The potential of di-(m-Formylphenol)-1,2-cyclohexandiimine as an environmentally friendly corrosion inhibitor for steel was investigated in 1 mol/L HCl using potentiodynamic polarization, electrochemical impedance spe...The potential of di-(m-Formylphenol)-1,2-cyclohexandiimine as an environmentally friendly corrosion inhibitor for steel was investigated in 1 mol/L HCl using potentiodynamic polarization, electrochemical impedance spectroscopy and chronoamperometry measurements. All electrochemical measurements suggest that this compound is an excellent corrosion inhibitor for mild steel and the inhibition efficiency increases with the increase in inhibitor concentration. The effect of temperature on the corrosion behavior of mild steel with the addition of the Schiff base was studied in the temperature range from 25 °C to 65 °C. It is found that the adsorption of this inhibitor follows the Langmuir adsorption isotherms. The value of activation energy and the thermodynamic parameters such as ΔHads, ΔSads, Kads and ΔGads were calculated by the corrosion currents at different temperatures using the adsorption isotherm. The morphology of mild steel surface in the absence and presence of inhibitor was examined by scanning electron microscopy(SEM) images.展开更多
Complexes of La （III）, Nd（III）, Gd（III）, Sm（III）, and Ce（IV） were synthesized with Schiff base [（3,5-di-tert-butyl-2-hy- droxybenzyl） amino] acetic acid （H3L）. The ligand and its complexes were synthesiz...Complexes of La （III）, Nd（III）, Gd（III）, Sm（III）, and Ce（IV） were synthesized with Schiff base [（3,5-di-tert-butyl-2-hy- droxybenzyl） amino] acetic acid （H3L）. The ligand and its complexes were synthesized and characterized based on the following analysis： elemental analyses, FAB-mass, molar conductance measurements, magnetic measurement, UV-visible, IR, and NMR spectral studies. The spectral data revealed that the ligand acted as a neutral tridentate coordinating to metal ion through ONO donor sequence. Thermal degradation studies of the ligand and its complexes showed that the previous lanthanide complexes were more thermally stable than the ligand itself. The Schiff base and its complexes were screened for their antibacterial （Escherichia coli, Staphylococcus aureus） and antifungal （Aspergillus flavus and Candida Albicans）.展开更多
Objective:To evaluate the anticancer activity of vanillin semicarbazone(VSC) against Ehrlich ascites carcinoma(EAC) cells in Swiss albino mice.Methods:The compound VSC at three doses(5, 7.5 and 10 mg/kg i.p.) was admi...Objective:To evaluate the anticancer activity of vanillin semicarbazone(VSC) against Ehrlich ascites carcinoma(EAC) cells in Swiss albino mice.Methods:The compound VSC at three doses(5, 7.5 and 10 mg/kg i.p.) was administered into the intraperitoneal cavity of the EAC inoculated mice to observe its efficiency by studying the cell growth inhibition, reduction of tumour weight,enhancement of survival time as well as the changes in depleted hematological parameters. Allsuch parameters were also studied with a known standard drug bleomycin at the dose of 0.3 mg/kg(i.p.).Results:Among the doses studied, 10 mg/kg(i.p.) was found to be quite comparable in potency to that of bleomycin at the dose of 0.3 mg/kg(i.p.). The host toxic effects of VSC was found to be negligible.Conclusions:It can be concluded that VSC can therefore be considered as potent anticancer agent.展开更多
The oxygenation constants of transition-metal complexes with benzoin Schiff bases were measured and these complexes were first employed as models for mimicking monooxygenase in catalytic epoxidation of styrene. The hi...The oxygenation constants of transition-metal complexes with benzoin Schiff bases were measured and these complexes were first employed as models for mimicking monooxygenase in catalytic epoxidation of styrene. The highest conversion and selectivity were up to 39.6% and 100% respectively at ambient temperature and pressure. The effects of structures of the bridge group R in the ligands on the dioxygen affinities and catalytic activities to epoxidize styrene were also investigated.展开更多
Novel 1,3-distal p-tert-butylcalix[4]arene Schiff bases were efficiently synthesized in three steps. At first p-tert-hutylcalix[4]arene was reacted with N-2-hydroxyethylphthalimide catalyzed by TPP/DEAD or alkylated w...Novel 1,3-distal p-tert-butylcalix[4]arene Schiff bases were efficiently synthesized in three steps. At first p-tert-hutylcalix[4]arene was reacted with N-2-hydroxyethylphthalimide catalyzed by TPP/DEAD or alkylated with ω-hatoalkylphthalimide in the system of K2CO3/KI/CH3COCH3 to give 1,3-distal diphthalimidoalkyl calixarenes, which were in turn hydrazinolyzed to give diaminoalkyl calixarenes. Then with the aid of the condensation of active calixarene amines with salicylaldehyde, 2-hydroxy-l-naphthaldehyde or pyridine-2-carboxaldehyde, a series of 1,3-distal calixarene Schiff bases was prepared in satisfied yields. The single crystal structures and complexing properties of these Schiff bases for transition metal ions were studied.展开更多
The corrosion inhibition of mild steel in 1 mol/L HC1 by N, N＇-bis （2-hydroxybenzaldehyde）- 1, 3-propandiimine （2-HBP） has been investigated by using potentiodynamic polarization, electrochemical impedance spectr...The corrosion inhibition of mild steel in 1 mol/L HC1 by N, N＇-bis （2-hydroxybenzaldehyde）- 1, 3-propandiimine （2-HBP） has been investigated by using potentiodynamic polarization, electrochemical impedance spectroscopy （EIS） and chronoamperometry measurements. The experimental results suggest that this compound is an excellent corrosion inhibitor for mild steel and the inhibition efficiency increases with the increase in inhibitor concentration. Polarization curves reveal that this organic compound is a mixed type inhibitor. The effect of temperature on the corrosion behavior of mild steel with the addition of the Schiff base was studied in the temperature range from 25 ℃ to 65℃. The experimentally obtained adsorption isotherms follow the Langmuir equation. Activation and thermodynamic adsorption parameters such as Ea, △H, △S,Kads and AG,ds were calculated by the corrosion currents at different temperatures and using the adsorption isotherm. The morphology of mild steel surface in the absence and presence of 2-HBP was examined by atomic force microscope （AFM） images.展开更多
The crystal structures of two potential tumor imaging agents and therapeutic agents -copper(Ⅱ) complexes with salicylidene-tyrosinato Schiff base and nitrogen-donor chelating Lewis base, [Cu(sal-tyr)(bipy)] 1 and [Cu...The crystal structures of two potential tumor imaging agents and therapeutic agents -copper(Ⅱ) complexes with salicylidene-tyrosinato Schiff base and nitrogen-donor chelating Lewis base, [Cu(sal-tyr)(bipy)] 1 and [Cu(sal-tyr)(phen)]2CH3OH 2 are presented. Our work is helpful to get deep understanding of novel 64Cu tumor imaging agents and therapeutic agents.展开更多
The authors have prepared suprameolecular systems of chiral Schiffbase ZnAZSB （Zn（II） complexes with azo-groups） or without ZnSB （azo-groups） and colloidal AuNP （gold nanoparticles） of 10, 40 and 80 nm diamete...The authors have prepared suprameolecular systems of chiral Schiffbase ZnAZSB （Zn（II） complexes with azo-groups） or without ZnSB （azo-groups） and colloidal AuNP （gold nanoparticles） of 10, 40 and 80 nm diameters. They exhibited gradual shifts of surface plasmon bands as well as fluorescence bands. The authors observed and discussed induced CD bands on gold nanoparticles from chiral ZnAZSB or ZnSB. Absence of cis-trans photoisomerization of ZnAZSB with AuNP also supported direct contact near the surface of AuNP. Quenching and splitting of fluorescence bands of ZnSB （λex = 550 nm and λem = 400 nm） depending on concentration of ZnSB and size of AuNP also suggested intermolecular （electric） interaction on the surface of AuNE Decrease of the intensity of the CD band around 380 nm resulted from reciprocal induced CD effect due to parallel arrangement of electric transition moments of ZnAZSB or ZnSB and surface of AuNP.展开更多
Various compounds of 4-aminoantipyrine Schiff bases(M1–M12) were synthesized via a condensation reaction of 4-aminoantipyrine with different benzaldehydes through a conventional method of refluxing the mixture for 3...Various compounds of 4-aminoantipyrine Schiff bases(M1–M12) were synthesized via a condensation reaction of 4-aminoantipyrine with different benzaldehydes through a conventional method of refluxing the mixture for 3–4 h. The synthesized Schiff bases were characterized by using elemental analyses, FT-IR, UV-Vis, Mass, 1 H and 13 C NMR spectroscopy. The antimicrobial activity of the synthesized Schiff bases was investigated against 12 bacterial strains(Mycobacterium smegmatis, Bacillus cereus, Bacillus subtilis, Enterococcus faecalis, Staphylococcus epidermidis, Klebsiella pneumonia, Escherichia coli, Enterobacter cloacae, Klebsiella oxytoca, Proteus vulgaris, Enterobacter aerogenes, and Pseudomonas aeruginosa), and antifungal activities were tested against seven fungal strains(Aspergillus flavus, Aspergillus carbonarious, Aspergillus parasiticus, Aspergillus fumigatus, Aspergillus niger, Fusarium verticillioides and Fusarium proliferatum). The antimicrobial activities of the synthesized compounds were compared with standard streptomycin and nalidixic acid. The results obtained from antibacterial assay indicated that M1–M12 inhibited potential growth of Proteus vulgaris with minimum inhibitory concentrations(MICs) ranging from 15.6–250 μg/mL compared with the standard nalidixic acid with an MIC of 500 μg/mL. Moreover, we could conclude that most of the tested compounds experienced mild to low activities at 15.6 μg/mL. Their activities could be attributed to their low concentration s. The antifungal analysis showed that the tested fungi were not sensitive to the prepared Schiff bases at the prepared concentration of 500 μg/mL. Therefore, we recommended further analysis on both cytotoxicity and minimum bactericidal concentration(MBC) to ascertain their potential effects against human cells.展开更多
A number of tetrazoles derivatives were prepared by series of steps, the first step includes react （4,5-dichloroimidazole） with （4-aminoacetophenone） to form 1-（4-（（4,5-dichloro-lH-imidazol-2yl）diazenyl）ethan...A number of tetrazoles derivatives were prepared by series of steps, the first step includes react （4,5-dichloroimidazole） with （4-aminoacetophenone） to form 1-（4-（（4,5-dichloro-lH-imidazol-2yl）diazenyl）ethanone （1）. The second step was （1） reaction with （Amines derivatives） to get Schiff bases （2-7）. The third step was reaction of Shciff base with sodiumazide to form tetrazoles derivatives （8-13）. then study the biological activity for all compounds to word two type of bacteria.展开更多
Electrochemically, laccase, a family of multi-copper oxidase, has specificity for performing not only one-electron oxidation of phenolic-related compounds but also four-electron reduction of oxygen, which is expected ...Electrochemically, laccase, a family of multi-copper oxidase, has specificity for performing not only one-electron oxidation of phenolic-related compounds but also four-electron reduction of oxygen, which is expected to be a cathode of biofuel ceils. We have prepared three amino-acid derivatives （for enhancing affinity to laccase） and one control （just for determining redox behavior of ligands and Cu（II/I）） copper（lI） complexes 0-3 having phenolic-related ligands involving anthraquinone moiety. Enhancing current density of electron transfer between the cathode （composed of electron conducting materials such as Nation and carbon nanotube） and laccase could be observed for all 1-3 acting as good mediators according to （spectro）electrochemical results.展开更多
Poly（p-arylene sulfide ketone/Schiffbase） copolymers （PASK/SB） were prepared by solution polycondensation of 4,4＇-diflurobenzophenone （DFBP） and N-phenyl（4,4＇-diflurodiphenyl） ketimine （DFBI） with sodium s...Poly（p-arylene sulfide ketone/Schiffbase） copolymers （PASK/SB） were prepared by solution polycondensation of 4,4＇-diflurobenzophenone （DFBP） and N-phenyl（4,4＇-diflurodiphenyl） ketimine （DFBI） with sodium sulfide in the presence of sodium hydroxide under normal pressure. Elemental analyses, FT-IR, NMR, DSC, TGA and XRD were used to characterize the resultant copolymers. It was found that the copolymers had good thermal properties with glass transition temperature （Tg） of 155.0-172.0℃, melting temperature （Tm） of 298-344℃, 5% weight loss temperatures （Td） of 471.0-501.5℃. These copolymers were almost amorphous with the content of DFBI beyond 30%. The polymer with 100% DFBI had excellent solubility, and it could dissolve in some solvents such as tetrahydrofuran （THF） and N-methyl-2- pyrrolidone （NMP）. The processability of polymers was improved. Meantime the viscosity of PASK made from hydrolysis of PASK/SB （H-PASK/SB） was greatly improved from 0.135 dL/g to 0.605 dL/g.展开更多
A new schiff base complex derived from furfural-DL-α-alanine and Dy(NO_3)·6H_2O was synthesized. It was characterized by elemental analysis, infrared spectra, ultraviolet spectra, molar conductivity measurements...A new schiff base complex derived from furfural-DL-α-alanine and Dy(NO_3)·6H_2O was synthesized. It was characterized by elemental analysis, infrared spectra, ultraviolet spectra, molar conductivity measurements and thermogravimetric analysis. The stoichiometry was deduced to be [Dy(C_8H_8NO_3)(H_2O)(NO_3)](H_2O)(NO_3). Its thermal decomposition reaction kinetics was studied by thermogravimetry.展开更多
First to third-generation calix[4] resorcinarene core dendrimers, compounds 4a, 4b, 7a, 7b, 10a and 10b, were prepared via the divergent method in seven steps with the corresponding tetraphenyl- and tetra （hydroxyphe...First to third-generation calix[4] resorcinarene core dendrimers, compounds 4a, 4b, 7a, 7b, 10a and 10b, were prepared via the divergent method in seven steps with the corresponding tetraphenyl- and tetra （hydroxyphenyl） calix[4] resorcinarenes （compounds 1a, 1b） as the starting material. The repeat units of the polyamidoamines of these dendrimers were obtained by the ammonolysis of ethyl calixarylacetates 2a and 2b with 1,3-diaminopropane, that is, amide derivatives with terminal amino groups, which in turn reacted with ethyl acrylate to give a higher generation of ester derivatives. The structures of these dendrimers were characterized by IR, ^1H and ^13C NMR spoctrometries. The crystal structure of compound 2b with 12 ethoxycarbonylmethoxy groups was determined by X-ray analysis.展开更多
Four kinds of bis(N-alkylsalicylaldiminato) zinc(II) complexes were synthesized, and their molecular structures were determined by FT-IR and elemental analysis. Their photoluminescence properties were determined, whic...Four kinds of bis(N-alkylsalicylaldiminato) zinc(II) complexes were synthesized, and their molecular structures were determined by FT-IR and elemental analysis. Their photoluminescence properties were determined, which indicated that they could emit strong fluorescence varying from blue to yellow to reddish orange depending on their different molecular structures. They had good thermostability, solubility and film forming capability, and can be used as organic lectroluminescent materials. These new complexes may afford the feasibility to realize full-color display with materials based on similar molecular structures.展开更多
Using Schiff base as a phase transfer catalyst, ethoxycarbonyl isothiocyanate was synthesized by reacting ethyl chloroformate with sodium thiocyanate. In order to get the best synthetic technology, an orthogonal test ...Using Schiff base as a phase transfer catalyst, ethoxycarbonyl isothiocyanate was synthesized by reacting ethyl chloroformate with sodium thiocyanate. In order to get the best synthetic technology, an orthogonal test （L9（34）） was applied. The results show that reaction temperature, reaction time, content of catalyst and molar ratio of sodium thiocyanate to ethyl chloroformate are the main factors influencing the yield. The four factors chosen for the present investigation are based on the results of a single-factor test. The optimum synthetic technology is determined as follows： reaction temperature 35 ℃, reaction time 3 h, the content of catalyst （molar fraction based on ethyl chloroformate） 1.5% and molar ratio of sodium thiocyanate to ethyl chloroformate 1.1. Under the optimized synthetic technology, the experimental yield reaches 96.8%.展开更多
Two Schiff base complexes [Cu（L）2] （1） and [Zn（L）2]·3H2O（2） of （E）-4-fluoro-2-（（3-morpholino propylimino）methyl）phenol （HL） have been synthesized and characterized by elemental analysis and single...Two Schiff base complexes [Cu（L）2] （1） and [Zn（L）2]·3H2O（2） of （E）-4-fluoro-2-（（3-morpholino propylimino）methyl）phenol （HL） have been synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. Crystal data for 1： triclinic, space group Pī with a=4.8000（10）, b=11.109（2）, c=13.921（3）,α=66.55（3）,β=80.35（3）,γ=81.09（3）°, V=668.2（2）3 , Z=1, Dc=1.477g/cm 3 , F（000）=311, and the final R=0.0744 and wR=0.1601 for 2301 observed reflections with I 〉 2σ（I）. And those for 2： monoclinic, space group P21 /c with a=14.789（3）, b=11.713（2）, c=18.846（4）,β=107.85（3）°, V=3107.4（11）3 , Z=4, D c=1.389 g/cm 3 , F（000）=1368, and the final R=0.0749 and wR=0.1348 for 5423 observed reflections with I 〉 2σ（I）. Both 1 and 2 are four-coordinated complexes, with a square-planar geometry of copper（Ⅱ） in 1 and a slightly distorted tetrahedral geometry of zinc（Ⅱ） in 2. An asymmetric unit consists of only one half of a Cu ion and one L ligand in 1, while an asymmetric unit is composed of one Zn ion, two L ligands and three water molecules in 2. Non-classical C-H···O and C-H F hydrogen bonds play important roles in the formation of a 1D chain of 1, but O-H O and O-H N hydrogen bonds play dominant roles in the self-assembly of a 3D network of 2. The antibacterial activities of 1 and 2 against B. subtilis, S. aureus, S. faecalis, P. aeruginosa, E. coli and E. cloacae have been evaluated by MTT method.展开更多
An efficient enantioselective Michael addition of ethyl-2-cyanoacetate and diethyl malonate to α,β-unsaturated ketones catalyzed by a simple chiral Schiff base, and products were obtained in good yields at room temp...An efficient enantioselective Michael addition of ethyl-2-cyanoacetate and diethyl malonate to α,β-unsaturated ketones catalyzed by a simple chiral Schiff base, and products were obtained in good yields at room temperature.展开更多
文摘The potential of di-(m-Formylphenol)-1,2-cyclohexandiimine as an environmentally friendly corrosion inhibitor for steel was investigated in 1 mol/L HCl using potentiodynamic polarization, electrochemical impedance spectroscopy and chronoamperometry measurements. All electrochemical measurements suggest that this compound is an excellent corrosion inhibitor for mild steel and the inhibition efficiency increases with the increase in inhibitor concentration. The effect of temperature on the corrosion behavior of mild steel with the addition of the Schiff base was studied in the temperature range from 25 °C to 65 °C. It is found that the adsorption of this inhibitor follows the Langmuir adsorption isotherms. The value of activation energy and the thermodynamic parameters such as ΔHads, ΔSads, Kads and ΔGads were calculated by the corrosion currents at different temperatures using the adsorption isotherm. The morphology of mild steel surface in the absence and presence of inhibitor was examined by scanning electron microscopy(SEM) images.
文摘Complexes of La （III）, Nd（III）, Gd（III）, Sm（III）, and Ce（IV） were synthesized with Schiff base [（3,5-di-tert-butyl-2-hy- droxybenzyl） amino] acetic acid （H3L）. The ligand and its complexes were synthesized and characterized based on the following analysis： elemental analyses, FAB-mass, molar conductance measurements, magnetic measurement, UV-visible, IR, and NMR spectral studies. The spectral data revealed that the ligand acted as a neutral tridentate coordinating to metal ion through ONO donor sequence. Thermal degradation studies of the ligand and its complexes showed that the previous lanthanide complexes were more thermally stable than the ligand itself. The Schiff base and its complexes were screened for their antibacterial （Escherichia coli, Staphylococcus aureus） and antifungal （Aspergillus flavus and Candida Albicans）.
基金financially supported by University Grants Commission of Bangladesh[grant No.6(76)/UGC/BK/Chemistry(9)/2007-2008/3268]
文摘Objective:To evaluate the anticancer activity of vanillin semicarbazone(VSC) against Ehrlich ascites carcinoma(EAC) cells in Swiss albino mice.Methods:The compound VSC at three doses(5, 7.5 and 10 mg/kg i.p.) was administered into the intraperitoneal cavity of the EAC inoculated mice to observe its efficiency by studying the cell growth inhibition, reduction of tumour weight,enhancement of survival time as well as the changes in depleted hematological parameters. Allsuch parameters were also studied with a known standard drug bleomycin at the dose of 0.3 mg/kg(i.p.).Results:Among the doses studied, 10 mg/kg(i.p.) was found to be quite comparable in potency to that of bleomycin at the dose of 0.3 mg/kg(i.p.). The host toxic effects of VSC was found to be negligible.Conclusions:It can be concluded that VSC can therefore be considered as potent anticancer agent.
文摘The oxygenation constants of transition-metal complexes with benzoin Schiff bases were measured and these complexes were first employed as models for mimicking monooxygenase in catalytic epoxidation of styrene. The highest conversion and selectivity were up to 39.6% and 100% respectively at ambient temperature and pressure. The effects of structures of the bridge group R in the ligands on the dioxygen affinities and catalytic activities to epoxidize styrene were also investigated.
基金Supported by the National Natural Science Foundation of China(No.20672091)
文摘Novel 1,3-distal p-tert-butylcalix[4]arene Schiff bases were efficiently synthesized in three steps. At first p-tert-hutylcalix[4]arene was reacted with N-2-hydroxyethylphthalimide catalyzed by TPP/DEAD or alkylated with ω-hatoalkylphthalimide in the system of K2CO3/KI/CH3COCH3 to give 1,3-distal diphthalimidoalkyl calixarenes, which were in turn hydrazinolyzed to give diaminoalkyl calixarenes. Then with the aid of the condensation of active calixarene amines with salicylaldehyde, 2-hydroxy-l-naphthaldehyde or pyridine-2-carboxaldehyde, a series of 1,3-distal calixarene Schiff bases was prepared in satisfied yields. The single crystal structures and complexing properties of these Schiff bases for transition metal ions were studied.
文摘The corrosion inhibition of mild steel in 1 mol/L HC1 by N, N＇-bis （2-hydroxybenzaldehyde）- 1, 3-propandiimine （2-HBP） has been investigated by using potentiodynamic polarization, electrochemical impedance spectroscopy （EIS） and chronoamperometry measurements. The experimental results suggest that this compound is an excellent corrosion inhibitor for mild steel and the inhibition efficiency increases with the increase in inhibitor concentration. Polarization curves reveal that this organic compound is a mixed type inhibitor. The effect of temperature on the corrosion behavior of mild steel with the addition of the Schiff base was studied in the temperature range from 25 ℃ to 65℃. The experimentally obtained adsorption isotherms follow the Langmuir equation. Activation and thermodynamic adsorption parameters such as Ea, △H, △S,Kads and AG,ds were calculated by the corrosion currents at different temperatures and using the adsorption isotherm. The morphology of mild steel surface in the absence and presence of 2-HBP was examined by atomic force microscope （AFM） images.
文摘The crystal structures of two potential tumor imaging agents and therapeutic agents -copper(Ⅱ) complexes with salicylidene-tyrosinato Schiff base and nitrogen-donor chelating Lewis base, [Cu(sal-tyr)(bipy)] 1 and [Cu(sal-tyr)(phen)]2CH3OH 2 are presented. Our work is helpful to get deep understanding of novel 64Cu tumor imaging agents and therapeutic agents.
文摘The authors have prepared suprameolecular systems of chiral Schiffbase ZnAZSB （Zn（II） complexes with azo-groups） or without ZnSB （azo-groups） and colloidal AuNP （gold nanoparticles） of 10, 40 and 80 nm diameters. They exhibited gradual shifts of surface plasmon bands as well as fluorescence bands. The authors observed and discussed induced CD bands on gold nanoparticles from chiral ZnAZSB or ZnSB. Absence of cis-trans photoisomerization of ZnAZSB with AuNP also supported direct contact near the surface of AuNP. Quenching and splitting of fluorescence bands of ZnSB （λex = 550 nm and λem = 400 nm） depending on concentration of ZnSB and size of AuNP also suggested intermolecular （electric） interaction on the surface of AuNE Decrease of the intensity of the CD band around 380 nm resulted from reciprocal induced CD effect due to parallel arrangement of electric transition moments of ZnAZSB or ZnSB and surface of AuNP.
基金supported by the Faculty of Science,Department of Applied Chemistrythe University of Johannesburg for providing enabling environment to perform this workthe National Research Foundation(NRF)for the provision of running cost of this work
文摘Various compounds of 4-aminoantipyrine Schiff bases(M1–M12) were synthesized via a condensation reaction of 4-aminoantipyrine with different benzaldehydes through a conventional method of refluxing the mixture for 3–4 h. The synthesized Schiff bases were characterized by using elemental analyses, FT-IR, UV-Vis, Mass, 1 H and 13 C NMR spectroscopy. The antimicrobial activity of the synthesized Schiff bases was investigated against 12 bacterial strains(Mycobacterium smegmatis, Bacillus cereus, Bacillus subtilis, Enterococcus faecalis, Staphylococcus epidermidis, Klebsiella pneumonia, Escherichia coli, Enterobacter cloacae, Klebsiella oxytoca, Proteus vulgaris, Enterobacter aerogenes, and Pseudomonas aeruginosa), and antifungal activities were tested against seven fungal strains(Aspergillus flavus, Aspergillus carbonarious, Aspergillus parasiticus, Aspergillus fumigatus, Aspergillus niger, Fusarium verticillioides and Fusarium proliferatum). The antimicrobial activities of the synthesized compounds were compared with standard streptomycin and nalidixic acid. The results obtained from antibacterial assay indicated that M1–M12 inhibited potential growth of Proteus vulgaris with minimum inhibitory concentrations(MICs) ranging from 15.6–250 μg/mL compared with the standard nalidixic acid with an MIC of 500 μg/mL. Moreover, we could conclude that most of the tested compounds experienced mild to low activities at 15.6 μg/mL. Their activities could be attributed to their low concentration s. The antifungal analysis showed that the tested fungi were not sensitive to the prepared Schiff bases at the prepared concentration of 500 μg/mL. Therefore, we recommended further analysis on both cytotoxicity and minimum bactericidal concentration(MBC) to ascertain their potential effects against human cells.
文摘A number of tetrazoles derivatives were prepared by series of steps, the first step includes react （4,5-dichloroimidazole） with （4-aminoacetophenone） to form 1-（4-（（4,5-dichloro-lH-imidazol-2yl）diazenyl）ethanone （1）. The second step was （1） reaction with （Amines derivatives） to get Schiff bases （2-7）. The third step was reaction of Shciff base with sodiumazide to form tetrazoles derivatives （8-13）. then study the biological activity for all compounds to word two type of bacteria.
文摘Electrochemically, laccase, a family of multi-copper oxidase, has specificity for performing not only one-electron oxidation of phenolic-related compounds but also four-electron reduction of oxygen, which is expected to be a cathode of biofuel ceils. We have prepared three amino-acid derivatives （for enhancing affinity to laccase） and one control （just for determining redox behavior of ligands and Cu（II/I）） copper（lI） complexes 0-3 having phenolic-related ligands involving anthraquinone moiety. Enhancing current density of electron transfer between the cathode （composed of electron conducting materials such as Nation and carbon nanotube） and laccase could be observed for all 1-3 acting as good mediators according to （spectro）electrochemical results.
基金financially supported by the National High Technology Foundation of China(No.2007AA03Z561).
文摘Poly（p-arylene sulfide ketone/Schiffbase） copolymers （PASK/SB） were prepared by solution polycondensation of 4,4＇-diflurobenzophenone （DFBP） and N-phenyl（4,4＇-diflurodiphenyl） ketimine （DFBI） with sodium sulfide in the presence of sodium hydroxide under normal pressure. Elemental analyses, FT-IR, NMR, DSC, TGA and XRD were used to characterize the resultant copolymers. It was found that the copolymers had good thermal properties with glass transition temperature （Tg） of 155.0-172.0℃, melting temperature （Tm） of 298-344℃, 5% weight loss temperatures （Td） of 471.0-501.5℃. These copolymers were almost amorphous with the content of DFBI beyond 30%. The polymer with 100% DFBI had excellent solubility, and it could dissolve in some solvents such as tetrahydrofuran （THF） and N-methyl-2- pyrrolidone （NMP）. The processability of polymers was improved. Meantime the viscosity of PASK made from hydrolysis of PASK/SB （H-PASK/SB） was greatly improved from 0.135 dL/g to 0.605 dL/g.
文摘A new schiff base complex derived from furfural-DL-α-alanine and Dy(NO_3)·6H_2O was synthesized. It was characterized by elemental analysis, infrared spectra, ultraviolet spectra, molar conductivity measurements and thermogravimetric analysis. The stoichiometry was deduced to be [Dy(C_8H_8NO_3)(H_2O)(NO_3)](H_2O)(NO_3). Its thermal decomposition reaction kinetics was studied by thermogravimetry.
文摘First to third-generation calix[4] resorcinarene core dendrimers, compounds 4a, 4b, 7a, 7b, 10a and 10b, were prepared via the divergent method in seven steps with the corresponding tetraphenyl- and tetra （hydroxyphenyl） calix[4] resorcinarenes （compounds 1a, 1b） as the starting material. The repeat units of the polyamidoamines of these dendrimers were obtained by the ammonolysis of ethyl calixarylacetates 2a and 2b with 1,3-diaminopropane, that is, amide derivatives with terminal amino groups, which in turn reacted with ethyl acrylate to give a higher generation of ester derivatives. The structures of these dendrimers were characterized by IR, ^1H and ^13C NMR spoctrometries. The crystal structure of compound 2b with 12 ethoxycarbonylmethoxy groups was determined by X-ray analysis.
文摘Four kinds of bis(N-alkylsalicylaldiminato) zinc(II) complexes were synthesized, and their molecular structures were determined by FT-IR and elemental analysis. Their photoluminescence properties were determined, which indicated that they could emit strong fluorescence varying from blue to yellow to reddish orange depending on their different molecular structures. They had good thermostability, solubility and film forming capability, and can be used as organic lectroluminescent materials. These new complexes may afford the feasibility to realize full-color display with materials based on similar molecular structures.
基金Project(2007AA06Z122) supported by the National High Technology Research and Development Program of ChinaProject(20110491267) supported by the Postdoctoral Science Foundation of ChinaProject(74341015502) supported by Postdoctoral Fund of Central South University,China
文摘Using Schiff base as a phase transfer catalyst, ethoxycarbonyl isothiocyanate was synthesized by reacting ethyl chloroformate with sodium thiocyanate. In order to get the best synthetic technology, an orthogonal test （L9（34）） was applied. The results show that reaction temperature, reaction time, content of catalyst and molar ratio of sodium thiocyanate to ethyl chloroformate are the main factors influencing the yield. The four factors chosen for the present investigation are based on the results of a single-factor test. The optimum synthetic technology is determined as follows： reaction temperature 35 ℃, reaction time 3 h, the content of catalyst （molar fraction based on ethyl chloroformate） 1.5% and molar ratio of sodium thiocyanate to ethyl chloroformate 1.1. Under the optimized synthetic technology, the experimental yield reaches 96.8%.
基金supported by the China Postdoctoral Science Foundation (No.20110491380)the Fundamental Research Funds for the Central Universities (No.ZYGX2009J085)
文摘Two Schiff base complexes [Cu（L）2] （1） and [Zn（L）2]·3H2O（2） of （E）-4-fluoro-2-（（3-morpholino propylimino）methyl）phenol （HL） have been synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. Crystal data for 1： triclinic, space group Pī with a=4.8000（10）, b=11.109（2）, c=13.921（3）,α=66.55（3）,β=80.35（3）,γ=81.09（3）°, V=668.2（2）3 , Z=1, Dc=1.477g/cm 3 , F（000）=311, and the final R=0.0744 and wR=0.1601 for 2301 observed reflections with I 〉 2σ（I）. And those for 2： monoclinic, space group P21 /c with a=14.789（3）, b=11.713（2）, c=18.846（4）,β=107.85（3）°, V=3107.4（11）3 , Z=4, D c=1.389 g/cm 3 , F（000）=1368, and the final R=0.0749 and wR=0.1348 for 5423 observed reflections with I 〉 2σ（I）. Both 1 and 2 are four-coordinated complexes, with a square-planar geometry of copper（Ⅱ） in 1 and a slightly distorted tetrahedral geometry of zinc（Ⅱ） in 2. An asymmetric unit consists of only one half of a Cu ion and one L ligand in 1, while an asymmetric unit is composed of one Zn ion, two L ligands and three water molecules in 2. Non-classical C-H···O and C-H F hydrogen bonds play important roles in the formation of a 1D chain of 1, but O-H O and O-H N hydrogen bonds play dominant roles in the self-assembly of a 3D network of 2. The antibacterial activities of 1 and 2 against B. subtilis, S. aureus, S. faecalis, P. aeruginosa, E. coli and E. cloacae have been evaluated by MTT method.
基金We appreciate the National Natural Science Foundation of China （No. 20962018, 20862015, 20762009 and 20562011） for supporting this research.
文摘An efficient enantioselective Michael addition of ethyl-2-cyanoacetate and diethyl malonate to α,β-unsaturated ketones catalyzed by a simple chiral Schiff base, and products were obtained in good yields at room temperature.
