The effect of 2-butyne-1, 4-diol on silver electrodeposition process from 5, 5-dimethyl hydantoin solutions was investigated by means of cyclic voltammetric measurement, scanning electron microscopy (SEM) and X-ray di...The effect of 2-butyne-1, 4-diol on silver electrodeposition process from 5, 5-dimethyl hydantoin solutions was investigated by means of cyclic voltammetric measurement, scanning electron microscopy (SEM) and X-ray diffraction (XRD). Cyclic voltammetric studies indicate that the reduction process of silver electrodeposition is influenced by adding 2-butyne-1, 4-diol. Owing to its adsorption on the electrode surface, 2-butyne-1, 4-diol moderately hinders the mass transfer of the silver complexed ions from the bulk solution to the outer limit of the electrode double layer and affects the electrocrystallization step. Scanning electron microscopy analysis reveals that the presence of 2-butyne-1, 4-diol in the electrolyte is beneficial and the silver deposits obtained are smoother, more compact and more leveled. X-ray diffraction analysis of the silver deposits obtained at 0.5 g·L-1 2-butyne-1, 4-diol indicated that the (110) plane is the most preferred plane and is not affected by the presence of 2-butyne-1, 4-diol in the electrolyte.展开更多
Eight rare earth metal （ Ⅲ ） complexes with 2- （ （（4,6-dimethyl）-2-pyrimidinyl） thio）-acetic acid, LnL3· n H2O [HL = 2-（（（4,6-dimethyl）-2-pyrimidinyl）thio）-acetic acid; Ln = La, Ce, Pr, Nd, Sm Eu, ...Eight rare earth metal （ Ⅲ ） complexes with 2- （ （（4,6-dimethyl）-2-pyrimidinyl） thio）-acetic acid, LnL3· n H2O [HL = 2-（（（4,6-dimethyl）-2-pyrimidinyl）thio）-acetic acid; Ln = La, Ce, Pr, Nd, Sm Eu, Gd, Tb; n = 4 or 5], were prepared and characterized by elemental analysis, complexometric titration, thermal analysis, conductivity, IR and ^1H- NMR. The results reveal that carboxyl group of the hgand coordinates with rare earth ions in bidentate mode after deprotonated. The water molecules exist as crystal water in the complexes. The anti-tumour activities of HL and some complexes were tested by both the MTT and SRB methods. The results show that the suppression ratios of some complexes against the tested tumour cells （HL-60 human leukemia cell lines, BGC-823 human gastric carcinoma cell lines, hela human cervix adenocarcinoma cell lines and Bel-7402 human hepatic carcinoma cell lines） are superior to HL.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
The title compound, [Cu2（DMPz）2PMo12O40]·HDMPz （1, DMPz = 2,5-dimethyl pyrazine）, has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group...The title compound, [Cu2（DMPz）2PMo12O40]·HDMPz （1, DMPz = 2,5-dimethyl pyrazine）, has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P1 with a = 11.075（2）, b = 11.551（2）, c = 11.886（2） A.α = 106.352（2）, β = 109.862（3）, γ = 109.504（1）°, V = 1206.8（3） A3, C18H26CU2Mo12N6O40P, Mr = 2275.78, Z = 1, Dc = 3.131 g/cm3, μ = 4.011 mm^-1, F（000） = 1073, S = 1.066, the final R = 0.0389 and wR = 0.1056 for 3739 observed reflections with I 〉 2σ（I）. The structural analysis indicates that the title compound is composed of Keggin clusters [PMo12O40]3- connected by one-dimensional [CB（DMPz）]2n^2n＋ chains to form a two-dimensional grid layer with holes occupied by monoprotonated DMPz molecules. In the solid of the title compound, the 2D grid layers are stacked together in an ABAB packing mode.展开更多
By the study of absorption and fluorescence spectra and the lifetime of fluorescence at room and low temperatures of 2,6-dimethyl naphthalene dicarboxylate (DMN) in different concentrations of sulfuric acid, different...By the study of absorption and fluorescence spectra and the lifetime of fluorescence at room and low temperatures of 2,6-dimethyl naphthalene dicarboxylate (DMN) in different concentrations of sulfuric acid, different interactions between molecules of DMN and sulfuric acid have been observed. These interactions have been revealed by the absorption spectra of charge transfer complex in the ground state, emission of exciplex, absorption spectra of hydrogen bonding interaction, absorption and emission spectra after proton transfer and different lifetimes before and after protonation. The interaction mechanism of DMN and sulfuric acid through first the CT complex and exciplex then hydrogen bonding and finally proton transfer is proposed.展开更多
Two new phloroglucinol glycosides, 2,6-dihydroxy-3,5-dimethyl-1-isobutyrylbenzene-4-O-beta-D-glucoside and 2,6-dihydroxy-3,5-dimethyl-1-(2-methylbutyryl) benzene-4-O-beta-D-glucoside were isolated from Hypericum japon...Two new phloroglucinol glycosides, 2,6-dihydroxy-3,5-dimethyl-1-isobutyrylbenzene-4-O-beta-D-glucoside and 2,6-dihydroxy-3,5-dimethyl-1-(2-methylbutyryl) benzene-4-O-beta-D-glucoside were isolated from Hypericum japonicum. Their structures were determined by spectroscopic and chemical methods.展开更多
The ab initio molecular orbital study on the mechanism of enantioselective reduction of 3,3-dimethyl butanone-2 with borane catalyzed by chiral oxazaborolidine is performed. As illustrated, this enantioselective reduc...The ab initio molecular orbital study on the mechanism of enantioselective reduction of 3,3-dimethyl butanone-2 with borane catalyzed by chiral oxazaborolidine is performed. As illustrated, this enantioselective reduction is exothermic and goes mainly through the formations of the catalyst-borane adduct, the catalyst-borane-3,3-dimethyl butanone-2 adduct, and the cata-lyst-alkoxyborane adduct with a B-O-B-N 4-member ring and through the decomposition of the catalyst-alkoxyborane adduct with the regeneration of the catalyst. During the hydride transfer in the catalyst-borane-3,3-dimethyl butanone-2 adduct to form the catalyst-alkoxyborane adduct, the hydride transfer and the formation of the B-O-B-N 4-member ring in the catalyst-alkoxyborane adduct happen simultaneously. The controlling step for the reduction is the transfer of hydride from the borane moiety to the carbonyl carbon of 3,3-dimethyl butanone-2. The transition state for the hydride transfer is a twisted chair structure and the reduction leads展开更多
文摘The effect of 2-butyne-1, 4-diol on silver electrodeposition process from 5, 5-dimethyl hydantoin solutions was investigated by means of cyclic voltammetric measurement, scanning electron microscopy (SEM) and X-ray diffraction (XRD). Cyclic voltammetric studies indicate that the reduction process of silver electrodeposition is influenced by adding 2-butyne-1, 4-diol. Owing to its adsorption on the electrode surface, 2-butyne-1, 4-diol moderately hinders the mass transfer of the silver complexed ions from the bulk solution to the outer limit of the electrode double layer and affects the electrocrystallization step. Scanning electron microscopy analysis reveals that the presence of 2-butyne-1, 4-diol in the electrolyte is beneficial and the silver deposits obtained are smoother, more compact and more leveled. X-ray diffraction analysis of the silver deposits obtained at 0.5 g·L-1 2-butyne-1, 4-diol indicated that the (110) plane is the most preferred plane and is not affected by the presence of 2-butyne-1, 4-diol in the electrolyte.
文摘Eight rare earth metal （ Ⅲ ） complexes with 2- （ （（4,6-dimethyl）-2-pyrimidinyl） thio）-acetic acid, LnL3· n H2O [HL = 2-（（（4,6-dimethyl）-2-pyrimidinyl）thio）-acetic acid; Ln = La, Ce, Pr, Nd, Sm Eu, Gd, Tb; n = 4 or 5], were prepared and characterized by elemental analysis, complexometric titration, thermal analysis, conductivity, IR and ^1H- NMR. The results reveal that carboxyl group of the hgand coordinates with rare earth ions in bidentate mode after deprotonated. The water molecules exist as crystal water in the complexes. The anti-tumour activities of HL and some complexes were tested by both the MTT and SRB methods. The results show that the suppression ratios of some complexes against the tested tumour cells （HL-60 human leukemia cell lines, BGC-823 human gastric carcinoma cell lines, hela human cervix adenocarcinoma cell lines and Bel-7402 human hepatic carcinoma cell lines） are superior to HL.
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.
基金supported by the Natural Science Foundation of Fujian Province (2006F3135,2006F3141,2007HZ0001-1)the Fund of Fujian Key Laboratory of Nanomaterials (2006L2005)
文摘The title compound, [Cu2（DMPz）2PMo12O40]·HDMPz （1, DMPz = 2,5-dimethyl pyrazine）, has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P1 with a = 11.075（2）, b = 11.551（2）, c = 11.886（2） A.α = 106.352（2）, β = 109.862（3）, γ = 109.504（1）°, V = 1206.8（3） A3, C18H26CU2Mo12N6O40P, Mr = 2275.78, Z = 1, Dc = 3.131 g/cm3, μ = 4.011 mm^-1, F（000） = 1073, S = 1.066, the final R = 0.0389 and wR = 0.1056 for 3739 observed reflections with I 〉 2σ（I）. The structural analysis indicates that the title compound is composed of Keggin clusters [PMo12O40]3- connected by one-dimensional [CB（DMPz）]2n^2n＋ chains to form a two-dimensional grid layer with holes occupied by monoprotonated DMPz molecules. In the solid of the title compound, the 2D grid layers are stacked together in an ABAB packing mode.
基金Proiect supported by the National Natural Science Foundation of China.
文摘By the study of absorption and fluorescence spectra and the lifetime of fluorescence at room and low temperatures of 2,6-dimethyl naphthalene dicarboxylate (DMN) in different concentrations of sulfuric acid, different interactions between molecules of DMN and sulfuric acid have been observed. These interactions have been revealed by the absorption spectra of charge transfer complex in the ground state, emission of exciplex, absorption spectra of hydrogen bonding interaction, absorption and emission spectra after proton transfer and different lifetimes before and after protonation. The interaction mechanism of DMN and sulfuric acid through first the CT complex and exciplex then hydrogen bonding and finally proton transfer is proposed.
文摘Two new phloroglucinol glycosides, 2,6-dihydroxy-3,5-dimethyl-1-isobutyrylbenzene-4-O-beta-D-glucoside and 2,6-dihydroxy-3,5-dimethyl-1-(2-methylbutyryl) benzene-4-O-beta-D-glucoside were isolated from Hypericum japonicum. Their structures were determined by spectroscopic and chemical methods.
基金the Key Project of Science and Technology of the Ministry of Education, China.
文摘The ab initio molecular orbital study on the mechanism of enantioselective reduction of 3,3-dimethyl butanone-2 with borane catalyzed by chiral oxazaborolidine is performed. As illustrated, this enantioselective reduction is exothermic and goes mainly through the formations of the catalyst-borane adduct, the catalyst-borane-3,3-dimethyl butanone-2 adduct, and the cata-lyst-alkoxyborane adduct with a B-O-B-N 4-member ring and through the decomposition of the catalyst-alkoxyborane adduct with the regeneration of the catalyst. During the hydride transfer in the catalyst-borane-3,3-dimethyl butanone-2 adduct to form the catalyst-alkoxyborane adduct, the hydride transfer and the formation of the B-O-B-N 4-member ring in the catalyst-alkoxyborane adduct happen simultaneously. The controlling step for the reduction is the transfer of hydride from the borane moiety to the carbonyl carbon of 3,3-dimethyl butanone-2. The transition state for the hydride transfer is a twisted chair structure and the reduction leads
