A novel binary photosensitization system composed of benzophenone (BP)/diphenyliodonium chloride (DPIOC) Ariethylamine (TEA), exhibiting a good photoresponse at near UV and visible light regions, was used as the initi...A novel binary photosensitization system composed of benzophenone (BP)/diphenyliodonium chloride (DPIOC) Ariethylamine (TEA), exhibiting a good photoresponse at near UV and visible light regions, was used as the initiator for photopolymerization of MMA. The radical photogeneration in the binary system consists mainly of two parallel reactions, i. e. , BP/TEA photohydrogen-abstraction and DPIOC/TEA complex photodecomposition, but the latter is more active than the former. The results of comparative study indicate that the rate of polymerization induced by the binary system (BDT)is remarkably higher than those by the corresponding single systems The polymerization rates are proportional to [BP]^(0.16), [DPIOC]^(0.32) [TEA]^(0.45) and [MMA]. The mechanism is also discussed.展开更多
The diphenyliodonium salt (DPIOC)/triethylamine (TEA) is used as photoinitiator for radical photopolymerization. It was found that a ground state CT complex formed between DPIOC as electron acceptor and TEA as electro...The diphenyliodonium salt (DPIOC)/triethylamine (TEA) is used as photoinitiator for radical photopolymerization. It was found that a ground state CT complex formed between DPIOC as electron acceptor and TEA as electron donor, which results in extending the photosensitivity range of DPIOC/TEA system up to above 500nm compared with DPIOC alone. The kinetic studies on photopolymerization of methyl methacrylate (MMA) were carried out in CH_3CN: H_2O (14: 1, v/v) mixture solution at 30℃ by dilatometer. The results obtained show that the polymerization rate (R_p) increases with increasing concentrations of DPIOC and TEA with exponent 0. 65 and 0. 62 respectively. The activation energy E_a and k_p/k_^(1/2) value were determined to be 4.1 Kcal mol^(-1) and 0.045 respectively. The other influence factors and reaction mechanism were also discussed.展开更多
Task specific onium salt has been presented as soluble support in the synthesis of benzopyrans in this paper. This method allows for results by far superior to those reported other soluble supports and allows for very...Task specific onium salt has been presented as soluble support in the synthesis of benzopyrans in this paper. This method allows for results by far superior to those reported other soluble supports and allows for very easy purifications of reaction products.展开更多
The present paper contains the effects of the ammonium ion, counter ion, solvent and anion being transferred on the solid-liquid phase transfer equilibrium constant of quaternary ammonium salts. The most striking diff...The present paper contains the effects of the ammonium ion, counter ion, solvent and anion being transferred on the solid-liquid phase transfer equilibrium constant of quaternary ammonium salts. The most striking difference between solid-liquid and liquid-liquid phase transfer equilibriums is that the length of alkyl chain shows a large effect on the latter but little on the former This means that the chain length affects only the hydrophobicity, rather than the lipophilicity.Keywords Quaternary ammonium salt, Phase transfer catalysis, Equilibrium constant, Hydrophobicity, Lipophilicity展开更多
In this work it was presented an application of task specific onium salt as soluble support for the synthesis of 3-amino-5-aryl-2,5- dihydropyridazines. This soluble support is of wide applicability and combines advan...In this work it was presented an application of task specific onium salt as soluble support for the synthesis of 3-amino-5-aryl-2,5- dihydropyridazines. This soluble support is of wide applicability and combines advantages of solid phase synthesis without its limitations with those of solution phase chemistry. After a simple washing step, products were cleaved from the supports and obtained in good yields.展开更多
文摘A novel binary photosensitization system composed of benzophenone (BP)/diphenyliodonium chloride (DPIOC) Ariethylamine (TEA), exhibiting a good photoresponse at near UV and visible light regions, was used as the initiator for photopolymerization of MMA. The radical photogeneration in the binary system consists mainly of two parallel reactions, i. e. , BP/TEA photohydrogen-abstraction and DPIOC/TEA complex photodecomposition, but the latter is more active than the former. The results of comparative study indicate that the rate of polymerization induced by the binary system (BDT)is remarkably higher than those by the corresponding single systems The polymerization rates are proportional to [BP]^(0.16), [DPIOC]^(0.32) [TEA]^(0.45) and [MMA]. The mechanism is also discussed.
文摘The diphenyliodonium salt (DPIOC)/triethylamine (TEA) is used as photoinitiator for radical photopolymerization. It was found that a ground state CT complex formed between DPIOC as electron acceptor and TEA as electron donor, which results in extending the photosensitivity range of DPIOC/TEA system up to above 500nm compared with DPIOC alone. The kinetic studies on photopolymerization of methyl methacrylate (MMA) were carried out in CH_3CN: H_2O (14: 1, v/v) mixture solution at 30℃ by dilatometer. The results obtained show that the polymerization rate (R_p) increases with increasing concentrations of DPIOC and TEA with exponent 0. 65 and 0. 62 respectively. The activation energy E_a and k_p/k_^(1/2) value were determined to be 4.1 Kcal mol^(-1) and 0.045 respectively. The other influence factors and reaction mechanism were also discussed.
基金Supported by the National Natural Sciences Foundation of China(No.20772026)the 2007 Excellent Mid-youth Innovative Team Project of the Education Department of Hubei Province, China(No.T200701)
文摘Task specific onium salt has been presented as soluble support in the synthesis of benzopyrans in this paper. This method allows for results by far superior to those reported other soluble supports and allows for very easy purifications of reaction products.
文摘The present paper contains the effects of the ammonium ion, counter ion, solvent and anion being transferred on the solid-liquid phase transfer equilibrium constant of quaternary ammonium salts. The most striking difference between solid-liquid and liquid-liquid phase transfer equilibriums is that the length of alkyl chain shows a large effect on the latter but little on the former This means that the chain length affects only the hydrophobicity, rather than the lipophilicity.Keywords Quaternary ammonium salt, Phase transfer catalysis, Equilibrium constant, Hydrophobicity, Lipophilicity
基金the Natural Sciences Foundation of Hubei province in China(Nos.2007ABA031 and 2008CDA078)
文摘In this work it was presented an application of task specific onium salt as soluble support for the synthesis of 3-amino-5-aryl-2,5- dihydropyridazines. This soluble support is of wide applicability and combines advantages of solid phase synthesis without its limitations with those of solution phase chemistry. After a simple washing step, products were cleaved from the supports and obtained in good yields.
