The kinetic model for diffusion-controlled intermolecular reaction of homogenous polymer under steady shear was theoretically studied. The classic formalism and the concept of conformation ellipsoids were integrated t...The kinetic model for diffusion-controlled intermolecular reaction of homogenous polymer under steady shear was theoretically studied. The classic formalism and the concept of conformation ellipsoids were integrated to get a new equation, which directly correlates the rate constant with shear rate. It was found that the rate constant is not monotonic with shear rate. The scale of rate constant is N^-1.5 (N is the length of chains), which is in consistent with de Gennes's result.展开更多
Intermolecular Stetter reaction of aromatic aldehydes with(E)-(2-nitrovinyl)cyclohexane catalyzed by thiazolium A has been developed.The reaction rate and efficiency are profoundly impacted by the presence of thio...Intermolecular Stetter reaction of aromatic aldehydes with(E)-(2-nitrovinyl)cyclohexane catalyzed by thiazolium A has been developed.The reaction rate and efficiency are profoundly impacted by the presence of thiourea B.The reaction affords moderate to good yields of the Stetter product.Some factors influencing yield were discussed.展开更多
The reaction mechanisms of intermolecular cleavage reaction of N-(2-hydroxyphenyl)-phthalamic acid were studied via the density functional theory(DFT). All geometries of the reactant, transition states, and produc...The reaction mechanisms of intermolecular cleavage reaction of N-(2-hydroxyphenyl)-phthalamic acid were studied via the density functional theory(DFT). All geometries of the reactant, transition states, and products were optimized at the B3LYP/6-31G(d, p) level. Vibration analysis was carried out to confirm its identity as transitions' structure, and the intrinsic reaction coordinate method(IRC) was used to search the minimum energy path. Two possible reaction channels are reported in this article. The calculated results indicate that O-cyclization reaction channel has the lower activation barrier, and therefore, it occurs more easier than the other.展开更多
The miscibility of the blend,composed of a bisphenol A epoxy resins (Diglycidyl ether of bisphenol A) (DGEBA) and poly(ethylene oxide) (PEG) and crosslinked by phthalic anhydride (PA) was studied using dynamic mechani...The miscibility of the blend,composed of a bisphenol A epoxy resins (Diglycidyl ether of bisphenol A) (DGEBA) and poly(ethylene oxide) (PEG) and crosslinked by phthalic anhydride (PA) was studied using dynamic mechanical method. Single glass transition temperatures intermediate between the two pure components were observed for all blend levels. The secondary relaxation mechanism should relate to not only diester linkage, but also hydroxyether structural unit in the system. Fourier transform infrared spectroscopy (FTIR) is applied to study the curing reaction and intermolecular specific interaction of the system. The results indicate the PEO participates the crosslinking reaction, accelerates the curing reaction and make the reaction more perfect. The shifts of the hydroxyl band and carbonyl band demonstrate the presence of the intermolecular interaction in the cured blend. Moreover, the molecular interaction between the side hydroxyl in the hydroxyether units and the ether bond in PEO macromolecules is stronger.展开更多
A series of symmetrical biaryls was synthesized from arylmercuric chlorides and biarylmercurials in the presence of [ClRh(CO) 2] 2 in hexamethylphosphoramide(HMPA). The mechanism of the [ClRh(CO) 2] 2 catalyzed d...A series of symmetrical biaryls was synthesized from arylmercuric chlorides and biarylmercurials in the presence of [ClRh(CO) 2] 2 in hexamethylphosphoramide(HMPA). The mechanism of the [ClRh(CO) 2] 2 catalyzed dimerization of biarylmercurials was studied, and shown to be mainly intermolecular reaction.展开更多
基金This work was financially supported by the National Natural Science Foundation of China (No. 50390090).
文摘The kinetic model for diffusion-controlled intermolecular reaction of homogenous polymer under steady shear was theoretically studied. The classic formalism and the concept of conformation ellipsoids were integrated to get a new equation, which directly correlates the rate constant with shear rate. It was found that the rate constant is not monotonic with shear rate. The scale of rate constant is N^-1.5 (N is the length of chains), which is in consistent with de Gennes's result.
基金supported by the Prospective Research Funds of Jiangsu Provincial Department of Science and Technology (No. BY2015049-02)the Open-end Funds of Jiangsu Key Laboratory of Marine Biotechnology, Huaihai Institute of Technology, (No. 2014HS005)the Funds of Technology Research of Lianyungang (No. CG1301)
文摘Intermolecular Stetter reaction of aromatic aldehydes with(E)-(2-nitrovinyl)cyclohexane catalyzed by thiazolium A has been developed.The reaction rate and efficiency are profoundly impacted by the presence of thiourea B.The reaction affords moderate to good yields of the Stetter product.Some factors influencing yield were discussed.
基金Supported by the National Natural Science Foundation of China(No.20672104)
文摘The reaction mechanisms of intermolecular cleavage reaction of N-(2-hydroxyphenyl)-phthalamic acid were studied via the density functional theory(DFT). All geometries of the reactant, transition states, and products were optimized at the B3LYP/6-31G(d, p) level. Vibration analysis was carried out to confirm its identity as transitions' structure, and the intrinsic reaction coordinate method(IRC) was used to search the minimum energy path. Two possible reaction channels are reported in this article. The calculated results indicate that O-cyclization reaction channel has the lower activation barrier, and therefore, it occurs more easier than the other.
基金This study is partially supported by the National Natural Science Foundation of China.
文摘The miscibility of the blend,composed of a bisphenol A epoxy resins (Diglycidyl ether of bisphenol A) (DGEBA) and poly(ethylene oxide) (PEG) and crosslinked by phthalic anhydride (PA) was studied using dynamic mechanical method. Single glass transition temperatures intermediate between the two pure components were observed for all blend levels. The secondary relaxation mechanism should relate to not only diester linkage, but also hydroxyether structural unit in the system. Fourier transform infrared spectroscopy (FTIR) is applied to study the curing reaction and intermolecular specific interaction of the system. The results indicate the PEO participates the crosslinking reaction, accelerates the curing reaction and make the reaction more perfect. The shifts of the hydroxyl band and carbonyl band demonstrate the presence of the intermolecular interaction in the cured blend. Moreover, the molecular interaction between the side hydroxyl in the hydroxyether units and the ether bond in PEO macromolecules is stronger.
基金Supported by the Scientific Research Foundation for Returned Overseas Chinese Scholarsof Educational Ministry ofChina
文摘A series of symmetrical biaryls was synthesized from arylmercuric chlorides and biarylmercurials in the presence of [ClRh(CO) 2] 2 in hexamethylphosphoramide(HMPA). The mechanism of the [ClRh(CO) 2] 2 catalyzed dimerization of biarylmercurials was studied, and shown to be mainly intermolecular reaction.