Synthesis of the title compound was carried out by base-catalyzed cyclization of 1-pivaloyl-3-(2-chloro-4-nitrophenyl) thiourea with α-bromoacetone produced in situ. The structure was confirmed by the spectroscopic a...Synthesis of the title compound was carried out by base-catalyzed cyclization of 1-pivaloyl-3-(2-chloro-4-nitrophenyl) thiourea with α-bromoacetone produced in situ. The structure was confirmed by the spectroscopic and elemental analysis and single crystal X-ray diffraction data. It crystallizes in the triclinic space group P-1 with unit cell dime sions a = 8.7137(10), b = 10.2010(14), c = 10.6593(13), α = 62.671(9), β = 82.701(10), γ = 79.762(10), V = 827.21(8) ?3, Z = 2.展开更多
The title compound N-（（3-（2-nitrophenyl） propanoyl）oxy）-N-phenylbenzamide（C22H18N2O5,Mr = 390.38） was synthesized with nitrobenzene as the starting materials and structurally characterized by 1H NMR,13 C NMR,I...The title compound N-（（3-（2-nitrophenyl） propanoyl）oxy）-N-phenylbenzamide（C22H18N2O5,Mr = 390.38） was synthesized with nitrobenzene as the starting materials and structurally characterized by 1H NMR,13 C NMR,IR,H RMS（E-SI） and single-crystal X-ray diffraction.The crystalline structure of the title compound was studied in detail.The single-crystal X-ray diffraction revealed that the compound crystallizes in monoclinic,space group P21/n,with a = 14.4481（7）,b = 8.0089（5）,c = 16.6808（9） A,α = 90.00（5）,β = 100.069（5）,γ = 90.00（5）°,Mr = 390.38,V = 1900.46（18） A^3,Z = 4,Dc = 1.364 g/cm^-3,μ = 0.098,F（000） = 816.0,the final R = 0.0530 and w R = 0.1141 for 2525 observed reflections（I 〉 2σ（I））,R（all data） = 0.0813,w R（all data） = 0.1335,completeness to theta of 26.020 is 99.8% and GOF = 1.085.The crystal structure contains three branched chains with its center placed at the midpoint of N.The phenyl ring（C（8）~C（13）） makes a dihedral angle of 83.5（1） ℃ with the phenyl ring（C（1）~C（6））,and 80.5（1） ℃with the nitro-substituted benzene ring（C（17）~C（22））,indicating that the three rings are not coplanar.Hydrogen bonds（C（10）–H（10）···O（3））,（C（15）–H（15B）···O（4） and C（16）–H（16B）···O（4）） together with π-π stacking interactions stabilize the structure of the molecule.The preliminary biological test shows that the title compound has good antitumor activity against A549 in vitro with the IC50 value of 3.17 μmol.展开更多
Polymeric β-cyclodextrin (β-CD) supported by crosslinked poly(acrylamide-co-vinylamine) was synthesized as anartificial analog of hydrolytic enzyme and its catalysis of the hydrolysis of p-nitrophenyl acetate (p-NPA...Polymeric β-cyclodextrin (β-CD) supported by crosslinked poly(acrylamide-co-vinylamine) was synthesized as anartificial analog of hydrolytic enzyme and its catalysis of the hydrolysis of p-nitrophenyl acetate (p-NPA) was theninvestigated. The result showed that the polymer-supported β-CD could accelerate the hydrolytic reaction of p-NPA morequickly than β-CD itself and crosslinked poly(acrylamide-co-vinylamine) alone. The acceleration rate of the polymer-supported β-CD was about 10 times as fast as that of free β-CD in 0.01 mol/L phosphate buffer (pH 7.4) containing 32%DMSO at 37±0.1℃ when the molar amount of β-CD units in the polymer was equal to that of free β-CD in the experiments.The enhanced acceleration of thc polymer-supported β-CD should be ascribed to the cooperative contribution of theinclusion effect of β-CD ring and the nucleophilic effect of amino groups on the polymeric support.展开更多
A colorimetric method for the direct determination of hydrogen peroxide in aqueous solution is described. H2O2 stoichiometrically converts 4-nitrophenyl boronic acid or 4-nitrophenyl boronic acid pinacol ester into 4-...A colorimetric method for the direct determination of hydrogen peroxide in aqueous solution is described. H2O2 stoichiometrically converts 4-nitrophenyl boronic acid or 4-nitrophenyl boronic acid pinacol ester into 4-nitrophenol, which can be quantified by measuring the absorption at 400 nm in neutral or basic media. The reactions proceed fast under basic conditions and complete in 2 minutes to at pH 11 and 80?C. The linear range for the colorimetric method extends beyond 1.0 to 40 μM H2O2, and the limit of detection is ~1.0 μM H2O2. This method offers a convenient and practical process for rapid determination of hydrogen peroxide in aqueous media. Compared to many other techniques in H2O2 detection, this process is a direct measurement of H2O2, and is relatively unaffected by the presence of various salts, metal ions and the chelator EDTA.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
Large crystal NPP-OTs has been obtained by growth from solution,its powder SHG efficiency is 1/3 of urea.It shows it is a new convenient approach to obtain organic second-order NLO crystal:the dipole-dipole interactio...Large crystal NPP-OTs has been obtained by growth from solution,its powder SHG efficiency is 1/3 of urea.It shows it is a new convenient approach to obtain organic second-order NLO crystal:the dipole-dipole interaction is oppos- ed by introducing a large side group.展开更多
Novel compounds, （3,6-dichloro-2-nitrophenyl）（3-nitrophenyl）methanone（2）, （2-amino-3,6-dichloro- phenyl）（3-aminophenyl）methanone（3） and 1-[3-（2-amino-3,6-dichlorobenzoyl）phenyl]-1H-pyrrole-2,5-dione（4）...Novel compounds, （3,6-dichloro-2-nitrophenyl）（3-nitrophenyl）methanone（2）, （2-amino-3,6-dichloro- phenyl）（3-aminophenyl）methanone（3） and 1-[3-（2-amino-3,6-dichlorobenzoyl）phenyl]-1H-pyrrole-2,5-dione（4）, were synthesized from the initial compound 2,5-dichlorobenzophenone（1） and characterized by 1H NMR, 13C NMR, IR, mass spectrum and element analysis, respectively. The single crystal of compound 2 was obtained and determined by X-ray diffraction analysis. The single crystal data illustrates that it belongs to the monoclinic system, space group P21/c with a=0.7587（4） nm, b=2.4724（4） nm, c=0.8081（3） nm, α=90°, β=112.85（2）°, γ=90o, V=1.3970（9） nm3, Z=4, Dc=1.622 g/cm3, Mr（C13H6Cl2N2O5）=341.10, μ（Mo Kα）=0.49 mm？1, F（000）=688, the final R=0.048 and wR=0.144 for 1665 observed reflections with I2σ（I）. The title molecule forms a ＂T＂ type crystal structure and the dihedral angel of the two phenyl rings is 65.0（1）°.展开更多
The new title compound 4-chloro-N-（2-（2-nitrophenyl）acetoxy）-N-（m-tolyl）benza- mide （C：2HI7C1N2Os, Mr = 424.82） has been synthesized via the reaction of 4-chloro-N-hydroxy-N- （m-tolyl）benzamide with 2-（2-n...The new title compound 4-chloro-N-（2-（2-nitrophenyl）acetoxy）-N-（m-tolyl）benza- mide （C：2HI7C1N2Os, Mr = 424.82） has been synthesized via the reaction of 4-chloro-N-hydroxy-N- （m-tolyl）benzamide with 2-（2-nitrophenyl）acetyl chloride. The structure of the product was confirmed by 1H NMR, 13C NMR, IR, HRMS （ESI） and single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group P21/c with a = 13.0269（10）, b =6.7251（6）, c = 23.9313（16） A, β = 99.931（6）°, V = 2065.1（3） A3, Z = 4, Dc = 1.366 g/cm3, F（000） = 880,μ = 0.221 mm-1, the final R = 0.0600 and wR = 0.1754 for 1981 observed reflections （I〉 20（/））. X-ray analysis indicates that the chloro-phenyl ring （C（10）℃（15）） and the methyl-substituted benzene ring （C（16）℃（21）） are not coplanar with the nitro-substituted benzene ring （C（1）--C（6））, with the dihedral angle to be 70.78° and 63.72°, respectively. Hydrogen bonds C（2）-H（2）...O（2） and C（7）-H（7B）...O（5） are observed.展开更多
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
The title compound 2-（2-chloro-4-nitrophenyl）-4-（4-chlorophenyl）-3a,4- diethoxy- 2,3,3a, 4-tetrahydrochromeno[3,4-d][1,2,3]diazaphosphole 2 （C29H30Cl2N3O7P, Mr = 633.44） was synthesized and its structure was cha...The title compound 2-（2-chloro-4-nitrophenyl）-4-（4-chlorophenyl）-3a,4- diethoxy- 2,3,3a, 4-tetrahydrochromeno[3,4-d][1,2,3]diazaphosphole 2 （C29H30Cl2N3O7P, Mr = 633.44） was synthesized and its structure was characterized by IR, MS, ^1H NMR, ^13C NMR, ^31p NMR, elemental analysis and single-crystal X-ray diffraction. It crystallizes in triclinic, space group P1^-, a = 9.1549（3）, b = 10.7168（4）, c = 17.6272（6）A, α = 102.9363（12）, β = 90.2713（9）, γ = 117.4265（10）°, V= 1484.41（9）A^3, Z= 2,μ（MoKa） = 0.323, F（000） = 658, Z= 2, De= 1.417 g/cm^3, the final R = 0.0687 and wR = 0.2066 for 4943 observed reflections （I 〉 2σ（I））. X-ray analysis reveals that the diazaphospholine ring is almost planar and the two ethoxy groups bonded on the 3a- and 4-positions are in trans configurations. Its antiproliferative activity was also tested in vitro against four human tumor cell lines.展开更多
Compact and high reliable blue coherent light sources are required for the optical data storage of high density, color image processing and optical measurements.One of the possible approaches is the direct frequency d...Compact and high reliable blue coherent light sources are required for the optical data storage of high density, color image processing and optical measurements.One of the possible approaches is the direct frequency doubling of the near infrared semiconductor laser by optical waveguide techniques. So a material applied to the second harmonic generation (SHG) must not only have high molecular hyperpolarizability (β) but also have complete transparency at both the展开更多
This paper describes the catalytic performance of two manganese（III） complexes with mono-Schiff base ligands as artificial hydrolases towards the hydrolysis of p-nitrophenyl picolinate （PNPP）. Observations reveal ...This paper describes the catalytic performance of two manganese（III） complexes with mono-Schiff base ligands as artificial hydrolases towards the hydrolysis of p-nitrophenyl picolinate （PNPP）. Observations reveal that the one complex （ MnL22C1 ） containing morpholine pendants exhibits 1.2-1.7 fold kinetic advantage over the other one （MnL12C1） containing benzoaza-15-crown-5 group. Especially, optimum molecule structures using a Gaussian 03 software confirm that MnL2CI indeed possesses a relatively open linked site for the approaching of PNPP, result- ing in higher efficiency due to a convenient association between substrate （PNPP） and MnL2C1. In addition, the steric hindrance of two pendants, i.e., benzoaza-15-crown-5 and morpholine, may be a main influencing factor for tuning catalytic activities of the synthesized Mn（III） catalysts. Both Mn（III） catalysts used here were found to have fine tolerance to the operated temperature and pH. Related kinetic and thermodynamic analyses were also given to demonstrate their structure-activity relationships （SAR） of both catalysts used.展开更多
Studies on fullerenes have been made extensively since the method of macroscopic synthesis of fullerenes was proposed in 1990, and synthesis and structure of organic derivatives of buckminsterfullerene continue to att...Studies on fullerenes have been made extensively since the method of macroscopic synthesis of fullerenes was proposed in 1990, and synthesis and structure of organic derivatives of buckminsterfullerene continue to attract interest of broad scientific community. The chemical reactivity of buckminsterfullerene (C<sub>60</sub>) is an area of vigorous investigation. It has been suggested that C<sub>60</sub> acts like a closed-cage alkene rather than展开更多
The hydrolysis of p-nitrophenyl acetate (p-NPA) catalyzed by seryl-histidine or histidine has been monitored by electrospray ionization mass spectrometry in the presence of the internal calibration, 8-anilino-1-naphth...The hydrolysis of p-nitrophenyl acetate (p-NPA) catalyzed by seryl-histidine or histidine has been monitored by electrospray ionization mass spectrometry in the presence of the internal calibration, 8-anilino-1-naphthalenesulfonic acid ammonium salt (ANS). The half-life of p-NPA in the presence of 10 mmol·L -1 seryl-histidine or histidine at 25 ℃ was 370 min and 70 min respectively. With the occurrence of acetyl seryl-histidine and acetyl histidine in the reaction, and the fact that p-NPA was stable in the presence of 10 mmol·L -1 serine, an imidazolysis mechanism has been proposed, which is in accordance with the reported work.展开更多
Two long-chain multidentate ligands： 2,9-di-（n-2＇,5＇,8＇-triazanonyl）-1,10-phenanthroline （L^1） and 2,9-di- （n-4＇,7＇,10＇-triazaundecyl）-1,10-phenanthroline （L^2） were synthesized. The hydrolytic kinetics...Two long-chain multidentate ligands： 2,9-di-（n-2＇,5＇,8＇-triazanonyl）-1,10-phenanthroline （L^1） and 2,9-di- （n-4＇,7＇,10＇-triazaundecyl）-1,10-phenanthroline （L^2） were synthesized. The hydrolytic kinetics of 2-hydroxypropyl p-nitrophenyl phosphate （HPNP） catalyzed by the complexes of L^1 or L^2 with La（Ⅲ） or Gd（Ⅲ） have been studied in aqueous solution at （298.2±0.1） K, I=0.10 mol·dm^-3 KNO3 in pH 7.5-9.1, respectively, finding that the catalytic effect of GdL^1 was the best among the four complexes for hydrolysis of HPNP. Its kLnLH-1, kLnLand pKa are 0.047 mol^-1·L·s^-1, 0.000074 mol^-1·L·s^-1 and 8.90, respectively. This paper expounded the studied result with the structure of the ligands and the properties of the metal ions, and deduced the catalysis mechanism.展开更多
The unsymmetrical bis-Schiff base manganese（III） and cobalt（II） complexes with either benzo-10-aza-crown ether pendants （MnL1Cl, MnLZCl） or morpholino pendant （MnL3Cl, CoL3） have been employed as models for hy...The unsymmetrical bis-Schiff base manganese（III） and cobalt（II） complexes with either benzo-10-aza-crown ether pendants （MnL1Cl, MnLZCl） or morpholino pendant （MnL3Cl, CoL3） have been employed as models for hy- drolase by studying the kinetics of their hydrolysis reactions with p-nitrophenyl picolinate （PNPP）. A kinetic model of PNPP cleavage catalyzed by these complexes is proposed. The effects of complex structures and reaction temperature on the rate of PNPP hydrolysis have been examined. All four complexes exhibit high catalytic activity and the rate increases with pH under 25℃. The complexes of ligands containing a crown ether group exhibit higher catalytic activities than the non-crown analogues. The catalytic activity of the complexes follows the order Mn（III） 〉 Co（II） under the same ligands.展开更多
文摘Synthesis of the title compound was carried out by base-catalyzed cyclization of 1-pivaloyl-3-(2-chloro-4-nitrophenyl) thiourea with α-bromoacetone produced in situ. The structure was confirmed by the spectroscopic and elemental analysis and single crystal X-ray diffraction data. It crystallizes in the triclinic space group P-1 with unit cell dime sions a = 8.7137(10), b = 10.2010(14), c = 10.6593(13), α = 62.671(9), β = 82.701(10), γ = 79.762(10), V = 827.21(8) ?3, Z = 2.
基金Supported by the Lanzhou Science and Technology Bureau Program Funds(2013-4-79,2014-1-174,2014-1-214)
文摘The title compound N-（（3-（2-nitrophenyl） propanoyl）oxy）-N-phenylbenzamide（C22H18N2O5,Mr = 390.38） was synthesized with nitrobenzene as the starting materials and structurally characterized by 1H NMR,13 C NMR,IR,H RMS（E-SI） and single-crystal X-ray diffraction.The crystalline structure of the title compound was studied in detail.The single-crystal X-ray diffraction revealed that the compound crystallizes in monoclinic,space group P21/n,with a = 14.4481（7）,b = 8.0089（5）,c = 16.6808（9） A,α = 90.00（5）,β = 100.069（5）,γ = 90.00（5）°,Mr = 390.38,V = 1900.46（18） A^3,Z = 4,Dc = 1.364 g/cm^-3,μ = 0.098,F（000） = 816.0,the final R = 0.0530 and w R = 0.1141 for 2525 observed reflections（I 〉 2σ（I））,R（all data） = 0.0813,w R（all data） = 0.1335,completeness to theta of 26.020 is 99.8% and GOF = 1.085.The crystal structure contains three branched chains with its center placed at the midpoint of N.The phenyl ring（C（8）~C（13）） makes a dihedral angle of 83.5（1） ℃ with the phenyl ring（C（1）~C（6））,and 80.5（1） ℃with the nitro-substituted benzene ring（C（17）~C（22））,indicating that the three rings are not coplanar.Hydrogen bonds（C（10）–H（10）···O（3））,（C（15）–H（15B）···O（4） and C（16）–H（16B）···O（4）） together with π-π stacking interactions stabilize the structure of the molecule.The preliminary biological test shows that the title compound has good antitumor activity against A549 in vitro with the IC50 value of 3.17 μmol.
文摘Polymeric β-cyclodextrin (β-CD) supported by crosslinked poly(acrylamide-co-vinylamine) was synthesized as anartificial analog of hydrolytic enzyme and its catalysis of the hydrolysis of p-nitrophenyl acetate (p-NPA) was theninvestigated. The result showed that the polymer-supported β-CD could accelerate the hydrolytic reaction of p-NPA morequickly than β-CD itself and crosslinked poly(acrylamide-co-vinylamine) alone. The acceleration rate of the polymer-supported β-CD was about 10 times as fast as that of free β-CD in 0.01 mol/L phosphate buffer (pH 7.4) containing 32%DMSO at 37±0.1℃ when the molar amount of β-CD units in the polymer was equal to that of free β-CD in the experiments.The enhanced acceleration of thc polymer-supported β-CD should be ascribed to the cooperative contribution of theinclusion effect of β-CD ring and the nucleophilic effect of amino groups on the polymeric support.
文摘A colorimetric method for the direct determination of hydrogen peroxide in aqueous solution is described. H2O2 stoichiometrically converts 4-nitrophenyl boronic acid or 4-nitrophenyl boronic acid pinacol ester into 4-nitrophenol, which can be quantified by measuring the absorption at 400 nm in neutral or basic media. The reactions proceed fast under basic conditions and complete in 2 minutes to at pH 11 and 80?C. The linear range for the colorimetric method extends beyond 1.0 to 40 μM H2O2, and the limit of detection is ~1.0 μM H2O2. This method offers a convenient and practical process for rapid determination of hydrogen peroxide in aqueous media. Compared to many other techniques in H2O2 detection, this process is a direct measurement of H2O2, and is relatively unaffected by the presence of various salts, metal ions and the chelator EDTA.
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）.
文摘Large crystal NPP-OTs has been obtained by growth from solution,its powder SHG efficiency is 1/3 of urea.It shows it is a new convenient approach to obtain organic second-order NLO crystal:the dipole-dipole interaction is oppos- ed by introducing a large side group.
文摘Novel compounds, （3,6-dichloro-2-nitrophenyl）（3-nitrophenyl）methanone（2）, （2-amino-3,6-dichloro- phenyl）（3-aminophenyl）methanone（3） and 1-[3-（2-amino-3,6-dichlorobenzoyl）phenyl]-1H-pyrrole-2,5-dione（4）, were synthesized from the initial compound 2,5-dichlorobenzophenone（1） and characterized by 1H NMR, 13C NMR, IR, mass spectrum and element analysis, respectively. The single crystal of compound 2 was obtained and determined by X-ray diffraction analysis. The single crystal data illustrates that it belongs to the monoclinic system, space group P21/c with a=0.7587（4） nm, b=2.4724（4） nm, c=0.8081（3） nm, α=90°, β=112.85（2）°, γ=90o, V=1.3970（9） nm3, Z=4, Dc=1.622 g/cm3, Mr（C13H6Cl2N2O5）=341.10, μ（Mo Kα）=0.49 mm？1, F（000）=688, the final R=0.048 and wR=0.144 for 1665 observed reflections with I2σ（I）. The title molecule forms a ＂T＂ type crystal structure and the dihedral angel of the two phenyl rings is 65.0（1）°.
基金Supported by the Fundamental Research Funds for the Central Universities(lzujbky-2010-137)Lanzhou Science and Technology Bureau Program Funds(2012-2-90)
文摘The new title compound 4-chloro-N-（2-（2-nitrophenyl）acetoxy）-N-（m-tolyl）benza- mide （C：2HI7C1N2Os, Mr = 424.82） has been synthesized via the reaction of 4-chloro-N-hydroxy-N- （m-tolyl）benzamide with 2-（2-nitrophenyl）acetyl chloride. The structure of the product was confirmed by 1H NMR, 13C NMR, IR, HRMS （ESI） and single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group P21/c with a = 13.0269（10）, b =6.7251（6）, c = 23.9313（16） A, β = 99.931（6）°, V = 2065.1（3） A3, Z = 4, Dc = 1.366 g/cm3, F（000） = 880,μ = 0.221 mm-1, the final R = 0.0600 and wR = 0.1754 for 1981 observed reflections （I〉 20（/））. X-ray analysis indicates that the chloro-phenyl ring （C（10）℃（15）） and the methyl-substituted benzene ring （C（16）℃（21）） are not coplanar with the nitro-substituted benzene ring （C（1）--C（6））, with the dihedral angle to be 70.78° and 63.72°, respectively. Hydrogen bonds C（2）-H（2）...O（2） and C（7）-H（7B）...O（5） are observed.
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.
文摘The title compound 2-（2-chloro-4-nitrophenyl）-4-（4-chlorophenyl）-3a,4- diethoxy- 2,3,3a, 4-tetrahydrochromeno[3,4-d][1,2,3]diazaphosphole 2 （C29H30Cl2N3O7P, Mr = 633.44） was synthesized and its structure was characterized by IR, MS, ^1H NMR, ^13C NMR, ^31p NMR, elemental analysis and single-crystal X-ray diffraction. It crystallizes in triclinic, space group P1^-, a = 9.1549（3）, b = 10.7168（4）, c = 17.6272（6）A, α = 102.9363（12）, β = 90.2713（9）, γ = 117.4265（10）°, V= 1484.41（9）A^3, Z= 2,μ（MoKa） = 0.323, F（000） = 658, Z= 2, De= 1.417 g/cm^3, the final R = 0.0687 and wR = 0.2066 for 4943 observed reflections （I 〉 2σ（I））. X-ray analysis reveals that the diazaphospholine ring is almost planar and the two ethoxy groups bonded on the 3a- and 4-positions are in trans configurations. Its antiproliferative activity was also tested in vitro against four human tumor cell lines.
基金Project supported by the National Natural Science Foundation of China.
文摘Compact and high reliable blue coherent light sources are required for the optical data storage of high density, color image processing and optical measurements.One of the possible approaches is the direct frequency doubling of the near infrared semiconductor laser by optical waveguide techniques. So a material applied to the second harmonic generation (SHG) must not only have high molecular hyperpolarizability (β) but also have complete transparency at both the
文摘This paper describes the catalytic performance of two manganese（III） complexes with mono-Schiff base ligands as artificial hydrolases towards the hydrolysis of p-nitrophenyl picolinate （PNPP）. Observations reveal that the one complex （ MnL22C1 ） containing morpholine pendants exhibits 1.2-1.7 fold kinetic advantage over the other one （MnL12C1） containing benzoaza-15-crown-5 group. Especially, optimum molecule structures using a Gaussian 03 software confirm that MnL2CI indeed possesses a relatively open linked site for the approaching of PNPP, result- ing in higher efficiency due to a convenient association between substrate （PNPP） and MnL2C1. In addition, the steric hindrance of two pendants, i.e., benzoaza-15-crown-5 and morpholine, may be a main influencing factor for tuning catalytic activities of the synthesized Mn（III） catalysts. Both Mn（III） catalysts used here were found to have fine tolerance to the operated temperature and pH. Related kinetic and thermodynamic analyses were also given to demonstrate their structure-activity relationships （SAR） of both catalysts used.
文摘Studies on fullerenes have been made extensively since the method of macroscopic synthesis of fullerenes was proposed in 1990, and synthesis and structure of organic derivatives of buckminsterfullerene continue to attract interest of broad scientific community. The chemical reactivity of buckminsterfullerene (C<sub>60</sub>) is an area of vigorous investigation. It has been suggested that C<sub>60</sub> acts like a closed-cage alkene rather than
文摘The hydrolysis of p-nitrophenyl acetate (p-NPA) catalyzed by seryl-histidine or histidine has been monitored by electrospray ionization mass spectrometry in the presence of the internal calibration, 8-anilino-1-naphthalenesulfonic acid ammonium salt (ANS). The half-life of p-NPA in the presence of 10 mmol·L -1 seryl-histidine or histidine at 25 ℃ was 370 min and 70 min respectively. With the occurrence of acetyl seryl-histidine and acetyl histidine in the reaction, and the fact that p-NPA was stable in the presence of 10 mmol·L -1 serine, an imidazolysis mechanism has been proposed, which is in accordance with the reported work.
基金Project supported by the National Natural Science Foundation of China （Nos. 20371028, 20671052）.
文摘Two long-chain multidentate ligands： 2,9-di-（n-2＇,5＇,8＇-triazanonyl）-1,10-phenanthroline （L^1） and 2,9-di- （n-4＇,7＇,10＇-triazaundecyl）-1,10-phenanthroline （L^2） were synthesized. The hydrolytic kinetics of 2-hydroxypropyl p-nitrophenyl phosphate （HPNP） catalyzed by the complexes of L^1 or L^2 with La（Ⅲ） or Gd（Ⅲ） have been studied in aqueous solution at （298.2±0.1） K, I=0.10 mol·dm^-3 KNO3 in pH 7.5-9.1, respectively, finding that the catalytic effect of GdL^1 was the best among the four complexes for hydrolysis of HPNP. Its kLnLH-1, kLnLand pKa are 0.047 mol^-1·L·s^-1, 0.000074 mol^-1·L·s^-1 and 8.90, respectively. This paper expounded the studied result with the structure of the ligands and the properties of the metal ions, and deduced the catalysis mechanism.
文摘The unsymmetrical bis-Schiff base manganese（III） and cobalt（II） complexes with either benzo-10-aza-crown ether pendants （MnL1Cl, MnLZCl） or morpholino pendant （MnL3Cl, CoL3） have been employed as models for hy- drolase by studying the kinetics of their hydrolysis reactions with p-nitrophenyl picolinate （PNPP）. A kinetic model of PNPP cleavage catalyzed by these complexes is proposed. The effects of complex structures and reaction temperature on the rate of PNPP hydrolysis have been examined. All four complexes exhibit high catalytic activity and the rate increases with pH under 25℃. The complexes of ligands containing a crown ether group exhibit higher catalytic activities than the non-crown analogues. The catalytic activity of the complexes follows the order Mn（III） 〉 Co（II） under the same ligands.
