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1991 Volume 2 Issue 1
1991, 2(1): 1-2
Abstract:
Ten endo-α-substituted-bicyclo[2.2.2]octenyl (and octanyl) methanols were synthesized, their odors were evaluated.
Ten endo-α-substituted-bicyclo[2.2.2]octenyl (and octanyl) methanols were synthesized, their odors were evaluated.
1991, 2(1): 3-6
Abstract:
In the presence of tetrazole, 2'-substituted nucleosidesreacted stereospecifically with n-BuOPIN (C2H5) 2I2 to nucleoside 3', 5'-cyclophosphites with avial n-Buo group. The stereochemistry of oxidation of cyclophosphite was investigated.
In the presence of tetrazole, 2'-substituted nucleosidesreacted stereospecifically with n-BuOPIN (C2H5) 2I2 to nucleoside 3', 5'-cyclophosphites with avial n-Buo group. The stereochemistry of oxidation of cyclophosphite was investigated.
1991, 2(1): 7-8
Abstract:
A precursor 9 of isosarcophytol-A (1) was prepared from (E, E)-farnesol (3) through 6 steps.
A precursor 9 of isosarcophytol-A (1) was prepared from (E, E)-farnesol (3) through 6 steps.
1991, 2(1): 9-12
Abstract:
Studies of direction of photoisomerization of retinal, retinonitrile, α-retinonitrile and a trienenitrile analog in different solvents with varying wave-lengths of excitation and reaction temperature led to the conclusion that the well known solvent dependent photochemistry of retinoids is due to selective excitation of the hydrogen bonded species.
Studies of direction of photoisomerization of retinal, retinonitrile, α-retinonitrile and a trienenitrile analog in different solvents with varying wave-lengths of excitation and reaction temperature led to the conclusion that the well known solvent dependent photochemistry of retinoids is due to selective excitation of the hydrogen bonded species.
1991, 2(1): 13-14
Abstract:
In addition to 2-deoxycrustecdysone (1), we isolated and identi-fied two new natural moulting hormones-2-deoxy-3-epicrustecdysone (2) and 2-deoxycrustecdysone-3-O-β-D-glucopyranoside (3) from the roots of Tino-spora capillipes, it is the first time to get ecdysteroids from this genus.
In addition to 2-deoxycrustecdysone (1), we isolated and identi-fied two new natural moulting hormones-2-deoxy-3-epicrustecdysone (2) and 2-deoxycrustecdysone-3-O-β-D-glucopyranoside (3) from the roots of Tino-spora capillipes, it is the first time to get ecdysteroids from this genus.
1991, 2(1): 15-16
Abstract:
Five pectic polysaccharides CPA-CPE were purified from the pollen of Codonopsis Pilosula [Franch] Nannf. They are all composed of L-arabinofuranosyl and D-galactopyranosyl residues. The results of methylation analysis and periodate oxidation and Smith degradation revealed that CPA was a highly branched arabinogalactan probably with a backbone of (1→6) D-Galp. Electron micrograph of CPA showed a secondary structural feature of a string of pearls.
Five pectic polysaccharides CPA-CPE were purified from the pollen of Codonopsis Pilosula [Franch] Nannf. They are all composed of L-arabinofuranosyl and D-galactopyranosyl residues. The results of methylation analysis and periodate oxidation and Smith degradation revealed that CPA was a highly branched arabinogalactan probably with a backbone of (1→6) D-Galp. Electron micrograph of CPA showed a secondary structural feature of a string of pearls.
1991, 2(1): 17-18
Abstract:
Salvianolic acid G, a caffeic acid dimer with a novel tetracyclic skeleton was isolated from the roots of Salvia miltiorrhiza. Its structure was elucidated by chemical and spectral analysis, especially by 2D NMR analysis.
Salvianolic acid G, a caffeic acid dimer with a novel tetracyclic skeleton was isolated from the roots of Salvia miltiorrhiza. Its structure was elucidated by chemical and spectral analysis, especially by 2D NMR analysis.
1991, 2(1): 19-22
Abstract:
A reliable method is described for the detection of amitoride, triamterene. canrenone and spironolactone in human urine using GC-MS analysis after trimethytsitytation. The mass spectrometric and metabotic features of the compounds are discussed.
A reliable method is described for the detection of amitoride, triamterene. canrenone and spironolactone in human urine using GC-MS analysis after trimethytsitytation. The mass spectrometric and metabotic features of the compounds are discussed.
1991, 2(1): 23-26
Abstract:
Rapid simultaneous determination of chlorophyll a and chlorophyll b by reverse variable-angle synchronous spectrofluorimetry has been studied on a laboratory-constructed microcomputer-controlled versatile spectrofluorimeter. A method in estimation of scan parameters for the determination of two-component system by variable-angle synchronous spectrofluorimetry has been suggested.
Rapid simultaneous determination of chlorophyll a and chlorophyll b by reverse variable-angle synchronous spectrofluorimetry has been studied on a laboratory-constructed microcomputer-controlled versatile spectrofluorimeter. A method in estimation of scan parameters for the determination of two-component system by variable-angle synchronous spectrofluorimetry has been suggested.
1991, 2(1): 27-28
Abstract:
The electroanalytical behaviour of xanthophyll was studied by differential pulse polarography and cyclic voltammetry. The reduction wave of xanthophyll at-0.92V (v. s. Ag/AgCl) in 1.25% tetrabutyl ammonium chloride solution (TBAC) was found for the first time. The optimum conditions for the determination of xanthophyll by DPP were established. The results from the application of cyclic voltammetry to study electrode process behaviour showed that the electrode reaction of xanthophyll at a hanging mercury electrode is quasi-reversible reaction.
The electroanalytical behaviour of xanthophyll was studied by differential pulse polarography and cyclic voltammetry. The reduction wave of xanthophyll at-0.92V (v. s. Ag/AgCl) in 1.25% tetrabutyl ammonium chloride solution (TBAC) was found for the first time. The optimum conditions for the determination of xanthophyll by DPP were established. The results from the application of cyclic voltammetry to study electrode process behaviour showed that the electrode reaction of xanthophyll at a hanging mercury electrode is quasi-reversible reaction.
1991, 2(1): 29-30
Abstract:
A method for the determination of Mylis by coulometric titration was developed. The titration was carried out in a mixture of 1 mol/L KBr-2 mol/L HCl (1:1) and bromine was generated at the anode, Mylis reacted with one mole of bromine with a n value of 2. The advantages of this method are simple and rapid, it can be used to analyze small amount of sample.
A method for the determination of Mylis by coulometric titration was developed. The titration was carried out in a mixture of 1 mol/L KBr-2 mol/L HCl (1:1) and bromine was generated at the anode, Mylis reacted with one mole of bromine with a n value of 2. The advantages of this method are simple and rapid, it can be used to analyze small amount of sample.
1991, 2(1): 31-34
Abstract:
A multidimensional gas chromatographic technique with heartcutting was used for the determination of complex isomeric mixtures of tetra-chlorodibenzo-p-dioxins (TCDDs) which could not be completely separated on a single capillary column. When using so-called heartcutting technique, only the interested single peak or section of the fraction eluting from the first column was transferred onto the second column with different stationary phase. Flame ionization detection was used as the monitor detector and electron capture detection as the main detector. This arrangement offers complete separation and avoids interference of the possible remained chlorinated solvents. The separation power of multi-dimensional GC was demonstrated by the determination of TCDD isomers.
A multidimensional gas chromatographic technique with heartcutting was used for the determination of complex isomeric mixtures of tetra-chlorodibenzo-p-dioxins (TCDDs) which could not be completely separated on a single capillary column. When using so-called heartcutting technique, only the interested single peak or section of the fraction eluting from the first column was transferred onto the second column with different stationary phase. Flame ionization detection was used as the monitor detector and electron capture detection as the main detector. This arrangement offers complete separation and avoids interference of the possible remained chlorinated solvents. The separation power of multi-dimensional GC was demonstrated by the determination of TCDD isomers.
1991, 2(1): 35-36
Abstract:
The paper studies the chemical structures of eight synthetic 9-β-D-xylofuranosyl-adenine-8-subatituted amino derivatives, by Fast Atom Bombardment Mass Spectrometry (FAB-MS). FAB-MS spectrum can give the molecular weight information of the samples and inquire into the significant fragments from the samples.
The paper studies the chemical structures of eight synthetic 9-β-D-xylofuranosyl-adenine-8-subatituted amino derivatives, by Fast Atom Bombardment Mass Spectrometry (FAB-MS). FAB-MS spectrum can give the molecular weight information of the samples and inquire into the significant fragments from the samples.
1991, 2(1): 37-40
Abstract:
Sr0.5Ca0.5CuO2 has been synthesized by the solid state reaction. The compound crystallizes in an orthorhombic unit cell, space group D2h17-Cmcm with a=3.444 Å, b=16.11 Å, c=3.868 Å. It decomposes shove 1038℃. Sr0.5Ca0.5CuO2 is a black p-type semiconductor with resistivity 53 Ω·cm at room tempersture.
Sr0.5Ca0.5CuO2 has been synthesized by the solid state reaction. The compound crystallizes in an orthorhombic unit cell, space group D2h17-Cmcm with a=3.444 Å, b=16.11 Å, c=3.868 Å. It decomposes shove 1038℃. Sr0.5Ca0.5CuO2 is a black p-type semiconductor with resistivity 53 Ω·cm at room tempersture.
1991, 2(1): 41-44
Abstract:
With derivative spectrophotometric method, the complexes of lanthanides with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) in the presence of octylphenol poly (ethyleneglycol) ether (TX-100) were studied. It is found that the maximum absorption of fourth-order derivative spectra of the neodymium complex by 4f electron transitions is at 579 (+) nm and 582 (-) nm with molar derivative absorptivities of 5.2×103 l·mol-1·cm-1. The maximum absorption of the zero-order derivative spectra of the complexes for neodymium and praseodymium is at 580nm, the molar absorptivities are 1.47×105 l·mol-1·cm-1 for Nd and 1.26×105 l·mol-1·cm-1for Pr. The component ratio of the complex is Nd:5-Br-PADAP=1:4. Beer's law is obeyed in the range of 0-3.75μg of Nd and Pr in 25ml of solution. The method has been used for the simultaneous determination of Nd and Pr in four synthetic samples and the results obtained are satisfactory.
With derivative spectrophotometric method, the complexes of lanthanides with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) in the presence of octylphenol poly (ethyleneglycol) ether (TX-100) were studied. It is found that the maximum absorption of fourth-order derivative spectra of the neodymium complex by 4f electron transitions is at 579 (+) nm and 582 (-) nm with molar derivative absorptivities of 5.2×103 l·mol-1·cm-1. The maximum absorption of the zero-order derivative spectra of the complexes for neodymium and praseodymium is at 580nm, the molar absorptivities are 1.47×105 l·mol-1·cm-1 for Nd and 1.26×105 l·mol-1·cm-1for Pr. The component ratio of the complex is Nd:5-Br-PADAP=1:4. Beer's law is obeyed in the range of 0-3.75μg of Nd and Pr in 25ml of solution. The method has been used for the simultaneous determination of Nd and Pr in four synthetic samples and the results obtained are satisfactory.
1991, 2(1): 45-46
Abstract:
This paper emphasizes the observation of SERS spectra of imidazole/LiCl in methanol solution at a silver electrode and a qualitative explaination of the relationship between HERS spectra and molecular vibrational modes, and the relationship between SERS spectrum in aqueous and that in nonaqueous system.
This paper emphasizes the observation of SERS spectra of imidazole/LiCl in methanol solution at a silver electrode and a qualitative explaination of the relationship between HERS spectra and molecular vibrational modes, and the relationship between SERS spectrum in aqueous and that in nonaqueous system.
1991, 2(1): 47-50
Abstract:
In our study on the chemistry of ZrCl4-NaBH4, we have found that aldehydes and ketones can be regenerated from acetals and ketals at 30℃ in Et2O in high yield The reaction mechanism was discussed.
In our study on the chemistry of ZrCl4-NaBH4, we have found that aldehydes and ketones can be regenerated from acetals and ketals at 30℃ in Et2O in high yield The reaction mechanism was discussed.
1991, 2(1): 51-54
Abstract:
The structural studies of the telluronium saltrformation between dibutyl telluride and secondary α-bromo compounds and the use of the obtained salts for the olefination of carbonyl compounds were reported.
The structural studies of the telluronium saltrformation between dibutyl telluride and secondary α-bromo compounds and the use of the obtained salts for the olefination of carbonyl compounds were reported.
1991, 2(1): 55-56
Abstract:
The in-situ FTIR spectroscopic results show that a hemi-ketal intermediate may be produced in the electroreduction of benzoquinone or electro-oxidation of benzohydroquinone, which provides a valuable insight into the mechanism of the redox process.
The in-situ FTIR spectroscopic results show that a hemi-ketal intermediate may be produced in the electroreduction of benzoquinone or electro-oxidation of benzohydroquinone, which provides a valuable insight into the mechanism of the redox process.
1991, 2(1): 57-58
Abstract:
A study of the quenching of pyrene fluorescence by a series of alkyltriphenylphosphonium bromides indicated the coiling conformation of ionic surfactant in aqueous solution. Formation of pyrene excimer in cetyltriph-enylphosphonium solution strengthened the conclusion.
A study of the quenching of pyrene fluorescence by a series of alkyltriphenylphosphonium bromides indicated the coiling conformation of ionic surfactant in aqueous solution. Formation of pyrene excimer in cetyltriph-enylphosphonium solution strengthened the conclusion.
1991, 2(1): 59-62
Abstract:
In this paper, we report the deductive formula used for the method of dual-wavelength corresponding solutions under condition of having ligand interference and the stability constants of three new coordination compounds [AuL2]+ determined with this method. The stability of the three compounds, the necessity of controlling pH in experimental systems and the advantage of this method are discussed in detail.
In this paper, we report the deductive formula used for the method of dual-wavelength corresponding solutions under condition of having ligand interference and the stability constants of three new coordination compounds [AuL2]+ determined with this method. The stability of the three compounds, the necessity of controlling pH in experimental systems and the advantage of this method are discussed in detail.
1991, 2(1): 63-64
Abstract:
A very simple method to calculate resonance energies of conjugated hydrocarbons by counting carbon numbers was introduced.
A very simple method to calculate resonance energies of conjugated hydrocarbons by counting carbon numbers was introduced.
1991, 2(1): 65-66
Abstract:
The inversion reaction of hydroxy lamine was investigated by using the ab initio intrinsic reaction coordinate (IRC) method with 4-31G basis set. Our results indicate that the ∠H1NO changes arastically in the vicinity of the transition state while the other bond angles and bond lengths change little throughout the reaction process.
The inversion reaction of hydroxy lamine was investigated by using the ab initio intrinsic reaction coordinate (IRC) method with 4-31G basis set. Our results indicate that the ∠H1NO changes arastically in the vicinity of the transition state while the other bond angles and bond lengths change little throughout the reaction process.
SYNTHESIS AND CHARACTERIZATION OF A SERIES OF NOVEL INORGANIC MICROPOROUS CRYSTALS,BePO4-CIn（n=4-7）.
1991, 2(1): 67-70
Abstract:
A series of novet beryllophosphate zeolites, named BePO4-CIn (n=4-7), are synthesized hydrothermally and characterized with X-ray powder diffraction, IR spectra, SEM, thermat analysis and ion-exchange.
A series of novet beryllophosphate zeolites, named BePO4-CIn (n=4-7), are synthesized hydrothermally and characterized with X-ray powder diffraction, IR spectra, SEM, thermat analysis and ion-exchange.
1991, 2(1): 71-72
Abstract:
The complexes of meso-tetrasubstituted phenylporphyrin with Yttrium acetylacetonate were prepared by reaction of Y (acac) 33H2O with H2 (g) Tpp and were characterized by elemental analyses, ultra-violet, infrared spectra and thermal analyses.
The complexes of meso-tetrasubstituted phenylporphyrin with Yttrium acetylacetonate were prepared by reaction of Y (acac) 33H2O with H2 (g) Tpp and were characterized by elemental analyses, ultra-violet, infrared spectra and thermal analyses.
1991, 2(1): 73-74
Abstract:
There are many reports on the study of boiling point of paraffins, but less work has been done about those of alkylhalides. Recently, J. Correia
There are many reports on the study of boiling point of paraffins, but less work has been done about those of alkylhalides. Recently, J. Correia
1991, 2(1): 75-76
Abstract:
The photovoltaic behaviours of thin films of novel photosensitizer consisting of covalently linked phthalocyanine (Pc) and anthraquinone (AQ) were studied in 0.1mol/L Na2SO4 solution. The results revealed that the higher photovoltage and photocurrent have been obtained due to light induced intra-molecules fast electron transfer in linked Pc-AQ compounds. The effects of different spacer chains between Pc and AQ molecules on photovoltaic behaviours were also discussed.
The photovoltaic behaviours of thin films of novel photosensitizer consisting of covalently linked phthalocyanine (Pc) and anthraquinone (AQ) were studied in 0.1mol/L Na2SO4 solution. The results revealed that the higher photovoltage and photocurrent have been obtained due to light induced intra-molecules fast electron transfer in linked Pc-AQ compounds. The effects of different spacer chains between Pc and AQ molecules on photovoltaic behaviours were also discussed.
1991, 2(1): 77-80
Abstract:
The photoelectrochemical behavior of polyaniline (PAn) film was studied in aqueous electrolyte solution containing Fe (CN) 63-/Fe (CN) 64- redox couple. It was found that PAn films possess the properties of p-type semiconducter and a cathodic photocurrent as high as 700μA/cm2 was observed when irradiated under polychromatic light of 100mW/cm2.
The photoelectrochemical behavior of polyaniline (PAn) film was studied in aqueous electrolyte solution containing Fe (CN) 63-/Fe (CN) 64- redox couple. It was found that PAn films possess the properties of p-type semiconducter and a cathodic photocurrent as high as 700μA/cm2 was observed when irradiated under polychromatic light of 100mW/cm2.
1991, 2(1): 81-84
Abstract:
A series of novel aluminophosphates, named AlPO4-CJn (n=2-5), has been synthesized hydrothermally from R-Al2O3-P2O5-H2O systems (R=organic amine molecules), and characterized by means of X-ray powder diffraction, infrared, SEM, XPS, composition and thermal analyses.
A series of novel aluminophosphates, named AlPO4-CJn (n=2-5), has been synthesized hydrothermally from R-Al2O3-P2O5-H2O systems (R=organic amine molecules), and characterized by means of X-ray powder diffraction, infrared, SEM, XPS, composition and thermal analyses.
1991, 2(1): 85-86
Abstract:
In this letter, Fe2O3 UFP (Ultrafine Particles) hydrosol and organosol with high third order optical nonlinear susceptibility (3) have been reported for the first time. The surfacial modification of Fe2O3 UFP with dodecylbenzenesulfonate ions (DBS) can enhance the nonlinear optical response through interfacial confinement of electron motion. The involved mechanism is discussed.
In this letter, Fe2O3 UFP (Ultrafine Particles) hydrosol and organosol with high third order optical nonlinear susceptibility (3) have been reported for the first time. The surfacial modification of Fe2O3 UFP with dodecylbenzenesulfonate ions (DBS) can enhance the nonlinear optical response through interfacial confinement of electron motion. The involved mechanism is discussed.
1991, 2(1): 87-88
Abstract:
The dismutation kinetics of superoxide anion by copper complex of 1, 4, 7, 10-tetranza-cyctotridecane-11, 13-dione was studied by pulse radiolysis. The dismutation rate constants at various pH and concentration of complex were obtained.
The dismutation kinetics of superoxide anion by copper complex of 1, 4, 7, 10-tetranza-cyctotridecane-11, 13-dione was studied by pulse radiolysis. The dismutation rate constants at various pH and concentration of complex were obtained.
1991, 2(1): 89-90
Abstract:
A New electronegativity topological index is defined and used to correlate with properties of MX, MX2, MX3, MX4.
A New electronegativity topological index is defined and used to correlate with properties of MX, MX2, MX3, MX4.
1991, 2(1): 91-94
Abstract:
Decay frequency (DF) spectra are defined as spectral distribution of decay constants with oscillatory frequency as linewidth contributor. A mathematical strategy of integral transformation to construct DF spectra is reported. DF spectra are complementary to Fourier spectra.
Decay frequency (DF) spectra are defined as spectral distribution of decay constants with oscillatory frequency as linewidth contributor. A mathematical strategy of integral transformation to construct DF spectra is reported. DF spectra are complementary to Fourier spectra.
