Herein,copper-catalyzed 1,4-protosilylation and 1,4-protoborylation of enynic orthoesters have been developed.The enynic orthoesters as precursors of unstable enynic esters were applied to produce the functionalized 2...Herein,copper-catalyzed 1,4-protosilylation and 1,4-protoborylation of enynic orthoesters have been developed.The enynic orthoesters as precursors of unstable enynic esters were applied to produce the functionalized 2,3-allenoate products.Meanwhile,the asymmetric 1,4-protosilylation of enynic orthoesters with Ph Me2Si-Bpin was also studied.The chiral monopyridine imidazoline ligand was efficient to provide the asymmetric 1,4-protosilylation products with high enantioselectivity.展开更多
采用Co_(3)O_(4)吸附脱除模拟柴油中的喹啉、吡啶或苯胺,考察了最佳吸附温度、吸附时间等条件,同时进行了吸附热力学和动力学研究;基于第一性原理对Co_(3)O_(4)晶胞进行相分析,对3种氮化物进行最高占据分子轨道(HOMO)-最低未占据分子轨...采用Co_(3)O_(4)吸附脱除模拟柴油中的喹啉、吡啶或苯胺,考察了最佳吸附温度、吸附时间等条件,同时进行了吸附热力学和动力学研究;基于第一性原理对Co_(3)O_(4)晶胞进行相分析,对3种氮化物进行最高占据分子轨道(HOMO)-最低未占据分子轨道(LUMO)分析,计算了吸附构型的吸附能和最稳定吸附构型的Mulliken电荷转移与电子密度。结果表明:在15 mL模拟柴油中加入0.6 g Co_(3)O_(4),苯胺、吡啶、喹啉的最佳吸附温度分别为20、20和30℃,最佳吸附时间分别为30、30、40 min,吸附容量由大到小顺序均为苯胺>吡啶>喹啉。热力学与动力学分析表明,喹啉、吡啶、苯胺的吸附均更符合多分子层吸附的Freundlich模型和准二级动力学方程。HOMO-LUMO分析结果表明,Co_(3)O_(4)为电子接受体,3种氮化物为电子给予体,Co_(3)O_(4)对喹啉、吡啶的配位吸附结构最稳定,对苯胺的π络合吸附最稳定。电荷转移计算表明,苯胺、吡啶、喹啉向Co_(3)O_(4)团簇转移的电荷数分别为0.423、0.394、0.368,说明Co_(3)O_(4)吸附3种氮化物的吸附能力大小为苯胺>吡啶>喹啉;电子密度图结果表明,最稳定吸附结构中Co_(3)O_(4)与3种氮化物均形成了化学键。展开更多
基金the funding support of the National Natural Science Foundation of China(No.21871240)the Strategic Priority Research Program of the CAS(No.XDPB14)the Fundamental Research Funds for the Central Universities(No.WK2060190082)。
文摘Herein,copper-catalyzed 1,4-protosilylation and 1,4-protoborylation of enynic orthoesters have been developed.The enynic orthoesters as precursors of unstable enynic esters were applied to produce the functionalized 2,3-allenoate products.Meanwhile,the asymmetric 1,4-protosilylation of enynic orthoesters with Ph Me2Si-Bpin was also studied.The chiral monopyridine imidazoline ligand was efficient to provide the asymmetric 1,4-protosilylation products with high enantioselectivity.
文摘采用Co_(3)O_(4)吸附脱除模拟柴油中的喹啉、吡啶或苯胺,考察了最佳吸附温度、吸附时间等条件,同时进行了吸附热力学和动力学研究;基于第一性原理对Co_(3)O_(4)晶胞进行相分析,对3种氮化物进行最高占据分子轨道(HOMO)-最低未占据分子轨道(LUMO)分析,计算了吸附构型的吸附能和最稳定吸附构型的Mulliken电荷转移与电子密度。结果表明:在15 mL模拟柴油中加入0.6 g Co_(3)O_(4),苯胺、吡啶、喹啉的最佳吸附温度分别为20、20和30℃,最佳吸附时间分别为30、30、40 min,吸附容量由大到小顺序均为苯胺>吡啶>喹啉。热力学与动力学分析表明,喹啉、吡啶、苯胺的吸附均更符合多分子层吸附的Freundlich模型和准二级动力学方程。HOMO-LUMO分析结果表明,Co_(3)O_(4)为电子接受体,3种氮化物为电子给予体,Co_(3)O_(4)对喹啉、吡啶的配位吸附结构最稳定,对苯胺的π络合吸附最稳定。电荷转移计算表明,苯胺、吡啶、喹啉向Co_(3)O_(4)团簇转移的电荷数分别为0.423、0.394、0.368,说明Co_(3)O_(4)吸附3种氮化物的吸附能力大小为苯胺>吡啶>喹啉;电子密度图结果表明,最稳定吸附结构中Co_(3)O_(4)与3种氮化物均形成了化学键。
