Under the action of CS2 and KOH in dioxane solution, calixarene derivative 2 was converted into calixarene derivative containing xanthate salt (3) and its Ni2+ complex compound 4 was prepared by self-assembled reactio...Under the action of CS2 and KOH in dioxane solution, calixarene derivative 2 was converted into calixarene derivative containing xanthate salt (3) and its Ni2+ complex compound 4 was prepared by self-assembled reaction with NiSO4 further. The structures of new compounds were confirmed by elemental analyses, IR, UV, 1H NMR, MS techniques. The Ni2+ of complex compound 4 was in high-spin state by its ESR spectrum.展开更多
The electronic structures of the species Ni(DMG)_2, (Ni(DMG)_2)^- and (Ni(DMG)_2)_(2-) have been studied by INDO quantum chemical method. The results have clearly shown that in the first stage of the electroreduction ...The electronic structures of the species Ni(DMG)_2, (Ni(DMG)_2)^- and (Ni(DMG)_2)_(2-) have been studied by INDO quantum chemical method. The results have clearly shown that in the first stage of the electroreduction of Ni(DMG)_2, one electron interacts with the d orbitals on the nickel atom, while in the further stage the second electron interacts with the p orbitals on the nitrogen atoms. It conforms with our electrochemical experimental studies which showed that not only Ni(Ⅱ) is reduced but also DMG is catalytically reduced during the reduction of Ni(DMG)_2.展开更多
采用B3LYP/6-31++G(d,p)方法研究Ni^(2+)催化甘氨酸质子迁移机理.优化得到了7个中性配合物和1个两性配合物;两性的最稳定,结合能为-927.3 k J/mol.分子内单键旋转和羧基H在2个羧基O原子间的迁移导致中性构型转化,C-C键旋转的能垒低于21....采用B3LYP/6-31++G(d,p)方法研究Ni^(2+)催化甘氨酸质子迁移机理.优化得到了7个中性配合物和1个两性配合物;两性的最稳定,结合能为-927.3 k J/mol.分子内单键旋转和羧基H在2个羧基O原子间的迁移导致中性构型转化,C-C键旋转的能垒低于21.9 k J/mol,C-O键旋转的能垒在23.1-46.4 k J/mol范围内,羧基H在O原子间迁移的正逆反应能垒分别为175.0和108.3 k J/mol.羧基H迁移到氨基生成两性构型,能垒为19.3k J/mol.Ni^(2+)导致氨基N原子负电荷减少0.48,削弱了N原子对羧基H原子的库仑吸引,钝化了共价键B_(O3–H6),动力学上不利于羧基H迁移;但是羧基H迁移后,形成的两性构型却是热力学最稳定体系.最稳定中性构型N1转化为最稳定两性构型Z1的路径为:N1→N1-N7→N7→N3-N7→N3→N3-N5→N5→N5-Z1→Z1,该路径的最高能垒为124.8 k J/mol.展开更多
The catalytic performance of Ni( η 5 Ind) 2 complex in the dimerization of propylene was studied in combination with an organoaluminum co catalyst, eventually in the presence of a phosphine ligand. The effects...The catalytic performance of Ni( η 5 Ind) 2 complex in the dimerization of propylene was studied in combination with an organoaluminum co catalyst, eventually in the presence of a phosphine ligand. The effects of the type of aluminum co catalyst and its relative amount, the nature of phosphine ligand and P/Ni ratio as well as the reaction temperature were examined. The results indicated that the nickel precatalyst exhibited high productivity for the propylene dimerization together with organoaluminum. It was likely to strongly modify the reactivity in the catalytic system when using phosphine ligand as additives, especially at the reaction temperature below 0 ℃. The catalytic system based on Ni( η 5 Ind) 2 complex displayed an extremely high productivity (TOF up to 169000 h -1 ) and a good regioselectivity to 2,3 dimethylbutenes (2,3 DMB) in dimers (66 4%) under proper reaction parameters.展开更多
文摘Under the action of CS2 and KOH in dioxane solution, calixarene derivative 2 was converted into calixarene derivative containing xanthate salt (3) and its Ni2+ complex compound 4 was prepared by self-assembled reaction with NiSO4 further. The structures of new compounds were confirmed by elemental analyses, IR, UV, 1H NMR, MS techniques. The Ni2+ of complex compound 4 was in high-spin state by its ESR spectrum.
基金Project supported by the National Natural Science Foundstion of China.
文摘The electronic structures of the species Ni(DMG)_2, (Ni(DMG)_2)^- and (Ni(DMG)_2)_(2-) have been studied by INDO quantum chemical method. The results have clearly shown that in the first stage of the electroreduction of Ni(DMG)_2, one electron interacts with the d orbitals on the nickel atom, while in the further stage the second electron interacts with the p orbitals on the nitrogen atoms. It conforms with our electrochemical experimental studies which showed that not only Ni(Ⅱ) is reduced but also DMG is catalytically reduced during the reduction of Ni(DMG)_2.
文摘采用B3LYP/6-31++G(d,p)方法研究Ni^(2+)催化甘氨酸质子迁移机理.优化得到了7个中性配合物和1个两性配合物;两性的最稳定,结合能为-927.3 k J/mol.分子内单键旋转和羧基H在2个羧基O原子间的迁移导致中性构型转化,C-C键旋转的能垒低于21.9 k J/mol,C-O键旋转的能垒在23.1-46.4 k J/mol范围内,羧基H在O原子间迁移的正逆反应能垒分别为175.0和108.3 k J/mol.羧基H迁移到氨基生成两性构型,能垒为19.3k J/mol.Ni^(2+)导致氨基N原子负电荷减少0.48,削弱了N原子对羧基H原子的库仑吸引,钝化了共价键B_(O3–H6),动力学上不利于羧基H迁移;但是羧基H迁移后,形成的两性构型却是热力学最稳定体系.最稳定中性构型N1转化为最稳定两性构型Z1的路径为:N1→N1-N7→N7→N3-N7→N3→N3-N5→N5→N5-Z1→Z1,该路径的最高能垒为124.8 k J/mol.
文摘The catalytic performance of Ni( η 5 Ind) 2 complex in the dimerization of propylene was studied in combination with an organoaluminum co catalyst, eventually in the presence of a phosphine ligand. The effects of the type of aluminum co catalyst and its relative amount, the nature of phosphine ligand and P/Ni ratio as well as the reaction temperature were examined. The results indicated that the nickel precatalyst exhibited high productivity for the propylene dimerization together with organoaluminum. It was likely to strongly modify the reactivity in the catalytic system when using phosphine ligand as additives, especially at the reaction temperature below 0 ℃. The catalytic system based on Ni( η 5 Ind) 2 complex displayed an extremely high productivity (TOF up to 169000 h -1 ) and a good regioselectivity to 2,3 dimethylbutenes (2,3 DMB) in dimers (66 4%) under proper reaction parameters.
