A new modified carbon paste electrode based on cyclam as a modifier was prepared for the determination of Co(Ⅱ) ions. The proposed electrode shows a Nernstian slope 28.4 mV per decade over a wide concentration range ...A new modified carbon paste electrode based on cyclam as a modifier was prepared for the determination of Co(Ⅱ) ions. The proposed electrode shows a Nernstian slope 28.4 mV per decade over a wide concentration range 5.0×10 -6_1.0×10 -1 mol/L of Co 2+ ions with detection limit 2.5×10 -6 mol/L. The sensor exhibits good selectivities for Co 2+ over a wide variety of other cations. It can be used as an indicator electrode in potentiometric titration of cobalt(Ⅱ) ions as well as in direct determination of cobalt(Ⅱ) ions in wastewater of acidic cobalt electroplating bath. The electrode shows Nernestian behavior in a solution of 25% ethanol.展开更多
The spectroscopic properties for a recently synthesized hetero-metallo- binuclear complex Ru(bpy)_2 (bpy-cyclam-Ni)^(4+)(3)and its related complexes 1 and 2 were investigated by UV-vis and emission spectral methods.A ...The spectroscopic properties for a recently synthesized hetero-metallo- binuclear complex Ru(bpy)_2 (bpy-cyclam-Ni)^(4+)(3)and its related complexes 1 and 2 were investigated by UV-vis and emission spectral methods.A drastic quenching of fluorescence from the Ru(bpy)_3^(2+) subunit by the covalently attached quencher sub- unit Ni(cyclam)^(2+) was observed for complex 3,and the mechanism was discussed.展开更多
We explore the detailed mechanism for the reduction reaction through systematic theoretical calculations,and the Ni-cyclam catalyst for the homogeneous CO_(2) reduction reaction exhibits high efficiency.We find that t...We explore the detailed mechanism for the reduction reaction through systematic theoretical calculations,and the Ni-cyclam catalyst for the homogeneous CO_(2) reduction reaction exhibits high efficiency.We find that the first hydrogen transfer step is the rate-determining step for the reaction.Our simulation results show that both the acidity of the environment and substituents play critical roles in the CO_(2) reduction reaction.The strong electron-withdrawing substituent perpendicular to the C atoms at the 5,6,12,14-position of cyclam decreases the energy barrier of the rate-determining step significantly.Moreover,we reveal the mechanism through density functional theory calculations,which exhibits the intra-molecular H-transfer feature and thus explains the extraordinary reactivity seen during the reaction in previous works.All the results ensure a good future for such series of Ni-cyclam catalysts.展开更多
In this paper, we show that sweet quaternary ammonium, pyridinium, and imidazolium cyclamates are cheap, thermally stable, surface and biologically active ionic liquids, with potential application as feeding deterrents.
文摘A new modified carbon paste electrode based on cyclam as a modifier was prepared for the determination of Co(Ⅱ) ions. The proposed electrode shows a Nernstian slope 28.4 mV per decade over a wide concentration range 5.0×10 -6_1.0×10 -1 mol/L of Co 2+ ions with detection limit 2.5×10 -6 mol/L. The sensor exhibits good selectivities for Co 2+ over a wide variety of other cations. It can be used as an indicator electrode in potentiometric titration of cobalt(Ⅱ) ions as well as in direct determination of cobalt(Ⅱ) ions in wastewater of acidic cobalt electroplating bath. The electrode shows Nernestian behavior in a solution of 25% ethanol.
文摘The spectroscopic properties for a recently synthesized hetero-metallo- binuclear complex Ru(bpy)_2 (bpy-cyclam-Ni)^(4+)(3)and its related complexes 1 and 2 were investigated by UV-vis and emission spectral methods.A drastic quenching of fluorescence from the Ru(bpy)_3^(2+) subunit by the covalently attached quencher sub- unit Ni(cyclam)^(2+) was observed for complex 3,and the mechanism was discussed.
基金funded by the National Key R&D Program of China(2020YFA0406202)Natural Science Foundation of China,grant number No.22008006,22090042 and 21731001the Fundamental Research Funds for the Central Universities,grant number No.FRF-IDRY-20-005 and FRF-TP-20-077A1.
文摘We explore the detailed mechanism for the reduction reaction through systematic theoretical calculations,and the Ni-cyclam catalyst for the homogeneous CO_(2) reduction reaction exhibits high efficiency.We find that the first hydrogen transfer step is the rate-determining step for the reaction.Our simulation results show that both the acidity of the environment and substituents play critical roles in the CO_(2) reduction reaction.The strong electron-withdrawing substituent perpendicular to the C atoms at the 5,6,12,14-position of cyclam decreases the energy barrier of the rate-determining step significantly.Moreover,we reveal the mechanism through density functional theory calculations,which exhibits the intra-molecular H-transfer feature and thus explains the extraordinary reactivity seen during the reaction in previous works.All the results ensure a good future for such series of Ni-cyclam catalysts.
基金the National Science Centre (Poland) for financial support (7548/B/H03/2011/40)
文摘In this paper, we show that sweet quaternary ammonium, pyridinium, and imidazolium cyclamates are cheap, thermally stable, surface and biologically active ionic liquids, with potential application as feeding deterrents.
