Atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) employing ethyl 2-bromoisobutyrate (EBiB)/ CuBr as the initiating system was investigated at 50 ℃ in the absence of any additional ligand...Atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) employing ethyl 2-bromoisobutyrate (EBiB)/ CuBr as the initiating system was investigated at 50 ℃ in the absence of any additional ligand in the three room temperature ionic liquids (RTILs), 1-methyl-imidazolium acetate ([mim][CH3COO]), 1-methylimidazolium propionate ([mim][CH3CH2COO]) and 1-methylimidazolium butyrate ([mim][CH3CH2CH2COO]), respectively. All the polymerization in the three RTILs proceeded in a well-controlled manner. The sequence of the apparent polymerization rate constants was kapp([mim][CH3COO]) 〉 kapp([mim] [CH3CH2COO]) 〉 kapp ([mim][CH3CH2CH2COO]).展开更多
The structures of four isomeric forms of the model germylenoid, H2GeLiF. have been examined by ah initio MO theory. The most stable structure is suggested to be the p-complex 1.The other three species. three-membered ...The structures of four isomeric forms of the model germylenoid, H2GeLiF. have been examined by ah initio MO theory. The most stable structure is suggested to be the p-complex 1.The other three species. three-membered ring 2, δ-complex 3 and tetrahedron 4. are also local minima on the potential energy surface. but are higher in energy.展开更多
基金Financial support from Zhejiang Provincial Natural Science Foundation (No.R203154, Y405124) is gratefully acknowledged.
文摘Atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) employing ethyl 2-bromoisobutyrate (EBiB)/ CuBr as the initiating system was investigated at 50 ℃ in the absence of any additional ligand in the three room temperature ionic liquids (RTILs), 1-methyl-imidazolium acetate ([mim][CH3COO]), 1-methylimidazolium propionate ([mim][CH3CH2COO]) and 1-methylimidazolium butyrate ([mim][CH3CH2CH2COO]), respectively. All the polymerization in the three RTILs proceeded in a well-controlled manner. The sequence of the apparent polymerization rate constants was kapp([mim][CH3COO]) 〉 kapp([mim] [CH3CH2COO]) 〉 kapp ([mim][CH3CH2CH2COO]).
文摘The structures of four isomeric forms of the model germylenoid, H2GeLiF. have been examined by ah initio MO theory. The most stable structure is suggested to be the p-complex 1.The other three species. three-membered ring 2, δ-complex 3 and tetrahedron 4. are also local minima on the potential energy surface. but are higher in energy.