The synthetic process for 2,2-dimethyl-5-nitro-5-nitroso-1,3-dioxane(DMNNDO) was improved by using tri(hydroxymethyl)nitromethane and acetone as starting materials through a "one-pot" method combined with alkali...The synthetic process for 2,2-dimethyl-5-nitro-5-nitroso-1,3-dioxane(DMNNDO) was improved by using tri(hydroxymethyl)nitromethane and acetone as starting materials through a "one-pot" method combined with alkaline hydrolysis and nitrosation reactions. The yield of DMNNDO was increased from 37% to 45%. The structure of DMNNDO was characterized by IR,^1H NMR,^13 C NMR,and elemental analysis. Also the thermal decomposition of DMNNDO was studied by using DSC and TG-DTG to find that there are primarily two exothermic decomposition processes between 90 and 300 oC. The crystal structure of DMNNDO was studied by X-ray single-crystal diffraction for the first time. The molecular structure exists as a dimeric form due to the presence of nitroso group. The crystal belongs to monoclinic system,space group C2/c with a = 14.515(3),b = 9.955(2),c = 11.897(2) °,β = 98.500(3)°,V = 1.6998(2) nm^3,Z = 8,D_c = 1.486 g×cm^-3,μ = 0.128 mm^-1,F(000) = 800,S = 1.055,R = 0.0358 and wR = 0.0917. In particular,DMNNDO could be easily hydrolyzed in hydrous systems and the hydrolysis mechanism in CDCl_3 was revealed by means of NMR monitoring.展开更多
Kinetic and conductivity of new Schiff bases compounds such ((12Z)N-(5Z)-1-bromo-5-(phenylimino)-1H- pyrrol-2(5 H)-ylidene)benzenamine {ArN(CNBrCCHCH)NAr} (Ar = C6H5) incorporating the chelating diamino ...Kinetic and conductivity of new Schiff bases compounds such ((12Z)N-(5Z)-1-bromo-5-(phenylimino)-1H- pyrrol-2(5 H)-ylidene)benzenamine {ArN(CNBrCCHCH)NAr} (Ar = C6H5) incorporating the chelating diamino has been studied in this paper and was found a second order of this reaction. Electronic Properties using hyperchem program study has been improved for this compound such angel and bond distance, and then this compound was defining as electric conductivity and did prove to be useful for conduclively compound.展开更多
Raspberry ketone {RK, 4-(4-hydroxyphenyl)butan-2-one} is a natural compound contained in raspberry, and is added to cosmetics for skin whitening. It is very important to measure the RK level in cosmetics for quality a...Raspberry ketone {RK, 4-(4-hydroxyphenyl)butan-2-one} is a natural compound contained in raspberry, and is added to cosmetics for skin whitening. It is very important to measure the RK level in cosmetics for quality assessment, since RK structurally resembles 4-(4-hydroxyphenyl)-2-butanol, which causes leukoderma on consumers’ skin. Here, we present a simple HPLC-fluorescence method for determination of RK in a fragrance mist by pre-column derivatization with 4-hydrazino-7-nitro-2,1,3-benzoxadiazole hydrazine (NBD-H), which reacts with the carbonyl group of RK. The NBD-RK derivative was eluted from a reversed-phase ODS column, and detected with excitation at 470 nm and emission at 550 nm. The retention time of NBD-RK derivative obtained by reaction with NBD-H at 80°C for 20 min was 10.3 min. The standard curve was linear in the range of 0.2 to 10 μg/mL, with a correlation coefficient (r<sup>2</sup>) value of 0.9980. The lower limit of detection was 0.018 μg/mL (absolute amount of 1.8 pmol). The coefficients of variation were less than 8.1%. The content of RK in fragrance mist (1.00 mL) was 1.18 ± 0.07 mg (range: 1.12 to 1.28 mg, n = 5). Recovery tests were satisfactory (83.9% ± 3.9%;range: 79.6 to 88.8%, n = 5).展开更多
The title compound has been synthesized and characterized crystallographicaUy. It is a co-crystal consisting of two different neutral zinc(H) complexes with Hbpbm (Hbpbm = 4- bromo-2-(benzimidazol-2-yl)phenol) a...The title compound has been synthesized and characterized crystallographicaUy. It is a co-crystal consisting of two different neutral zinc(H) complexes with Hbpbm (Hbpbm = 4- bromo-2-(benzimidazol-2-yl)phenol) and Hnpbm (Hnpbm = 2-(1-butylbenzimidazol-2-yl)phenol). One is a monomeric mixed-ligand complex of [Zn(bpbm)(npbm)] 1 and the other a dimer of [Zn2(npbm)4] 2 with their ratio of 2:1. Thus the overall formula for the title compound is 21.2. Adjacent 1 and 2 are connected to each other by intermolecular hydrogen bonding interactions in the lattice. The crystal data: monoclinic, space group P21/c, a = 15.0141(12), b = 20.9941(17), c = 18.4686(15) A, β = 97.445(2)°, V = 5772.4(8) A^3, Mr= 2429.68, Z = 2, Dc = 1.398 g/cm^3,μ = 1.579 -1 mm , F(000) = 2504, R = 0.0637 and wR = 0.1771 for 6464 observed reflections (I 〉 2σ(I)). The geometrical structure for 1 has also been theoretically optimized and compared with the experimental one.展开更多
Two new coordination polymers,{[Co(O2N-Hbtb)(phen)(H2O)3]·2H2O}n 1 and {[Cu3(O2N-btb)2(bipy)2(H2O)4]·4H2O}n 2(O2N-H3btb=5-nitro-1,2,3-benzenetricarboxylic acid,phen=1,10-phenanthroline,bipy=2,2...Two new coordination polymers,{[Co(O2N-Hbtb)(phen)(H2O)3]·2H2O}n 1 and {[Cu3(O2N-btb)2(bipy)2(H2O)4]·4H2O}n 2(O2N-H3btb=5-nitro-1,2,3-benzenetricarboxylic acid,phen=1,10-phenanthroline,bipy=2,2'-bipyridine),were prepared through hydrothermal reactions of Co(Ⅱ) or Cu(Ⅱ) salt with O2N-H3btb in the presence of different auxiliary N-donor ligands.Their crystal structures were determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis and IR spectroscopy.In the two complexes,O2N-H3btb ligand acts as monodentate and bis-monodentate modes,respectively.Complex 1 displays a two-dimensional layered structure through the inter-and intramolecular hydrogen bonding interactions while complex 2 has an O2N-btb bridged one-dimensional chain which is extended into a three-dimensional network by hydrogen bonding interactions.The magnetic properties of complex 2 are investigated over the temperature range of 2~300 K and ferromagnetic interactions are observed.展开更多
Due to acidic solutions aggressiveness, corrosion inhibitors use is considered to be one the most practical methods to delay metals dissolution in the said solutions. In this study benzimidazolyl derivative namely 2-c...Due to acidic solutions aggressiveness, corrosion inhibitors use is considered to be one the most practical methods to delay metals dissolution in the said solutions. In this study benzimidazolyl derivative namely 2-cyanochalcones 2-(5-nitro-1,3-dihydrobenzimidazol-2-ylidene)-3-oxo-3-(2-oxo-2H-chromen-3-yl) propanenitrile which was synthesized was then applied as a corrosion inhibitor for copper in 1 M HNO<sub>3</sub> solution. The inhibition action of this molecule was evaluated by gravimetric and density functional theory (DFT) methods. It was found experimentally that this compound has a better inhibition performance and its adsorption on copper surface follows Langmuir adsorption isotherm. This adsorption evolves with temperature and inhibitor concentration, it is endothermic and occurs spontaneously with an increase in disorder. Corrosion kinetic parameters analysis supported by Adejo-Ekwenchi model revealed the existence of both physisorption and chemisorption. DFT calculations related that compound adsorption on copper surface is due to its electron donating and accepting capacity. The reactive regions specifying the electrophilic and nucleophilic attack sites were analyzed using Fukui and dual descriptor functions. Experimental results obtained were compared with the theoretical findings.展开更多
The title compound 4-bromo-5-ethoxy-3-methyl-5-(naphthalen-l-yl)-l-tosyl-lH- pyrrol-2(5H)-one 1 (C24H22BrNO4S, Mr = 500.40) has been synthesized and its crystal structure was determined by single-crystal X-ray d...The title compound 4-bromo-5-ethoxy-3-methyl-5-(naphthalen-l-yl)-l-tosyl-lH- pyrrol-2(5H)-one 1 (C24H22BrNO4S, Mr = 500.40) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/n with a = 8.8562(15), b = 18.118(3), c = 14.055(2)A, β = 99.855(3)^o, V= 2221.9(6)A3, Z = 4, Dc = 1.496 g/cm^3,μ= 1.975 mm^-1, 2 = 0.71073A, F(000) = 1024, R = 0.0607 and wR = 0.1371.展开更多
The title compound N1-(2-(4-bromo-2-nitrophenoxy)-2-dimethyl acyloxymethyl)-5-fluorouracil(C15H13BrFN3O7, Mr = 446.19) was synthesized and structurally characterized by ^1H-NMR, -(13)C-NMR, ESI-MS and single-c...The title compound N1-(2-(4-bromo-2-nitrophenoxy)-2-dimethyl acyloxymethyl)-5-fluorouracil(C15H13BrFN3O7, Mr = 446.19) was synthesized and structurally characterized by ^1H-NMR, -(13)C-NMR, ESI-MS and single-crystal X-ray diffraction. The compound crystallizes in triclinic, space group P1, with a = 8.3325(6), b = 10.1808(13), c = 11.8194(16) A, α = 73.194(12), β= 72.351(9), γ = 89.509(8)o, V = 911.2(2) A^3, Z = 2, T = 300.79(10) K, μ(Cu Kα) = 3.578 mm^-1, Dc = 1.626 g/cm3, F(000) = 448.0, GOF = 1.060, 5723 reflections measured(8.232≤2θ≤139.592°), 3339 unique(Rint = 0.0184, Rsigma = 0.0254) which were used in all calculations. The final R = 0.0517(I 〉 2s(I)) and wR = 0.1494(all data). Hydrogen bonds and π-π interactions together stabilize the structure of the molecule. The preliminary biological test shows that the title compound has good antitumor activity against A549 in vitro and lower toxicity to normal cells.展开更多
This paper introduces the synthesis of a new color reagent 1-(6-nitro-2-benzothiazolyl)3-(4-nitrophenyl)-triazene (NBTNPT) and the color reaction of NBTNPT with Cd (II) has been studied. In the presence of Triton X-10...This paper introduces the synthesis of a new color reagent 1-(6-nitro-2-benzothiazolyl)3-(4-nitrophenyl)-triazene (NBTNPT) and the color reaction of NBTNPT with Cd (II) has been studied. In the presence of Triton X-100, the reagent with Cd (II) forms an orange-yellow complex (1:1) at pH=11.5-12.3, the molar absorptivity is 2.81x10(5)L . mol(-1)m(-1) by dual-wavelength spectrophotometry, Beers law is obeyed in the range of 0-280 mu g/L for Cd (II).展开更多
The title compound Ph3P=C(H)C(O)PhNO2 (L) has been prepared by the addition of triphenylphosphine in acetone as solvent to 2-bromo-1-(3,nitrophenyl)ethanone followed by the addition of alkaline solution of sod...The title compound Ph3P=C(H)C(O)PhNO2 (L) has been prepared by the addition of triphenylphosphine in acetone as solvent to 2-bromo-1-(3,nitrophenyl)ethanone followed by the addition of alkaline solution of sodium hydroxide. The yellow crystals of the title ylide were grown in methanol/chloroform solution by drop method without stirring at room temperature. The solid state structure of ylide has been established by X-ray crystallography analysis. In the molecule of the title compound, the geometry around the P atom is nearly tetrahedral and the O atom is in synperiplanar orientation to the P atom. The nitrophenyl ring is twisted with respect to the plane of the carbonyl group through an angle of 36.6(1)°. The crystal (C26H20NO3P, Mr = 425.40) belongs to the monoclinic system, space group P21/n with a = 10.889(3), b = 14.467(3), e = 13.872(4)A, β = 103.08(3)°, V = 2128.6(10) A3, Z= 4, T= 100(2) K, R = 0.059 and wR = 0.163 for 3984 observed reflections with I〉 2σ(I).展开更多
The thermal decomposition of 3-nitro-1,2,4-triazol-5-one magnesium complex and its kinetics were studied under the non-isothermal condition by DSC and TG/DTG methods. The kinetic parameters were obtained from analysis...The thermal decomposition of 3-nitro-1,2,4-triazol-5-one magnesium complex and its kinetics were studied under the non-isothermal condition by DSC and TG/DTG methods. The kinetic parameters were obtained from analysis of the DSC and TG/DTG curves by the Kissinger method,the Ozawa method,the differential method and the integral method. The most probable mechanism functions for the thermal decomposition of the first stage,the second stage and the third stage were suggested by comparing the kinetic parameters. The entropy of activation (ΔS ≠),enthalpy of activation (ΔH ≠) and free energy of activation (ΔG ≠) at Tpdo are -66.74 J·mol -1 ·K -1 ,119.2 kJ·mol -1 and 152.44 kJ·mol -1 ,respectively.展开更多
This article reported the distribution of DNase-1 sensitive regions in genomes of three Burkitt's lymphoma cell lines, P3HR-1, Raji and Ramos cell lines using a new method of in situ nick translation of chromosome...This article reported the distribution of DNase-1 sensitive regions in genomes of three Burkitt's lymphoma cell lines, P3HR-1, Raji and Ramos cell lines using a new method of in situ nick translation of chromosomes substituted completely by BrdU. The results showed that the Blym locus on chromosomes In three cell lines and the c-myc locus on chromosomes in P3HR-1 were the DNase-1 sensitive regions and found that the rearrangemental sites of chromosomes present in three Burkltt' s lymphoma cell lines were sensitive to DNase-1 digestion, Indicating that c-myc, bcl-1 genes located at the rearrangemental sites and the Blym gene in Burkltt' s lymphoma are the active genes having the capability of expression.展开更多
Preconcentration/separation of Co(II), Fe(III), Pb(II), Cr(IIl), Cu(II) and Cd(II) ions using bis(5-bromo- 2-hydroxy-benzaldehyde)-2-methy1-1,5-pentane diimine (BBHBPDI) on SDS coated alumina has been ...Preconcentration/separation of Co(II), Fe(III), Pb(II), Cr(IIl), Cu(II) and Cd(II) ions using bis(5-bromo- 2-hydroxy-benzaldehyde)-2-methy1-1,5-pentane diimine (BBHBPDI) on SDS coated alumina has been reported. The influences of the analytical parameters including pH, ligand and SDS amount, type and concentration of eluent and sample volume on metal ions recoveries were investigated. At optimum values of all variables the relative standard deviation are between 2.5-2.7 and preconcentration factor was 375, while recoveries for all understudy metal ions are higher than 95%, determination limits are between 1.5-2.7. The method has been successfully applied to determination of Co(II), Fe(III), Pb(II), Cr(III), Cu(II) and Cd(II) ions content in some real samples.展开更多
A kind of novel cellulose ether-trihydroxybutyl cellulose (THBC) was synthesized. The process includes the steam explosion treatment of cotton cellulose, alkalization, etherification and purification. Sweep electron m...A kind of novel cellulose ether-trihydroxybutyl cellulose (THBC) was synthesized. The process includes the steam explosion treatment of cotton cellulose, alkalization, etherification and purification. Sweep electron microscope (SEM), Fourier transform infrared (FTIR) and X-ray diffraction were used to characterize the cellulose pretreated and the product. The effects of reaction conditions (temperature, time) on the molecular substitution (S_m) were discussed. To obtain a higher degree of molecular substitution, the reaction temperature is 80 ℃, and the reaction time is 4 h.展开更多
5-Bromo-2′-deoxyuridine(BrdU)is a halogenated pyrimidine that can be incorporated into newly synthesized DNA during the S phase of the cell cycle.BrdU is widely used in fate-mapping studies of embryonic and adult neu...5-Bromo-2′-deoxyuridine(BrdU)is a halogenated pyrimidine that can be incorporated into newly synthesized DNA during the S phase of the cell cycle.BrdU is widely used in fate-mapping studies of embryonic and adult neurogenesis to identify newborn neurons,however side effects on neural stem cells and their progeny have been reported.In vivo astrocyte-to-neuron(AtN)conversion is a new approach for generating newborn neurons by directly converting endogenous astrocytes into neurons.The BrdU-labeling strategy has been used to trace astrocyte-converted neurons,but whether BrdU has any effect on the AtN conversion is unknown.Here,while conducting a NeuroD1-mediated AtN conversion study using BrdU to label dividing reactive astrocytes following ischemic injury,we accidentally discovered that BrdU inhibited AtN conversion.We initially found a gradual reduction in BrdU-labeled astrocytes during NeuroD1-mediated AtN conversion in the mouse cortex.Although most NeuroD1-infected astrocytes were converted into neurons,the number of BrdU-labeled neurons was surprisingly low.To exclude the possibility that this BrdU inhibition was caused by the ischemic injury,we conducted an in vitro AtN conversion study by overexpressing NeuroD1 in cultured cortical astrocytes in the presence or absence of BrdU.Surprisingly,we also found a significantly lower conversion rate and a smaller number of converted neurons in the BrdU-treated group compared with the untreated group.These results revealed an unexpected inhibitory effect of BrdU on AtN conversion,suggesting more caution is needed when using BrdU in AtN conversion studies and in data interpretation.展开更多
A novel method for the determination of cationic surfactant by laser thermal lens spectrometry was developed. It was based on the reaction between 1-hydroxy-2-(5-nitro-2-Pyri- dylazo)-8-aminonaphthalene-3,6-disulfoni...A novel method for the determination of cationic surfactant by laser thermal lens spectrometry was developed. It was based on the reaction between 1-hydroxy-2-(5-nitro-2-Pyri- dylazo)-8-aminonaphthalene-3,6-disulfonic acid (5-NO2-PAH) and cationic surfactant to form 1:2 ionic association complex in a weakly basic medium (pH 9.44). The determination conditions and the mechanism were discussed. The method has been applied to the analysis of wastewater and moat water samples.展开更多
Composition of bromine and nitric acid in concentrated sulfuric acid is effective for bromination of strongly deactivated aromatic compounds and for nitration and bromination of moderately deactivated compounds in one...Composition of bromine and nitric acid in concentrated sulfuric acid is effective for bromination of strongly deactivated aromatic compounds and for nitration and bromination of moderately deactivated compounds in one stage. The question why brominating agent is more reactive than nitrating agent in relation to strongly deactivated aromatic compounds and is less reactive in relation to moderate deactivated ones is discussed.展开更多
文摘The synthetic process for 2,2-dimethyl-5-nitro-5-nitroso-1,3-dioxane(DMNNDO) was improved by using tri(hydroxymethyl)nitromethane and acetone as starting materials through a "one-pot" method combined with alkaline hydrolysis and nitrosation reactions. The yield of DMNNDO was increased from 37% to 45%. The structure of DMNNDO was characterized by IR,^1H NMR,^13 C NMR,and elemental analysis. Also the thermal decomposition of DMNNDO was studied by using DSC and TG-DTG to find that there are primarily two exothermic decomposition processes between 90 and 300 oC. The crystal structure of DMNNDO was studied by X-ray single-crystal diffraction for the first time. The molecular structure exists as a dimeric form due to the presence of nitroso group. The crystal belongs to monoclinic system,space group C2/c with a = 14.515(3),b = 9.955(2),c = 11.897(2) °,β = 98.500(3)°,V = 1.6998(2) nm^3,Z = 8,D_c = 1.486 g×cm^-3,μ = 0.128 mm^-1,F(000) = 800,S = 1.055,R = 0.0358 and wR = 0.0917. In particular,DMNNDO could be easily hydrolyzed in hydrous systems and the hydrolysis mechanism in CDCl_3 was revealed by means of NMR monitoring.
文摘Kinetic and conductivity of new Schiff bases compounds such ((12Z)N-(5Z)-1-bromo-5-(phenylimino)-1H- pyrrol-2(5 H)-ylidene)benzenamine {ArN(CNBrCCHCH)NAr} (Ar = C6H5) incorporating the chelating diamino has been studied in this paper and was found a second order of this reaction. Electronic Properties using hyperchem program study has been improved for this compound such angel and bond distance, and then this compound was defining as electric conductivity and did prove to be useful for conduclively compound.
文摘Raspberry ketone {RK, 4-(4-hydroxyphenyl)butan-2-one} is a natural compound contained in raspberry, and is added to cosmetics for skin whitening. It is very important to measure the RK level in cosmetics for quality assessment, since RK structurally resembles 4-(4-hydroxyphenyl)-2-butanol, which causes leukoderma on consumers’ skin. Here, we present a simple HPLC-fluorescence method for determination of RK in a fragrance mist by pre-column derivatization with 4-hydrazino-7-nitro-2,1,3-benzoxadiazole hydrazine (NBD-H), which reacts with the carbonyl group of RK. The NBD-RK derivative was eluted from a reversed-phase ODS column, and detected with excitation at 470 nm and emission at 550 nm. The retention time of NBD-RK derivative obtained by reaction with NBD-H at 80°C for 20 min was 10.3 min. The standard curve was linear in the range of 0.2 to 10 μg/mL, with a correlation coefficient (r<sup>2</sup>) value of 0.9980. The lower limit of detection was 0.018 μg/mL (absolute amount of 1.8 pmol). The coefficients of variation were less than 8.1%. The content of RK in fragrance mist (1.00 mL) was 1.18 ± 0.07 mg (range: 1.12 to 1.28 mg, n = 5). Recovery tests were satisfactory (83.9% ± 3.9%;range: 79.6 to 88.8%, n = 5).
基金This work was supported by the Natural Science Foundation of Guangdong Province (No. 06301028)
文摘The title compound has been synthesized and characterized crystallographicaUy. It is a co-crystal consisting of two different neutral zinc(H) complexes with Hbpbm (Hbpbm = 4- bromo-2-(benzimidazol-2-yl)phenol) and Hnpbm (Hnpbm = 2-(1-butylbenzimidazol-2-yl)phenol). One is a monomeric mixed-ligand complex of [Zn(bpbm)(npbm)] 1 and the other a dimer of [Zn2(npbm)4] 2 with their ratio of 2:1. Thus the overall formula for the title compound is 21.2. Adjacent 1 and 2 are connected to each other by intermolecular hydrogen bonding interactions in the lattice. The crystal data: monoclinic, space group P21/c, a = 15.0141(12), b = 20.9941(17), c = 18.4686(15) A, β = 97.445(2)°, V = 5772.4(8) A^3, Mr= 2429.68, Z = 2, Dc = 1.398 g/cm^3,μ = 1.579 -1 mm , F(000) = 2504, R = 0.0637 and wR = 0.1771 for 6464 observed reflections (I 〉 2σ(I)). The geometrical structure for 1 has also been theoretically optimized and compared with the experimental one.
基金Supported by the National Natural Science Foundation of China (Nos. 20471026 and 20771054)the Henan Tackle Key Problem of Science and Technology (Nos. 072102270030 and 072102270034)2009GGJS-104
文摘Two new coordination polymers,{[Co(O2N-Hbtb)(phen)(H2O)3]·2H2O}n 1 and {[Cu3(O2N-btb)2(bipy)2(H2O)4]·4H2O}n 2(O2N-H3btb=5-nitro-1,2,3-benzenetricarboxylic acid,phen=1,10-phenanthroline,bipy=2,2'-bipyridine),were prepared through hydrothermal reactions of Co(Ⅱ) or Cu(Ⅱ) salt with O2N-H3btb in the presence of different auxiliary N-donor ligands.Their crystal structures were determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis and IR spectroscopy.In the two complexes,O2N-H3btb ligand acts as monodentate and bis-monodentate modes,respectively.Complex 1 displays a two-dimensional layered structure through the inter-and intramolecular hydrogen bonding interactions while complex 2 has an O2N-btb bridged one-dimensional chain which is extended into a three-dimensional network by hydrogen bonding interactions.The magnetic properties of complex 2 are investigated over the temperature range of 2~300 K and ferromagnetic interactions are observed.
文摘Due to acidic solutions aggressiveness, corrosion inhibitors use is considered to be one the most practical methods to delay metals dissolution in the said solutions. In this study benzimidazolyl derivative namely 2-cyanochalcones 2-(5-nitro-1,3-dihydrobenzimidazol-2-ylidene)-3-oxo-3-(2-oxo-2H-chromen-3-yl) propanenitrile which was synthesized was then applied as a corrosion inhibitor for copper in 1 M HNO<sub>3</sub> solution. The inhibition action of this molecule was evaluated by gravimetric and density functional theory (DFT) methods. It was found experimentally that this compound has a better inhibition performance and its adsorption on copper surface follows Langmuir adsorption isotherm. This adsorption evolves with temperature and inhibitor concentration, it is endothermic and occurs spontaneously with an increase in disorder. Corrosion kinetic parameters analysis supported by Adejo-Ekwenchi model revealed the existence of both physisorption and chemisorption. DFT calculations related that compound adsorption on copper surface is due to its electron donating and accepting capacity. The reactive regions specifying the electrophilic and nucleophilic attack sites were analyzed using Fukui and dual descriptor functions. Experimental results obtained were compared with the theoretical findings.
基金This work was supported by the National Natural Science Foundation of China (No. 20472072 and 20332060)the CAS Academician Foundation of Zhejiang Province
文摘The title compound 4-bromo-5-ethoxy-3-methyl-5-(naphthalen-l-yl)-l-tosyl-lH- pyrrol-2(5H)-one 1 (C24H22BrNO4S, Mr = 500.40) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/n with a = 8.8562(15), b = 18.118(3), c = 14.055(2)A, β = 99.855(3)^o, V= 2221.9(6)A3, Z = 4, Dc = 1.496 g/cm^3,μ= 1.975 mm^-1, 2 = 0.71073A, F(000) = 1024, R = 0.0607 and wR = 0.1371.
基金Gansu Province Science and Technology Bureau Program Funds(144FKCA065)
文摘The title compound N1-(2-(4-bromo-2-nitrophenoxy)-2-dimethyl acyloxymethyl)-5-fluorouracil(C15H13BrFN3O7, Mr = 446.19) was synthesized and structurally characterized by ^1H-NMR, -(13)C-NMR, ESI-MS and single-crystal X-ray diffraction. The compound crystallizes in triclinic, space group P1, with a = 8.3325(6), b = 10.1808(13), c = 11.8194(16) A, α = 73.194(12), β= 72.351(9), γ = 89.509(8)o, V = 911.2(2) A^3, Z = 2, T = 300.79(10) K, μ(Cu Kα) = 3.578 mm^-1, Dc = 1.626 g/cm3, F(000) = 448.0, GOF = 1.060, 5723 reflections measured(8.232≤2θ≤139.592°), 3339 unique(Rint = 0.0184, Rsigma = 0.0254) which were used in all calculations. The final R = 0.0517(I 〉 2s(I)) and wR = 0.1494(all data). Hydrogen bonds and π-π interactions together stabilize the structure of the molecule. The preliminary biological test shows that the title compound has good antitumor activity against A549 in vitro and lower toxicity to normal cells.
文摘This paper introduces the synthesis of a new color reagent 1-(6-nitro-2-benzothiazolyl)3-(4-nitrophenyl)-triazene (NBTNPT) and the color reaction of NBTNPT with Cd (II) has been studied. In the presence of Triton X-100, the reagent with Cd (II) forms an orange-yellow complex (1:1) at pH=11.5-12.3, the molar absorptivity is 2.81x10(5)L . mol(-1)m(-1) by dual-wavelength spectrophotometry, Beers law is obeyed in the range of 0-280 mu g/L for Cd (II).
文摘The title compound Ph3P=C(H)C(O)PhNO2 (L) has been prepared by the addition of triphenylphosphine in acetone as solvent to 2-bromo-1-(3,nitrophenyl)ethanone followed by the addition of alkaline solution of sodium hydroxide. The yellow crystals of the title ylide were grown in methanol/chloroform solution by drop method without stirring at room temperature. The solid state structure of ylide has been established by X-ray crystallography analysis. In the molecule of the title compound, the geometry around the P atom is nearly tetrahedral and the O atom is in synperiplanar orientation to the P atom. The nitrophenyl ring is twisted with respect to the plane of the carbonyl group through an angle of 36.6(1)°. The crystal (C26H20NO3P, Mr = 425.40) belongs to the monoclinic system, space group P21/n with a = 10.889(3), b = 14.467(3), e = 13.872(4)A, β = 103.08(3)°, V = 2128.6(10) A3, Z= 4, T= 100(2) K, R = 0.059 and wR = 0.163 for 3984 observed reflections with I〉 2σ(I).
基金ProjectsupportedbytheNationalNaturalScienceFoundationofChina (No .2 99710 2 5 )
文摘The thermal decomposition of 3-nitro-1,2,4-triazol-5-one magnesium complex and its kinetics were studied under the non-isothermal condition by DSC and TG/DTG methods. The kinetic parameters were obtained from analysis of the DSC and TG/DTG curves by the Kissinger method,the Ozawa method,the differential method and the integral method. The most probable mechanism functions for the thermal decomposition of the first stage,the second stage and the third stage were suggested by comparing the kinetic parameters. The entropy of activation (ΔS ≠),enthalpy of activation (ΔH ≠) and free energy of activation (ΔG ≠) at Tpdo are -66.74 J·mol -1 ·K -1 ,119.2 kJ·mol -1 and 152.44 kJ·mol -1 ,respectively.
文摘This article reported the distribution of DNase-1 sensitive regions in genomes of three Burkitt's lymphoma cell lines, P3HR-1, Raji and Ramos cell lines using a new method of in situ nick translation of chromosomes substituted completely by BrdU. The results showed that the Blym locus on chromosomes In three cell lines and the c-myc locus on chromosomes in P3HR-1 were the DNase-1 sensitive regions and found that the rearrangemental sites of chromosomes present in three Burkltt' s lymphoma cell lines were sensitive to DNase-1 digestion, Indicating that c-myc, bcl-1 genes located at the rearrangemental sites and the Blym gene in Burkltt' s lymphoma are the active genes having the capability of expression.
文摘Preconcentration/separation of Co(II), Fe(III), Pb(II), Cr(IIl), Cu(II) and Cd(II) ions using bis(5-bromo- 2-hydroxy-benzaldehyde)-2-methy1-1,5-pentane diimine (BBHBPDI) on SDS coated alumina has been reported. The influences of the analytical parameters including pH, ligand and SDS amount, type and concentration of eluent and sample volume on metal ions recoveries were investigated. At optimum values of all variables the relative standard deviation are between 2.5-2.7 and preconcentration factor was 375, while recoveries for all understudy metal ions are higher than 95%, determination limits are between 1.5-2.7. The method has been successfully applied to determination of Co(II), Fe(III), Pb(II), Cr(III), Cu(II) and Cd(II) ions content in some real samples.
文摘A kind of novel cellulose ether-trihydroxybutyl cellulose (THBC) was synthesized. The process includes the steam explosion treatment of cotton cellulose, alkalization, etherification and purification. Sweep electron microscope (SEM), Fourier transform infrared (FTIR) and X-ray diffraction were used to characterize the cellulose pretreated and the product. The effects of reaction conditions (temperature, time) on the molecular substitution (S_m) were discussed. To obtain a higher degree of molecular substitution, the reaction temperature is 80 ℃, and the reaction time is 4 h.
基金supported by the Natural Science Foundation of Guangdong Province of China,Nos.2021A1515011237(to WL),2020A1515010854(to QSW)the National Natural Science Foundation of China,Nos.U1801681(to GC),31701291(to WL)the Guangdong Province Science and Technology Planning Project of China,No.2018B030332001(to GC)。
文摘5-Bromo-2′-deoxyuridine(BrdU)is a halogenated pyrimidine that can be incorporated into newly synthesized DNA during the S phase of the cell cycle.BrdU is widely used in fate-mapping studies of embryonic and adult neurogenesis to identify newborn neurons,however side effects on neural stem cells and their progeny have been reported.In vivo astrocyte-to-neuron(AtN)conversion is a new approach for generating newborn neurons by directly converting endogenous astrocytes into neurons.The BrdU-labeling strategy has been used to trace astrocyte-converted neurons,but whether BrdU has any effect on the AtN conversion is unknown.Here,while conducting a NeuroD1-mediated AtN conversion study using BrdU to label dividing reactive astrocytes following ischemic injury,we accidentally discovered that BrdU inhibited AtN conversion.We initially found a gradual reduction in BrdU-labeled astrocytes during NeuroD1-mediated AtN conversion in the mouse cortex.Although most NeuroD1-infected astrocytes were converted into neurons,the number of BrdU-labeled neurons was surprisingly low.To exclude the possibility that this BrdU inhibition was caused by the ischemic injury,we conducted an in vitro AtN conversion study by overexpressing NeuroD1 in cultured cortical astrocytes in the presence or absence of BrdU.Surprisingly,we also found a significantly lower conversion rate and a smaller number of converted neurons in the BrdU-treated group compared with the untreated group.These results revealed an unexpected inhibitory effect of BrdU on AtN conversion,suggesting more caution is needed when using BrdU in AtN conversion studies and in data interpretation.
文摘A novel method for the determination of cationic surfactant by laser thermal lens spectrometry was developed. It was based on the reaction between 1-hydroxy-2-(5-nitro-2-Pyri- dylazo)-8-aminonaphthalene-3,6-disulfonic acid (5-NO2-PAH) and cationic surfactant to form 1:2 ionic association complex in a weakly basic medium (pH 9.44). The determination conditions and the mechanism were discussed. The method has been applied to the analysis of wastewater and moat water samples.
文摘Composition of bromine and nitric acid in concentrated sulfuric acid is effective for bromination of strongly deactivated aromatic compounds and for nitration and bromination of moderately deactivated compounds in one stage. The question why brominating agent is more reactive than nitrating agent in relation to strongly deactivated aromatic compounds and is less reactive in relation to moderate deactivated ones is discussed.