以聚乙二醇400(PEG-400)作溶剂,通过CuSO4/KI催化的邻氨基吡啶与苯乙酮的串联式缩合-环化-芳构化反应,发展出一种高效且环境友好型的合成2-苯基咪唑并[1,2-a]吡啶的方法.该方法具有操作简单、使用无毒性PEG-400作反应介质、催化剂安全...以聚乙二醇400(PEG-400)作溶剂,通过CuSO4/KI催化的邻氨基吡啶与苯乙酮的串联式缩合-环化-芳构化反应,发展出一种高效且环境友好型的合成2-苯基咪唑并[1,2-a]吡啶的方法.该方法具有操作简单、使用无毒性PEG-400作反应介质、催化剂安全价廉等优点.所有产物结构经1 H NMR及13 C NMR进行了确认.展开更多
The structural, electronic, and magnetic properties of ConO （n = 2- 10） clusters have been systematically investigated within the framework of the generalized gradient approximation density functional theory. The re...The structural, electronic, and magnetic properties of ConO （n = 2- 10） clusters have been systematically investigated within the framework of the generalized gradient approximation density functional theory. The results indicate that the O atom occupies the surface-capped position on ConO （n = 2-10） clusters. The stabilities of the host clusters are improved by adding one O atom. Maximum peaks of the second-order difference energy of the ground-state ConO clusters are found at n = 3, 6 and 8, indicating higher stability than their neighboring clusters. Compared with corresponding pure Con clusters, the O-doped cobalt clusters have larger gaps between the HOMO and LUMO energy levels, indicating their higher chemical stabilities. In addition, the doping of O atom exhibits different influence on the magnetism of the clusters. This is also further investigated by the local magnetic moment, deformation charge density and partial local density of states analysis.展开更多
The configurations,stabilities,electronic,and magnetic properties of FenAu（n = 1–12） clusters are investigated systematically by using the relativistic all-electron density functional theory with the generalized gr...The configurations,stabilities,electronic,and magnetic properties of FenAu（n = 1–12） clusters are investigated systematically by using the relativistic all-electron density functional theory with the generalized gradient approximation.The substitutional effects of Au in Fen＋1（n = 1,2,4,5,10–12） clusters are found in optimized structures which keep the similar frameworks with the most stable Fen＋1clusters.And the growth way for FenAu（n = 6–9） clusters is that the Au atom occupies a peripheral position of Fen cluster.The peaks appear respectively at n = 6 and 9 for Fen Au clusters and at n = 5 and 10 for Fen＋1clusters based on the size dependence of second-order difference of energy,implying that these clusters possess relatively high stabilities.The analysis of atomic net charge Q indicates that the charge always transfers from Fe to Au atom which causes the Au atom to be nearly non-magnetic,and the doped Au atom has little effect on the average magnetic moment of Fe atoms in Fen Au cluster.Finally,the total magnetic moment is reduced by 3 μB for each of Fen Au clusters except n = 3,11,and 12 compared with for corresponding pure Fen＋1 clusters.展开更多
文摘以聚乙二醇400(PEG-400)作溶剂,通过CuSO4/KI催化的邻氨基吡啶与苯乙酮的串联式缩合-环化-芳构化反应,发展出一种高效且环境友好型的合成2-苯基咪唑并[1,2-a]吡啶的方法.该方法具有操作简单、使用无毒性PEG-400作反应介质、催化剂安全价廉等优点.所有产物结构经1 H NMR及13 C NMR进行了确认.
基金supported by the National Natural Science Foundation of China(No.21301112)the Ph.D.Program Foundation of Ministry of China(No.20131404120001)
文摘The structural, electronic, and magnetic properties of ConO （n = 2- 10） clusters have been systematically investigated within the framework of the generalized gradient approximation density functional theory. The results indicate that the O atom occupies the surface-capped position on ConO （n = 2-10） clusters. The stabilities of the host clusters are improved by adding one O atom. Maximum peaks of the second-order difference energy of the ground-state ConO clusters are found at n = 3, 6 and 8, indicating higher stability than their neighboring clusters. Compared with corresponding pure Con clusters, the O-doped cobalt clusters have larger gaps between the HOMO and LUMO energy levels, indicating their higher chemical stabilities. In addition, the doping of O atom exhibits different influence on the magnetism of the clusters. This is also further investigated by the local magnetic moment, deformation charge density and partial local density of states analysis.
基金Project supported by the National Natural Science Foundation of China(Grant No.21301112)the Ph.D.Program Foundation of the Education Ministry of China(Grant No.20131404120001)
文摘The configurations,stabilities,electronic,and magnetic properties of FenAu（n = 1–12） clusters are investigated systematically by using the relativistic all-electron density functional theory with the generalized gradient approximation.The substitutional effects of Au in Fen＋1（n = 1,2,4,5,10–12） clusters are found in optimized structures which keep the similar frameworks with the most stable Fen＋1clusters.And the growth way for FenAu（n = 6–9） clusters is that the Au atom occupies a peripheral position of Fen cluster.The peaks appear respectively at n = 6 and 9 for Fen Au clusters and at n = 5 and 10 for Fen＋1clusters based on the size dependence of second-order difference of energy,implying that these clusters possess relatively high stabilities.The analysis of atomic net charge Q indicates that the charge always transfers from Fe to Au atom which causes the Au atom to be nearly non-magnetic,and the doped Au atom has little effect on the average magnetic moment of Fe atoms in Fen Au cluster.Finally,the total magnetic moment is reduced by 3 μB for each of Fen Au clusters except n = 3,11,and 12 compared with for corresponding pure Fen＋1 clusters.
