By using 1-methyl-2-formyl-5 -Y-substituted pyrrole (4-nitrophenyl)hydrazones as a model for nitrogen-containing heterocyclic aromatic compounds, the emission wavelength [lambda(max(em))] values df their fluorescence ...By using 1-methyl-2-formyl-5 -Y-substituted pyrrole (4-nitrophenyl)hydrazones as a model for nitrogen-containing heterocyclic aromatic compounds, the emission wavelength [lambda(max(em))] values df their fluorescence spectra have been measured. Correlation results show that the Delta E-em values are mainly affected by polar effects, but spin-delocalizatin effects also exist.展开更多
4,5-Dibromo-1-methyl-2-trichloroacetylpyrrole Ⅰ, prepared by the reaction of 1-methyl-2-trichloroacetylpyrrole with Br2 in 98.6 % yield, was condensed with methyl L-2-amino-3- phenylpropanoate to afford methyl 2-（4,...4,5-Dibromo-1-methyl-2-trichloroacetylpyrrole Ⅰ, prepared by the reaction of 1-methyl-2-trichloroacetylpyrrole with Br2 in 98.6 % yield, was condensed with methyl L-2-amino-3- phenylpropanoate to afford methyl 2-（4,5-dibromo-1-methylpyrrole-2-carboxmido）-3-phenylpropanoate Ⅱ in 90.8% yield. Crystal data for Ⅰ： monoclinic system, space group P21/c with a = 8.595（3）, b = 10.900（4）, c = 12.321（5） ,A°,β = 92.292（7）°, V = 1153.4（8）A°^3, Dc = 2.213 g/cm^3, F（000） = 728, CTH4Br2Cl3NO, Mr = 384.28, λ = 0.71073 A°, μ（MoKa） = 7.688 mm^-1, Z = 4, R = 0.0338 and wR2 = 0.0840 for 1963 observed reflections with I 〉 2a（I）. Crystal data for Ⅱ： monoclinic system, space group P21 with a = 4.886（2）, b = 15.921（8）, c = 11.635（6） A°,β = 101.803（9）°, V = 885.9（7） A°^3, Dc = 1.665 g/cm^3, F（000） = 440, C16H16Br2N2O3, Mr = 444.13, λ = 0.71073 A°, μ（MoKa） = 4.590 mm^-1, Z = 2, R = 0.0335 and wR2 = 0.0837 for 3191 observed reflections with I 〉 2σ（I）. The crystal structure reveals that compound Ⅱ forms the one-dimensional chain structure via the intermolecular hydrogen bonds of N（2）-H…O（1）.展开更多
Mono-substituted heterocyclic ketene aminals are formed by the reaction of 1-methyl-2-methylthio-imidazoline with active methylene compounds containinq an acetyl or benzoyl group by the elimination of both a methylthi...Mono-substituted heterocyclic ketene aminals are formed by the reaction of 1-methyl-2-methylthio-imidazoline with active methylene compounds containinq an acetyl or benzoyl group by the elimination of both a methylthio and an acyl group.This is resulted by the secondary reactio of the produced methanethiol to attack the more active carbonyl group.展开更多
Sodium 3,5-bis(hydroxyimino)-1-methyl-2,4,6-trioxocyclohexanide C7H5N2NaO5 (I) has been isolated as the only product of the reaction of nitrosation of methylphloroglucinol. The structure of the titled compound has bee...Sodium 3,5-bis(hydroxyimino)-1-methyl-2,4,6-trioxocyclohexanide C7H5N2NaO5 (I) has been isolated as the only product of the reaction of nitrosation of methylphloroglucinol. The structure of the titled compound has been determined from single crystal X-ray diffraction data. The hydrated C7H5N2NaO52.5H2O crystallizes in the monoclinic space group C2/c, with a(?) 16.408(3);b(?) 12.446(3);c(?) 13.716(3);(o) 126.34(3). The planar organic anion exists in a triketo-dihydroxyimino form with the C–O and C–N distances from 1.220(2) to 1.271(2)?? and from 1.292(2) to 1.293?? respectively. In the IR spectrum of I, the sharp absorption band occurred at 1681 cm-1 due to C=O stretching indicating the strong H-interactions. The correlations of theoretical (DFT-B3LYP/aug-cc-pVDZ) and experimental UV-vis absorption spectra in neutral and alkaline ethanolic solutions showed the existence of hydroxyimino-nitroso tautomerism while ionization of I.展开更多
The catalysis technology of propylene dimerization to form 4-methyl-1-pentene(4MP1)using a Cu-K/K_(2)CO_(3) solid base catalyst is a well-known heterogeneous catalytic reaction.In this study,the intrinsic kinetics of ...The catalysis technology of propylene dimerization to form 4-methyl-1-pentene(4MP1)using a Cu-K/K_(2)CO_(3) solid base catalyst is a well-known heterogeneous catalytic reaction.In this study,the intrinsic kinetics of propylene dimerization were studied in a fixed-bed continuous reactor.Internal and external diffusion during the dimerization reaction experiments were eliminated by adjusting the flow rate of the carrier gas and the particle size of the catalyst support.Then,the concentration changes of each substance at the outlet of the catalyst bed under different residence times were investigated.Moreover,the suitable reaction kinetics equations was derived using the Langmuir Hinshelwood-Hougen-Watson kinetic model.Finally,the activation energy for each reaction involved in the dimerization reaction was calculated.The activation energies of 4MP1,branched by-products,and 1-hexene were 115.0,150.8,and 177.4 kJ/mol,respectively.The effect of process conditions on propylene dimerization with solid base catalysts was studied through kinetic model simulation.By comparing the theoretical values obtained from the simulation with the experimental results,the applicability and accuracy of the kinetic model were verified.展开更多
文摘By using 1-methyl-2-formyl-5 -Y-substituted pyrrole (4-nitrophenyl)hydrazones as a model for nitrogen-containing heterocyclic aromatic compounds, the emission wavelength [lambda(max(em))] values df their fluorescence spectra have been measured. Correlation results show that the Delta E-em values are mainly affected by polar effects, but spin-delocalizatin effects also exist.
基金The project was supported by the National 863 Program of China (No. 2004AA628030), and Natural Science Foundation of Guangdong Province (No. 31920)
文摘4,5-Dibromo-1-methyl-2-trichloroacetylpyrrole Ⅰ, prepared by the reaction of 1-methyl-2-trichloroacetylpyrrole with Br2 in 98.6 % yield, was condensed with methyl L-2-amino-3- phenylpropanoate to afford methyl 2-（4,5-dibromo-1-methylpyrrole-2-carboxmido）-3-phenylpropanoate Ⅱ in 90.8% yield. Crystal data for Ⅰ： monoclinic system, space group P21/c with a = 8.595（3）, b = 10.900（4）, c = 12.321（5） ,A°,β = 92.292（7）°, V = 1153.4（8）A°^3, Dc = 2.213 g/cm^3, F（000） = 728, CTH4Br2Cl3NO, Mr = 384.28, λ = 0.71073 A°, μ（MoKa） = 7.688 mm^-1, Z = 4, R = 0.0338 and wR2 = 0.0840 for 1963 observed reflections with I 〉 2a（I）. Crystal data for Ⅱ： monoclinic system, space group P21 with a = 4.886（2）, b = 15.921（8）, c = 11.635（6） A°,β = 101.803（9）°, V = 885.9（7） A°^3, Dc = 1.665 g/cm^3, F（000） = 440, C16H16Br2N2O3, Mr = 444.13, λ = 0.71073 A°, μ（MoKa） = 4.590 mm^-1, Z = 2, R = 0.0335 and wR2 = 0.0837 for 3191 observed reflections with I 〉 2σ（I）. The crystal structure reveals that compound Ⅱ forms the one-dimensional chain structure via the intermolecular hydrogen bonds of N（2）-H…O（1）.
文摘Mono-substituted heterocyclic ketene aminals are formed by the reaction of 1-methyl-2-methylthio-imidazoline with active methylene compounds containinq an acetyl or benzoyl group by the elimination of both a methylthio and an acyl group.This is resulted by the secondary reactio of the produced methanethiol to attack the more active carbonyl group.
文摘Sodium 3,5-bis(hydroxyimino)-1-methyl-2,4,6-trioxocyclohexanide C7H5N2NaO5 (I) has been isolated as the only product of the reaction of nitrosation of methylphloroglucinol. The structure of the titled compound has been determined from single crystal X-ray diffraction data. The hydrated C7H5N2NaO52.5H2O crystallizes in the monoclinic space group C2/c, with a(?) 16.408(3);b(?) 12.446(3);c(?) 13.716(3);(o) 126.34(3). The planar organic anion exists in a triketo-dihydroxyimino form with the C–O and C–N distances from 1.220(2) to 1.271(2)?? and from 1.292(2) to 1.293?? respectively. In the IR spectrum of I, the sharp absorption band occurred at 1681 cm-1 due to C=O stretching indicating the strong H-interactions. The correlations of theoretical (DFT-B3LYP/aug-cc-pVDZ) and experimental UV-vis absorption spectra in neutral and alkaline ethanolic solutions showed the existence of hydroxyimino-nitroso tautomerism while ionization of I.
基金supported by the National Natural Science Foundation of China under agreement number 22378026the Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges under Beijing Municipality(IDHT20180508).
文摘The catalysis technology of propylene dimerization to form 4-methyl-1-pentene(4MP1)using a Cu-K/K_(2)CO_(3) solid base catalyst is a well-known heterogeneous catalytic reaction.In this study,the intrinsic kinetics of propylene dimerization were studied in a fixed-bed continuous reactor.Internal and external diffusion during the dimerization reaction experiments were eliminated by adjusting the flow rate of the carrier gas and the particle size of the catalyst support.Then,the concentration changes of each substance at the outlet of the catalyst bed under different residence times were investigated.Moreover,the suitable reaction kinetics equations was derived using the Langmuir Hinshelwood-Hougen-Watson kinetic model.Finally,the activation energy for each reaction involved in the dimerization reaction was calculated.The activation energies of 4MP1,branched by-products,and 1-hexene were 115.0,150.8,and 177.4 kJ/mol,respectively.The effect of process conditions on propylene dimerization with solid base catalysts was studied through kinetic model simulation.By comparing the theoretical values obtained from the simulation with the experimental results,the applicability and accuracy of the kinetic model were verified.
