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1993 Volume 4 Issue 11
1993, 4(11): 941-942
Abstract:
The intermotecular coupling reaction of esters with diaryl ketones induced by titanium tetrachtoride and zinc powder was studied.
The intermotecular coupling reaction of esters with diaryl ketones induced by titanium tetrachtoride and zinc powder was studied.
1993, 4(11): 943-946
Abstract:
Low-valent titanium reagent prepared from titanium tetrachloride and zinc was empolyed to induce the coupling reaction of thiocyanates with tetrahydrofuran yield alkyl 4-hydroxy butyl sulfide and isocyanate yield substituted urea.
Low-valent titanium reagent prepared from titanium tetrachloride and zinc was empolyed to induce the coupling reaction of thiocyanates with tetrahydrofuran yield alkyl 4-hydroxy butyl sulfide and isocyanate yield substituted urea.
1993, 4(11): 947-948
Abstract:
A potent antineoplastic tetrahydrochlorovulone 3 was synthesized with retro-Diels Alder reaction as a key step.
A potent antineoplastic tetrahydrochlorovulone 3 was synthesized with retro-Diels Alder reaction as a key step.
1993, 4(11): 949-950
Abstract:
Racemic O-methyl O-pheayl thiophosphoric acid 1 has been successfully resolved through its quinine and brucine salts in methanol solution by fractional crystallization. The absolute configurations of the optically active 1 have been established as (+)-R-1 and (-)-S-1 by chemical correlation.
Racemic O-methyl O-pheayl thiophosphoric acid 1 has been successfully resolved through its quinine and brucine salts in methanol solution by fractional crystallization. The absolute configurations of the optically active 1 have been established as (+)-R-1 and (-)-S-1 by chemical correlation.
1993, 4(11): 951-952
Abstract:
This paper reports abnormal cyclization in the formation of some coumarins.
This paper reports abnormal cyclization in the formation of some coumarins.
1993, 4(11): 953-956
Abstract:
Reaction of p-t-butylcalix[6]arene with ethylene oxide gives a water soluble host compound with a hydrophobic cavity and it can include organic molecules and ions in aqueous solution.
Reaction of p-t-butylcalix[6]arene with ethylene oxide gives a water soluble host compound with a hydrophobic cavity and it can include organic molecules and ions in aqueous solution.
1993, 4(11): 957-958
Abstract:
This paper relates to the structural elucidation of a new cycloartane triterpene glycoside, namely cimiside E (1), which was newly isolatea from the rnizomes of Cimicifuga foetida L.. Based on spectral evidence, its structure has been established as 25-anhydrocimigenol-3-O-β-D-xylopyranoside (23R, 24S).
This paper relates to the structural elucidation of a new cycloartane triterpene glycoside, namely cimiside E (1), which was newly isolatea from the rnizomes of Cimicifuga foetida L.. Based on spectral evidence, its structure has been established as 25-anhydrocimigenol-3-O-β-D-xylopyranoside (23R, 24S).
1993, 4(11): 959-962
Abstract:
The active intermediate"carbon radical" was detected by the spin-trapping reagent (POBN)① during the debromination of Ph2CHBr in the presence of viologen derivatives as electron-transfer catalysts (ETC).
The active intermediate"carbon radical" was detected by the spin-trapping reagent (POBN)① during the debromination of Ph2CHBr in the presence of viologen derivatives as electron-transfer catalysts (ETC).
1993, 4(11): 963-964
Abstract:
The localized molecular orbitals for typical bowl-shaped circulenes are obtained by the use of INDO-LMO method. It is found that these bowl-shaped circulenes with strained π-electron systems are still aromatic and the rim π-bonds with larger localization form reactive regions for formation of buckminsterfullerene.
The localized molecular orbitals for typical bowl-shaped circulenes are obtained by the use of INDO-LMO method. It is found that these bowl-shaped circulenes with strained π-electron systems are still aromatic and the rim π-bonds with larger localization form reactive regions for formation of buckminsterfullerene.
1993, 4(11): 965-968
Abstract:
Adsorption-desorption kinetics of CO and H2 on Ni surface were studied with molecular beam relaxation spectrometry. It is found that there are two adsorbed states in the substrate temperature range 330Kaα=14.6kJ/mol, Edα=49.3kJ/mol; Eaβ=68.6kJ/mol, Edβ=200.6kJ/mol. It is shown that there are two adsorbed states in the low (350K 2/Ni system. These results can be explained by a direct dissociative model. Their kinetic parameters:Edl=26.3kJ/mol, Edh=103.7kJ/mol.
Adsorption-desorption kinetics of CO and H2 on Ni surface were studied with molecular beam relaxation spectrometry. It is found that there are two adsorbed states in the substrate temperature range 330K
1993, 4(11): 969-970
Abstract:
Methane conversions at lower temperature were studied. The aetivity of Y2O3 sample at 823K was fairly high with some formation of C2H4 and C2H6, the catalysts based on alkaline earth oxides and yttria would give better results. The influences of flux ratio, space velocity, and reaction temperature were also discussed.
Methane conversions at lower temperature were studied. The aetivity of Y2O3 sample at 823K was fairly high with some formation of C2H4 and C2H6, the catalysts based on alkaline earth oxides and yttria would give better results. The influences of flux ratio, space velocity, and reaction temperature were also discussed.
1993, 4(11): 971-974
Abstract:
The denaturational behaviour of bovine β-lactoglobulin B has been studied in solutions containing guanidine hydrochloride by differential scanning calorimetry. The experiments have shown that complete peaks of cold denaturation can be recorded also in high concentration of protein solutions. The cold denaturation and the renaturation of the protein are reproducible, but the thermal denaturation is irreversible. The activation energy of thermal denaturation calculated is about 285 kJ/mol.
The denaturational behaviour of bovine β-lactoglobulin B has been studied in solutions containing guanidine hydrochloride by differential scanning calorimetry. The experiments have shown that complete peaks of cold denaturation can be recorded also in high concentration of protein solutions. The cold denaturation and the renaturation of the protein are reproducible, but the thermal denaturation is irreversible. The activation energy of thermal denaturation calculated is about 285 kJ/mol.
1993, 4(11): 975-978
Abstract:
A method for simultaneously analyzing altemariol (AOH), altemariol monomethyl ether (AME) and zearalenone (ZEA) by particle beam LC/MS was established, LC separation was accompiished with a solvent system of methanol and water (80:20 v/v). The followed particle beam LC/MS analysis gave searchable spectra of AOH. AME and ZEA. Application of this technique to analysis of an alternaria culture confirmed the presence of AOH and AME.
A method for simultaneously analyzing altemariol (AOH), altemariol monomethyl ether (AME) and zearalenone (ZEA) by particle beam LC/MS was established, LC separation was accompiished with a solvent system of methanol and water (80:20 v/v). The followed particle beam LC/MS analysis gave searchable spectra of AOH. AME and ZEA. Application of this technique to analysis of an alternaria culture confirmed the presence of AOH and AME.
1993, 4(11): 979-982
Abstract:
A quasi-reversible reduction peak of a fentanyl derivative DNPME is found by cyclic voltammetry at Hg electrode. Epc=-1.58 V (vs. Ag/AgCl). The cathodic peak shows adsorptive characteristics. The adsorbed species is DNPME neutral molecule. The method for measuring trace amount of DNPME by adsorptive stripping voltammetry is established.
A quasi-reversible reduction peak of a fentanyl derivative DNPME is found by cyclic voltammetry at Hg electrode. Epc=-1.58 V (vs. Ag/AgCl). The cathodic peak shows adsorptive characteristics. The adsorbed species is DNPME neutral molecule. The method for measuring trace amount of DNPME by adsorptive stripping voltammetry is established.
1993, 4(11): 983-984
Abstract:
Compared with the conventionally used i=iosin ωt alternating current, using asymmetric triangular and pulse wave as input signals can greatly enhance the incision's sensitivity of "dE/dt-E" oscillogram.
Compared with the conventionally used i=iosin ωt alternating current, using asymmetric triangular and pulse wave as input signals can greatly enhance the incision's sensitivity of "dE/dt-E" oscillogram.
1993, 4(11): 985-988
Abstract:
The indirect voltammetric determination of trace sulfate (2.0×10-6~4.0×10-5 mol/L) with the adsorptive complex wave of lead (Ⅱ)-tetrakis (4-trimethylammonium phenyl) porphyrin (PbTTMAPP) is reported. This method has been used for the analysis of natural waters with satisfactory results.
The indirect voltammetric determination of trace sulfate (2.0×10-6~4.0×10-5 mol/L) with the adsorptive complex wave of lead (Ⅱ)-tetrakis (4-trimethylammonium phenyl) porphyrin (PbTTMAPP) is reported. This method has been used for the analysis of natural waters with satisfactory results.
1993, 4(11): 989-992
Abstract:
Rare earth chelates of benzoyl urea derivatives were prepared in ethanol and fluorescence spectra of these chelates were studied in detail. A composition of[RE (BU) 3Phen] (NO3)3 was obtained. Correlation between chemical properties of ligands, chelates and spectroscopy was discussed. Intramolecular energy transfer in rare earth chelates was explained.
Rare earth chelates of benzoyl urea derivatives were prepared in ethanol and fluorescence spectra of these chelates were studied in detail. A composition of[RE (BU) 3Phen] (NO3)3 was obtained. Correlation between chemical properties of ligands, chelates and spectroscopy was discussed. Intramolecular energy transfer in rare earth chelates was explained.
1993, 4(11): 993-994
Abstract:
The electrochemical potentiokinetic reactivation technique (EPR) and the potentiostatic pulse technique (PPT) have been used to detect sensitization of austenitic stainless steel. Compared with EPR, PPT has some advantages such as it can be conducted at greater speed and with less destruction, etc. The sensitivity of PPT can be improved by altering t1/t2 in a certain range and it will favour the detection of the specimen with lower degree of sensitization.
The electrochemical potentiokinetic reactivation technique (EPR) and the potentiostatic pulse technique (PPT) have been used to detect sensitization of austenitic stainless steel. Compared with EPR, PPT has some advantages such as it can be conducted at greater speed and with less destruction, etc. The sensitivity of PPT can be improved by altering t1/t2 in a certain range and it will favour the detection of the specimen with lower degree of sensitization.
1993, 4(11): 995-998
Abstract:
Described here are the fabrication and characterization of carbon fiber cylinder ultramicroelectrodes with cylinder length of less than 100 μm, total tip diameter of several hundreds nanometers. The electrodes have been fabricated by direct etching of carbon fiber using an ion beam thinner. Optical microscopy, scanning electron microscopy (SEM), cyclic voltammetry have been employed to characterize those electrodes. The experimental results obtained indicate the electrodes can be used for in vivo detection of neurotransmitters such as dopamine, 5-hydroxytryptamine in a single cell.
Described here are the fabrication and characterization of carbon fiber cylinder ultramicroelectrodes with cylinder length of less than 100 μm, total tip diameter of several hundreds nanometers. The electrodes have been fabricated by direct etching of carbon fiber using an ion beam thinner. Optical microscopy, scanning electron microscopy (SEM), cyclic voltammetry have been employed to characterize those electrodes. The experimental results obtained indicate the electrodes can be used for in vivo detection of neurotransmitters such as dopamine, 5-hydroxytryptamine in a single cell.
1993, 4(11): 999-1002
Abstract:
Amorphous Ti0.88Ni1.00 and Ti1.69Ni1.00 alloy films are prepared by means of ion beam sputtering using TiNi and Ti2Ni alloy targets, respectively. Their hydrogen absorption properties are investigated by a galvanostatic method. The results show that the discharge capacity of the Ti1.69Ni1.00 sample is higher than that of the Ti0.88Ni1.00 sample. And the film electrodes have high durability and long cycle life.
Amorphous Ti0.88Ni1.00 and Ti1.69Ni1.00 alloy films are prepared by means of ion beam sputtering using TiNi and Ti2Ni alloy targets, respectively. Their hydrogen absorption properties are investigated by a galvanostatic method. The results show that the discharge capacity of the Ti1.69Ni1.00 sample is higher than that of the Ti0.88Ni1.00 sample. And the film electrodes have high durability and long cycle life.
1993, 4(11): 1003-1006
Abstract:
A new kind of amphiphilic copolymer was synthesized with azo bond functional side chains, and elementary studies about formation of I, B film, UV-visible spectra and photoelectrical properties of multilayers of this kind of amphiphilic copolymer were reported.
A new kind of amphiphilic copolymer was synthesized with azo bond functional side chains, and elementary studies about formation of I, B film, UV-visible spectra and photoelectrical properties of multilayers of this kind of amphiphilic copolymer were reported.
1993, 4(11): 1007-1010
Abstract:
Based on ID ROGM, d33 of poled films can be estimated from orientation factor3θ>. In this letter, a direct expression3θ>=√0.6φ,which is suitable for all used poling methods, is introduced.Order parameter φ can be measured by UV-Vis absorption spectra or polarized IR spectra of poled films.
Based on ID ROGM, d33 of poled films can be estimated from orientation factor
1993, 4(11): 1011-1012
Abstract:
The cation-conductive blends plasticized with propylene carbonate were prepared. The blends exhibited good mechanical strength and single-cation conduction over a wide range of plasticizer composition. The plasticizer not only increases the conductivity of the blends but also decreases the electrochemical interface resistance between the blend and lithium electrode. The carrier in the blends obviously grows in number.
The cation-conductive blends plasticized with propylene carbonate were prepared. The blends exhibited good mechanical strength and single-cation conduction over a wide range of plasticizer composition. The plasticizer not only increases the conductivity of the blends but also decreases the electrochemical interface resistance between the blend and lithium electrode. The carrier in the blends obviously grows in number.
1993, 4(11): 1013-1016
Abstract:
Crystal growth habits of O-Dicyanovinyl anisole (DIVA) in organic solvents are described.
Crystal growth habits of O-Dicyanovinyl anisole (DIVA) in organic solvents are described.
1993, 4(11): 1017-1020
Abstract:
The electronic structure of Agn and Aun (n=2, 3, 4) calculated by DV-Xα method, are different each other, and the ionization potentials of Agn and Aun as a function of cluster size n exhibit an interesting "saw-tooth" behavior. The interactions between atom Ag-Ag and Au-Au in Ag2, Au2 for different bond length are analyzed. The DOS of the orbitals shows those interactions directly.
The electronic structure of Agn and Aun (n=2, 3, 4) calculated by DV-Xα method, are different each other, and the ionization potentials of Agn and Aun as a function of cluster size n exhibit an interesting "saw-tooth" behavior. The interactions between atom Ag-Ag and Au-Au in Ag2, Au2 for different bond length are analyzed. The DOS of the orbitals shows those interactions directly.
1993, 4(11): 1021-1024
Abstract:
l, l'-biisoquinoline can coordinate with ruthenfum (Ⅱ) to form a new series of mononuclear complexes and the electronic absorption of these complexes were measured and reasonably assigned.
l, l'-biisoquinoline can coordinate with ruthenfum (Ⅱ) to form a new series of mononuclear complexes and the electronic absorption of these complexes were measured and reasonably assigned.
1993, 4(11): 1025-1028
Abstract:
Reaction of ferrocenoyl chloride with[EtaNH] [(μ-CO) (μ-RS) Fe2=(CO)6] complexes gave bridging ferrocenoyl complexes (μ-FcCO)(μ-RS) Fe2 (CO)6 (Fc=ferrocenyl, R=Et, i-Pr, n-Bu, t-Bu, Ph). The structures of all new complexes were characterised by 1HNMR, IR and MS.
Reaction of ferrocenoyl chloride with[EtaNH] [(μ-CO) (μ-RS) Fe2=(CO)6] complexes gave bridging ferrocenoyl complexes (μ-FcCO)(μ-RS) Fe2 (CO)6 (Fc=ferrocenyl, R=Et, i-Pr, n-Bu, t-Bu, Ph). The structures of all new complexes were characterised by 1HNMR, IR and MS.
1993, 4(11): 1029-1030
Abstract:
A novel three dimensional network complex polymer[Cu4 (oxen)2(N3)3]n(ClO4)n·2nH2O, where oxen is N, N'-bis(2-aminoethyl) oxamide dianion, has been synthesized. It crystallizes in triclinic system, space group P1, with a=11.486 (2), b=11.706 (3), c=12.291 (3)Å, α=77.42 (2), β=67.59 (2), γ=77.96 (2)°, and z=2. The least-square refinements converged at R=0.047, with 3416 observed unique reflections. The complex has a pronounced three-dimensional character and can be viewed as the tetranuclear asymmetric repeating units through inversion and translation operations to extend a three-dimensional network. The structure of Cu4 asymmetric unit consists of two square planar and two square pyramidal Cu central atoms linked by both azide ligands in end-on and end-to-end bonding modes, and oxamidate bridge in trans conformation.
A novel three dimensional network complex polymer[Cu4 (oxen)2(N3)3]n(ClO4)n·2nH2O, where oxen is N, N'-bis(2-aminoethyl) oxamide dianion, has been synthesized. It crystallizes in triclinic system, space group P1, with a=11.486 (2), b=11.706 (3), c=12.291 (3)Å, α=77.42 (2), β=67.59 (2), γ=77.96 (2)°, and z=2. The least-square refinements converged at R=0.047, with 3416 observed unique reflections. The complex has a pronounced three-dimensional character and can be viewed as the tetranuclear asymmetric repeating units through inversion and translation operations to extend a three-dimensional network. The structure of Cu4 asymmetric unit consists of two square planar and two square pyramidal Cu central atoms linked by both azide ligands in end-on and end-to-end bonding modes, and oxamidate bridge in trans conformation.
1993, 4(11): 1031-1032
Abstract:
The copper-cobalt based catalysts were effective for higher alcohol synthesis, the surface state of the catalysts and the nature of the active sites were investigated by using XPS and XAES spectra, and some strong interactions were also observed, in each of the three cases, (after calcination, after reduction, and during the syngas reaction).
The copper-cobalt based catalysts were effective for higher alcohol synthesis, the surface state of the catalysts and the nature of the active sites were investigated by using XPS and XAES spectra, and some strong interactions were also observed, in each of the three cases, (after calcination, after reduction, and during the syngas reaction).
1993, 4(11): 1033-1034
Abstract:
Mo2OS (μ-S) 2[S2CNC4H8]2, Mr=612.61, triclinic, P1, a=8.666 (2)Å, b=17.366 (6)Å, c=6.708 (1)Å, α=98.29 (2)°, β=97.27 (2)°, γ=79.36 (2)°, V=976.5 (5)Å3, Z=2, Dc=2.03g/cm3, MoKα (λ=0.71069 (?)), μ=19.75cm-1, F (000)=588, Final R=0.064, Rw=0.073 for 1517 unique intensity data (I>3σ(I)). The binuclear unit of[Mo2OS3] has a new asymmetrically terminal coordinated configuration with Mo-Mo distance of 2.807(3)Å.
Mo2OS (μ-S) 2[S2CNC4H8]2, Mr=612.61, triclinic, P1, a=8.666 (2)Å, b=17.366 (6)Å, c=6.708 (1)Å, α=98.29 (2)°, β=97.27 (2)°, γ=79.36 (2)°, V=976.5 (5)Å3, Z=2, Dc=2.03g/cm3, MoKα (λ=0.71069 (?)), μ=19.75cm-1, F (000)=588, Final R=0.064, Rw=0.073 for 1517 unique intensity data (I>3σ(I)). The binuclear unit of[Mo2OS3] has a new asymmetrically terminal coordinated configuration with Mo-Mo distance of 2.807(3)Å.
