinyl)-ethyl methyl diethoxy silane quarternary halides and its condensed polymers with bisphenol A were synthesized and characterized. The polycationpolyanion complexes were prepared by the condensed polymers and poly (styrene sulfonate). The solubility and thermal stability of interpolymeric complexes were investigated.
β-(2-imidazolinyl)-ethyl methyl diethoxy silane quarternary halides and its condensed polymers with bisphenol A were synthesized and characterized. The polycationpolyanion complexes were prepared by the condensed polymers and poly (styrene sulfonate). The solubility and thermal stability of interpolymeric complexes were investigated.
1993, 4(5): 391-392
Abstract:
Additions of diethyl phosphite to α-nitroalkenes followed by the introduction of trimethylchlorosilane and an activated alkene, gave the corresponding title compounds via regioselective 1,3-dipolar cycloaddition in moderate yield.
Additions of diethyl phosphite to α-nitroalkenes followed by the introduction of trimethylchlorosilane and an activated alkene, gave the corresponding title compounds via regioselective 1,3-dipolar cycloaddition in moderate yield.
1993, 4(5): 393-394
Abstract:
(±)Lespedezaflavanone E, 6, 8, 3'-tri(γ,γ-dimethylallyl)-5, 7, 2', 4'-tetrahydroxy-flavanone, has been synthesized by the condensation of 3, 5-di(γ,γ-dimethylallyl)-4, 6-dimethoxymethoxy-2-hydroxyacetophenone and 2, 4-dimethoxymethoxy-3-(γ,γ-dimethylallyl)-benzaldehyde followed by cyclization and demethoxymethylation.
(±)Lespedezaflavanone E, 6, 8, 3'-tri(γ,γ-dimethylallyl)-5, 7, 2', 4'-tetrahydroxy-flavanone, has been synthesized by the condensation of 3, 5-di(γ,γ-dimethylallyl)-4, 6-dimethoxymethoxy-2-hydroxyacetophenone and 2, 4-dimethoxymethoxy-3-(γ,γ-dimethylallyl)-benzaldehyde followed by cyclization and demethoxymethylation.
1993, 4(5): 395-398
Abstract:
The dl-form of the sex pheromone of Japanese beetle and the trail pheromone of Bontebok were synthesised in high purity of (Z)-olefinic configuration. The key step of the syntheses of compounds (1) and (2) involved stereospecific addition of n-alkyl cuprates to acetylene followed by addition of vinyl cuprates to aldehyde (7) and 3-buten-2-one.
The dl-form of the sex pheromone of Japanese beetle and the trail pheromone of Bontebok were synthesised in high purity of (Z)-olefinic configuration. The key step of the syntheses of compounds (1) and (2) involved stereospecific addition of n-alkyl cuprates to acetylene followed by addition of vinyl cuprates to aldehyde (7) and 3-buten-2-one.
1993, 4(5): 399-402
Abstract:
Two peptide analogs H-Tyr-Thr-Pro-Arg-Lys-OH (1) and H-Tyr-Thr-Pro-Phe-Lys-OH (2) were prepared successfully by the technique of simultaneous multiple peptides synthesis(SMPS) on a single resin support. The profiles of HPLC and amino acid analysis indicated that the purity of 1 and 2 was satisfactory. The average yield (74.9%) of each peptide was reasonable. This new technique of SMPS offered significant savings not only in time but in many expensive reagents as well.
Two peptide analogs H-Tyr-Thr-Pro-Arg-Lys-OH (1) and H-Tyr-Thr-Pro-Phe-Lys-OH (2) were prepared successfully by the technique of simultaneous multiple peptides synthesis(SMPS) on a single resin support. The profiles of HPLC and amino acid analysis indicated that the purity of 1 and 2 was satisfactory. The average yield (74.9%) of each peptide was reasonable. This new technique of SMPS offered significant savings not only in time but in many expensive reagents as well.
1993, 4(5): 403-406
Abstract:
Substituted phenoxy acetyl chloride reacted with trimethyl phosphite to form an unexpected substituted phenoxy acetic acid ester, confirmed by 1HNMR, IR and MS. The mechanism suggested is different from that of Arbuzov reaction.
Substituted phenoxy acetyl chloride reacted with trimethyl phosphite to form an unexpected substituted phenoxy acetic acid ester, confirmed by 1HNMR, IR and MS. The mechanism suggested is different from that of Arbuzov reaction.
1993, 4(5): 407-408
Abstract:
Hypophosphorous acid and its salt were found to serve as a new agent for selective reduction of α,β-unsaturated carbonyl compounds under mild reaction conditions.
Hypophosphorous acid and its salt were found to serve as a new agent for selective reduction of α,β-unsaturated carbonyl compounds under mild reaction conditions.
1993, 4(5): 409-410
Abstract:
Photoisomerization of a new polymer: monoesters of polymaleic acid containing naphthalene-azo-anthraquinone groups in side chains at the air-water interface of a Langmuir trough wan detected by recording the development of surface pressure with time. This process wan found to be a first-order reaction and complete within several minutes.
Photoisomerization of a new polymer: monoesters of polymaleic acid containing naphthalene-azo-anthraquinone groups in side chains at the air-water interface of a Langmuir trough wan detected by recording the development of surface pressure with time. This process wan found to be a first-order reaction and complete within several minutes.
1993, 4(5): 411-414
Abstract:
The measured relative rates of halophilic and protophilic attacks (kX/kH) indicate that the rates of halophilic attacks are comparable in magnitude to those of protophilic attacks (deprotonations).
The measured relative rates of halophilic and protophilic attacks (kX/kH) indicate that the rates of halophilic attacks are comparable in magnitude to those of protophilic attacks (deprotonations).
1993, 4(5): 415-416
Abstract:
the catalytic activity of the polymer-bound palladium tetrakis (p-hydroxylphenyl) porphyrin complex (P-THPP-Pd) has been studied. It is found that the polymer catalyst has high selectivity in hydrogenation of olefins, and the rate of initial hydrogen uptake for methyl acrylate is 29.0 (ml H2/min·g cat).
the catalytic activity of the polymer-bound palladium tetrakis (p-hydroxylphenyl) porphyrin complex (P-THPP-Pd) has been studied. It is found that the polymer catalyst has high selectivity in hydrogenation of olefins, and the rate of initial hydrogen uptake for methyl acrylate is 29.0 (ml H2/min·g cat).
1993, 4(5): 417-420
Abstract:
Some K2NiF4-type oxides (A2BO4) exhibited good catalytic activity for oxidative coupling of methane to form ethane and ethylene. The C2 selectivity was well correlated with A-site ion when B-site was Ti4+ ion.
Some K2NiF4-type oxides (A2BO4) exhibited good catalytic activity for oxidative coupling of methane to form ethane and ethylene. The C2 selectivity was well correlated with A-site ion when B-site was Ti4+ ion.
1993, 4(5): 421-422
Abstract:
The transition state (TS) and Intrinsic Reaction Coordinate (IRC) for the titled reaction were traced by means of MCSCF/6-31G (210 configurations). The reaction activation energy of this reaction is 140.2KJ/mol. The reaction rate constants of five temperetures were calculated by CVT involving the tunneling effects.
The transition state (TS) and Intrinsic Reaction Coordinate (IRC) for the titled reaction were traced by means of MCSCF/6-31G (210 configurations). The reaction activation energy of this reaction is 140.2KJ/mol. The reaction rate constants of five temperetures were calculated by CVT involving the tunneling effects.
1993, 4(5): 423-426
Abstract:
Squamostatin-B (1), a new polyketide or acetogenin, has been isolated from Annona squamosa L. (Annonaceae). Its structure and relative atereochemistry were elucidated on the basis of the spectral analyses of 1 and its derivatives, the acetate (2) and mesitoate (3).
Squamostatin-B (1), a new polyketide or acetogenin, has been isolated from Annona squamosa L. (Annonaceae). Its structure and relative atereochemistry were elucidated on the basis of the spectral analyses of 1 and its derivatives, the acetate (2) and mesitoate (3).
1993, 4(5): 427-430
Abstract:
Bacitracin consists of a mixture of several closely related polypeptide antibiotics produced from Bacillus licheniformis.The major component, Bacitracin A, is a cyclic dodecapeptide (Fig, 1), which has strong bacteriocidal effect on the G+ bacteria. The bacteriocidal activity requires the presence of divalent cations such as Zn2+, As we know, the biological function of ploypeptides and proteins are closely related to their three-dimensional structure.
Bacitracin consists of a mixture of several closely related polypeptide antibiotics produced from Bacillus licheniformis.The major component, Bacitracin A, is a cyclic dodecapeptide (Fig, 1), which has strong bacteriocidal effect on the G+ bacteria. The bacteriocidal activity requires the presence of divalent cations such as Zn2+, As we know, the biological function of ploypeptides and proteins are closely related to their three-dimensional structure.
1993, 4(5): 431-434
Abstract:
NMR spectroscopy analysis was introduced to investigate the weak interaction of four 5'-mononucleotides with tryptamide and leucinamide. Assuming a 1:1 complex formation, the association constants were determined by nonlinear regression analysis. The association affinity of 4 mononucleotides with tryptamide decreased in the order: G > A > C > U, indicating that purine bases stack more strongly with tryptamide than pyrimidine bases. But with leucinamide the affinity decreases in the order: G > C > A=U, suggesting an amino acid-anticodonic preferential interaction. The implication of the present data to the origin of genetic code was briefly discussed.
NMR spectroscopy analysis was introduced to investigate the weak interaction of four 5'-mononucleotides with tryptamide and leucinamide. Assuming a 1:1 complex formation, the association constants were determined by nonlinear regression analysis. The association affinity of 4 mononucleotides with tryptamide decreased in the order: G > A > C > U, indicating that purine bases stack more strongly with tryptamide than pyrimidine bases. But with leucinamide the affinity decreases in the order: G > C > A=U, suggesting an amino acid-anticodonic preferential interaction. The implication of the present data to the origin of genetic code was briefly discussed.
1993, 4(5): 435-438
Abstract:
A fluorimetric method for the determination of tyrosine in serum was proposed. The fluoriscence intensity is a linear function of tyrosine content in the range 0-1.44ug/ml. The percentage of recovery was satisfactory.
A fluorimetric method for the determination of tyrosine in serum was proposed. The fluoriscence intensity is a linear function of tyrosine content in the range 0-1.44ug/ml. The percentage of recovery was satisfactory.
1993, 4(5): 439-440
Abstract:
A method which involves conversion of carboxylic acids to corresponding hydrocarbons and determination of high-resoiution mass spectrometry has been applied to the analysis of petroleum acids in Dushanzi distillate and resulted in compound class identification of petroleum acids which have not been reported previously in Xinjiang petroleum.
A method which involves conversion of carboxylic acids to corresponding hydrocarbons and determination of high-resoiution mass spectrometry has been applied to the analysis of petroleum acids in Dushanzi distillate and resulted in compound class identification of petroleum acids which have not been reported previously in Xinjiang petroleum.
1993, 4(5): 441-444
Abstract:
A new type of macro-micro-macro triple electrode is fabricated. The kinetic equation is obtained by using the decrease in collection current to determine the kinetic constant of homogeneous catalytic reaction, the method can be used to study homogeneous chemical reaction with any magnitude of kinetic constant, and overcomes the disadvantages that the microelectrode is only suitable for fast catalytic reaction.
A new type of macro-micro-macro triple electrode is fabricated. The kinetic equation is obtained by using the decrease in collection current to determine the kinetic constant of homogeneous catalytic reaction, the method can be used to study homogeneous chemical reaction with any magnitude of kinetic constant, and overcomes the disadvantages that the microelectrode is only suitable for fast catalytic reaction.
1993, 4(5): 445-448
Abstract:
The present paper describes experiments aimed at delineating significant chemical characteristics of electrochemical reactions in polymeric solutions, including how rigid solvent environments affect mass transport rates, and also discusses the possibility that the microelectrode coated with poly (ethylene oxide)(PEO) film can be used as gas sensor.
The present paper describes experiments aimed at delineating significant chemical characteristics of electrochemical reactions in polymeric solutions, including how rigid solvent environments affect mass transport rates, and also discusses the possibility that the microelectrode coated with poly (ethylene oxide)(PEO) film can be used as gas sensor.
1993, 4(5): 449-450
Abstract:
A schlieren texture with six dark brushes emanating from a point and a closed inversion wall have been observed under polarizing optical microscope in nematic state of a thermotropic aromatic copolyester, which have not been reported so far in the field of liquid crystalline polymers (LCPs).
A schlieren texture with six dark brushes emanating from a point and a closed inversion wall have been observed under polarizing optical microscope in nematic state of a thermotropic aromatic copolyester, which have not been reported so far in the field of liquid crystalline polymers (LCPs).
1993, 4(5): 451-452
Abstract:
The vibrational Raman spectra have been obtained for purified solid films C60. Three bands were observed out of the total of 10 that were theoretically predicted. Some phenomena which may be due to photon-induced oxidation in the vibrational Raman measuring were observed.
The vibrational Raman spectra have been obtained for purified solid films C60. Three bands were observed out of the total of 10 that were theoretically predicted. Some phenomena which may be due to photon-induced oxidation in the vibrational Raman measuring were observed.
1993, 4(5): 453-456
Abstract:
Recently introduced method of 1H-27Al CP/MAS was used to study the dealuminated HZSM-5 zeolite. The experimental result suggests that the resonance signal at ca. 30ppm is an independent signal (not part of a second-order quadrupolar lineshape), probably resulted from 5-coordinated non-framework aluminium (AlNFP). The coincidence of the peaks of 4-coordinated framework (AlF) and 4-coordinated non-framework (AlNF) aluminium at 60ppm was confirmed by 27Al MAS NMR after treating the dealuminated sample with acetylacetone (acac).
Recently introduced method of 1H-27Al CP/MAS was used to study the dealuminated HZSM-5 zeolite. The experimental result suggests that the resonance signal at ca. 30ppm is an independent signal (not part of a second-order quadrupolar lineshape), probably resulted from 5-coordinated non-framework aluminium (AlNFP). The coincidence of the peaks of 4-coordinated framework (AlF) and 4-coordinated non-framework (AlNF) aluminium at 60ppm was confirmed by 27Al MAS NMR after treating the dealuminated sample with acetylacetone (acac).
1993, 4(5): 457-458
Abstract:
Raman peaks at 1951 and 2165 cm-1 can be confirmed further by H2/D2 isotope exchange as H-adspecies on the doubly promoted iron catalyst for ammonia synthesis and are probably ascribed to two terminally adsorbed H-species.
Raman peaks at 1951 and 2165 cm-1 can be confirmed further by H2/D2 isotope exchange as H-adspecies on the doubly promoted iron catalyst for ammonia synthesis and are probably ascribed to two terminally adsorbed H-species.
1993, 4(5): 459-462
Abstract:
The effects of mono-valent cations, Li+, K+, Rb+, Cs+ and NH4+, on 23Na NMR were investigated. It was found that the chemical shifts for Na+ signal shifted downfield with the increase in the relative amounts of monovalent cations. It was suggested that mono-valent cations had competition coordination with Na+ for Dy (PPP) 27-.
The effects of mono-valent cations, Li+, K+, Rb+, Cs+ and NH4+, on 23Na NMR were investigated. It was found that the chemical shifts for Na+ signal shifted downfield with the increase in the relative amounts of monovalent cations. It was suggested that mono-valent cations had competition coordination with Na+ for Dy (PPP) 27-.
1993, 4(5): 463-466
Abstract:
When ammonium sulfate-iron oxide is treated below 573 K, ammonium sulfate can spontaneously desperse on the surface of iron oxide. Simultaneously ammonium sulfate decomposes to some extent. During or after the dispersion, sulfate ion can interact with Fe atom on the surface of iron oxide to form a sort of surface sulfato complex of Fe and thus is transformed from the isolated into the bidentately bound form. Above 573 K the sulfato complex of Fe will gradually decompose with a further increase in temperature.
When ammonium sulfate-iron oxide is treated below 573 K, ammonium sulfate can spontaneously desperse on the surface of iron oxide. Simultaneously ammonium sulfate decomposes to some extent. During or after the dispersion, sulfate ion can interact with Fe atom on the surface of iron oxide to form a sort of surface sulfato complex of Fe and thus is transformed from the isolated into the bidentately bound form. Above 573 K the sulfato complex of Fe will gradually decompose with a further increase in temperature.
1993, 4(5): 467-468
Abstract:
YBa2Cu3-xNbxO7-y superconductors have been prepared. XRD shows that the system remains orthorhombic for all composition. Substitution of Nb5+ for Cu2+ occurs in the Cu (2) sites. The introduction of the Nb5+ ions produces some extra free-electrons. These electrons recombine with the carriers of the system. It makes the mobility and the Hall number of YBa2Cu3-xNbxO7-y decrease and also result in a depression in Tc.
YBa2Cu3-xNbxO7-y superconductors have been prepared. XRD shows that the system remains orthorhombic for all composition. Substitution of Nb5+ for Cu2+ occurs in the Cu (2) sites. The introduction of the Nb5+ ions produces some extra free-electrons. These electrons recombine with the carriers of the system. It makes the mobility and the Hall number of YBa2Cu3-xNbxO7-y decrease and also result in a depression in Tc.
1993, 4(5): 469-470
Abstract:
The title complex [Co(TPPO)4] [Co(NCS)aTPPO]2 (TPPO=triphenylphosphine oside) was prepared by solvent evaporation method. Its crystal structure was determined by x-ray diffraction method. The crystal is rhombohedral with space group R3. The unit cell parameters are presented and the structure has been refined to a final R of 0.064.
The title complex [Co(TPPO)4] [Co(NCS)aTPPO]2 (TPPO=triphenylphosphine oside) was prepared by solvent evaporation method. Its crystal structure was determined by x-ray diffraction method. The crystal is rhombohedral with space group R3. The unit cell parameters are presented and the structure has been refined to a final R of 0.064.
