The driving force for inclusion complexation of α and β CD with substituted benzene(PhX) was studied by means of step wise regression analysis. A set of multiple regression equations was established with...The driving force for inclusion complexation of α and β CD with substituted benzene(PhX) was studied by means of step wise regression analysis. A set of multiple regression equations was established with correlation coefficients 0 96 and 0 94 for the individual complexation of α CD and β CD with PhX. The ln K a(calc.) values calculated with the aid of the regression equations were close to those determined experimentally. The inclusion complexation is dominantly driven by van der Waals force and hydrophobic interactions.展开更多
Using a novel freshwater photobacteria — Q67 as an indication organism and the VeritasTM luminometer with 96-well microplate as the testing equipment to determine luminous intensity of photobacteria,the familiar 29 s...Using a novel freshwater photobacteria — Q67 as an indication organism and the VeritasTM luminometer with 96-well microplate as the testing equipment to determine luminous intensity of photobacteria,the familiar 29 substituted benzenes of the median inhibition toxicities（pEC50）were determined,respectively.The quantum chemical parameters of 29 substituted benzenes in the ideal gas state at 298.15 K and 1.013×105 Pa have been calculated at the B3LYP/6-31G＊ level using Gaussian 03 program.The Quantitative linear relationship（N1）between the pEC50 and two descriptors of 29 substituted benzenes was developed using the variable selection and modeling based on prediction（VSMP）.Model N1 showed good estimation ability and stability（r = 0.8777,q = 0.8482）,which exhibited the difference between empirical and predicted values of 2,3-dimethylphenol was greater（0.5）,so it was given up.Using VSMP to select the optimal descriptors,a 2-variable multiple linear regression model（called model N2）was developed for the pEC50 of substituted benzenes.The r and q for model N2 based on 28 substituted benzenes are 0.8991 and 0.8735,respectively.In order to validate the model,28 substituted benzenes were divided into a training set consisting of 20 compounds and a test set with 8 compounds.The result showed that some main structural factors influencing the pEC50 of substituted benzenes are the lowest unoccupied orbital（ELUMO）and total energy（EHF）.展开更多
Ligand exchange reaction is one of the typical reactions of ferrocene. In this paper, ligand exchange reactions were carried out between ferrocene and various substituted benzenes using aluminum chloride catalysis. Th...Ligand exchange reaction is one of the typical reactions of ferrocene. In this paper, ligand exchange reactions were carried out between ferrocene and various substituted benzenes using aluminum chloride catalysis. The product yields of the reactions with alkanoyl- and alkoxybenzenes were low because of the coordination of aluminum chloride to the oxygens of the benzene substituents. Comparing the reactions using o- and p-dimethoxybenzene, the former was revealed to be less reactive;this is likely due to the deviation of the π-electrons of its benzene ring being larger.展开更多
3-Methylthio-5-hydroxy-1,2,4-triazine(1c)reacted with substituted benzenesulfonyl chloride to give 3-methylthio-5-oxy-1,2,4-triazin-6-yl pyridinium betaine(4)in anhydrous pyridine.But when NaOH/H_2O/CH_3COCH_3 or NaOH...3-Methylthio-5-hydroxy-1,2,4-triazine(1c)reacted with substituted benzenesulfonyl chloride to give 3-methylthio-5-oxy-1,2,4-triazin-6-yl pyridinium betaine(4)in anhydrous pyridine.But when NaOH/H_2O/CH_3COCH_3 or NaOH/CH_3OH were used as reactant and solvent,3-methylthio-4-substituted benzenesulfonyl-5-oxo-6-hydroxy-1,4,5,6-tetrahydro-1,2,4-triazine(6)or 1-tosyl-3-methylthio-5-oxo-6-methyloxy-1,4,5,6-tetrahydro-1,2,4-triazine(7)was obtained respectively.The above reactions show anomalous properties of nucleophilic attack on 6-carbon in 1,2,4-triazine ring.展开更多
Ionizations and fragmentations of benzene, methylbenzene, and chlorobenzene are studied in linearly polarized 50-fs, 800-nm and 400-nm strong laser fields using a time-of-flight mass spectrometer. It is shown that at ...Ionizations and fragmentations of benzene, methylbenzene, and chlorobenzene are studied in linearly polarized 50-fs, 800-nm and 400-nm strong laser fields using a time-of-flight mass spectrometer. It is shown that at low laser intensity, the parent ions are dominant for any one of the molecules in an 800-nm strong laser field, while extensive fragmentation is observed in a 400-nm laser field, which can be understood by the resonant photon absorption of molecular cations. The ratio of the yield of the parent ion to the yield of the total ion for each molecule is measured as a function of laser intensity in a range from 1.0 × 1013 W/cm2 to 4.0 × 1014 W/cm2, in either the 800-nm or 400-nm laser field. The results show that the fragmentation of the aromatic molecules increases significantly as the laser intensity is increased. Possible mechanisms for fragmentation in strong laser fields are discussed. Finally, the saturation intensity of ionization of the titled molecules is also determined.展开更多
Based on the formation of 2,5-bis（trimethylsilyl）-zirconacyclopentadienes from two silylalkynes with CpEZrBu2 and the Cu-mediated formation of 1,4-disilylbenzene via the cycloaddition of zirconacyclopentadienes to d...Based on the formation of 2,5-bis（trimethylsilyl）-zirconacyclopentadienes from two silylalkynes with CpEZrBu2 and the Cu-mediated formation of 1,4-disilylbenzene via the cycloaddition of zirconacyclopentadienes to disubstituted alkynes, a selective synthesis of 1,4-dialkyl（aryl）-hexa-substituted benzenes was achieved followed by iodination and coupling reaction. The coupling reactions were carried out with either organolithium reagent or orga- nozinc reagent（Negishi coupling）, depending on the electrophilic species.展开更多
Superacid ZrO_2:H_2SO_4 showed high activity in Friedel-Crafts benzoylation of benzene and substituted benzenes such an chlorobenzene,toluene and 1,3,5-trimethylbenzene.Benzophenones in 90-100% yields were obtained wi...Superacid ZrO_2:H_2SO_4 showed high activity in Friedel-Crafts benzoylation of benzene and substituted benzenes such an chlorobenzene,toluene and 1,3,5-trimethylbenzene.Benzophenones in 90-100% yields were obtained with catalytic amount of superacid ZrO_2:H_2SO_4.The calcination temperature greatly influenced the acid strength and activity of the superacid ZrO_2:H_2SO_4.The superacid has both Lewis and Bronsted acid sites.The reversibility of Friedel-Crafts benzoylation and transacylation were observed over the superacid.The used superacid could be readily regenerated and showed identical benzoylation activity to toluene.展开更多
文摘The driving force for inclusion complexation of α and β CD with substituted benzene(PhX) was studied by means of step wise regression analysis. A set of multiple regression equations was established with correlation coefficients 0 96 and 0 94 for the individual complexation of α CD and β CD with PhX. The ln K a(calc.) values calculated with the aid of the regression equations were close to those determined experimentally. The inclusion complexation is dominantly driven by van der Waals force and hydrophobic interactions.
基金Sponsored by the Water Pollution Control and Management of Major Special Technology (2008ZX07317-02-03E)the Ministry of Education of Guangxi Zhuang Autonomous Region (200911MS108)Guangxi Key Laboratory of Environmental Engineering,Protection and Assessment (Nos.0801Z026,0801Z027)
文摘Using a novel freshwater photobacteria — Q67 as an indication organism and the VeritasTM luminometer with 96-well microplate as the testing equipment to determine luminous intensity of photobacteria,the familiar 29 substituted benzenes of the median inhibition toxicities（pEC50）were determined,respectively.The quantum chemical parameters of 29 substituted benzenes in the ideal gas state at 298.15 K and 1.013×105 Pa have been calculated at the B3LYP/6-31G＊ level using Gaussian 03 program.The Quantitative linear relationship（N1）between the pEC50 and two descriptors of 29 substituted benzenes was developed using the variable selection and modeling based on prediction（VSMP）.Model N1 showed good estimation ability and stability（r = 0.8777,q = 0.8482）,which exhibited the difference between empirical and predicted values of 2,3-dimethylphenol was greater（0.5）,so it was given up.Using VSMP to select the optimal descriptors,a 2-variable multiple linear regression model（called model N2）was developed for the pEC50 of substituted benzenes.The r and q for model N2 based on 28 substituted benzenes are 0.8991 and 0.8735,respectively.In order to validate the model,28 substituted benzenes were divided into a training set consisting of 20 compounds and a test set with 8 compounds.The result showed that some main structural factors influencing the pEC50 of substituted benzenes are the lowest unoccupied orbital（ELUMO）and total energy（EHF）.
文摘Ligand exchange reaction is one of the typical reactions of ferrocene. In this paper, ligand exchange reactions were carried out between ferrocene and various substituted benzenes using aluminum chloride catalysis. The product yields of the reactions with alkanoyl- and alkoxybenzenes were low because of the coordination of aluminum chloride to the oxygens of the benzene substituents. Comparing the reactions using o- and p-dimethoxybenzene, the former was revealed to be less reactive;this is likely due to the deviation of the π-electrons of its benzene ring being larger.
基金Director of the project supported by National Natural Science foundation of China.
文摘3-Methylthio-5-hydroxy-1,2,4-triazine(1c)reacted with substituted benzenesulfonyl chloride to give 3-methylthio-5-oxy-1,2,4-triazin-6-yl pyridinium betaine(4)in anhydrous pyridine.But when NaOH/H_2O/CH_3COCH_3 or NaOH/CH_3OH were used as reactant and solvent,3-methylthio-4-substituted benzenesulfonyl-5-oxo-6-hydroxy-1,4,5,6-tetrahydro-1,2,4-triazine(6)or 1-tosyl-3-methylthio-5-oxo-6-methyloxy-1,4,5,6-tetrahydro-1,2,4-triazine(7)was obtained respectively.The above reactions show anomalous properties of nucleophilic attack on 6-carbon in 1,2,4-triazine ring.
基金supported by the National Basic Research Program of China(Grant No.2013CB922200)the National Natural Science Foundation of China(Grant No.11274140)
文摘Ionizations and fragmentations of benzene, methylbenzene, and chlorobenzene are studied in linearly polarized 50-fs, 800-nm and 400-nm strong laser fields using a time-of-flight mass spectrometer. It is shown that at low laser intensity, the parent ions are dominant for any one of the molecules in an 800-nm strong laser field, while extensive fragmentation is observed in a 400-nm laser field, which can be understood by the resonant photon absorption of molecular cations. The ratio of the yield of the parent ion to the yield of the total ion for each molecule is measured as a function of laser intensity in a range from 1.0 × 1013 W/cm2 to 4.0 × 1014 W/cm2, in either the 800-nm or 400-nm laser field. The results show that the fragmentation of the aromatic molecules increases significantly as the laser intensity is increased. Possible mechanisms for fragmentation in strong laser fields are discussed. Finally, the saturation intensity of ionization of the titled molecules is also determined.
基金Supported by the National Natural Science Foundation of China（No.21102099）.
文摘Based on the formation of 2,5-bis（trimethylsilyl）-zirconacyclopentadienes from two silylalkynes with CpEZrBu2 and the Cu-mediated formation of 1,4-disilylbenzene via the cycloaddition of zirconacyclopentadienes to disubstituted alkynes, a selective synthesis of 1,4-dialkyl（aryl）-hexa-substituted benzenes was achieved followed by iodination and coupling reaction. The coupling reactions were carried out with either organolithium reagent or orga- nozinc reagent（Negishi coupling）, depending on the electrophilic species.
文摘Superacid ZrO_2:H_2SO_4 showed high activity in Friedel-Crafts benzoylation of benzene and substituted benzenes such an chlorobenzene,toluene and 1,3,5-trimethylbenzene.Benzophenones in 90-100% yields were obtained with catalytic amount of superacid ZrO_2:H_2SO_4.The calcination temperature greatly influenced the acid strength and activity of the superacid ZrO_2:H_2SO_4.The superacid has both Lewis and Bronsted acid sites.The reversibility of Friedel-Crafts benzoylation and transacylation were observed over the superacid.The used superacid could be readily regenerated and showed identical benzoylation activity to toluene.
