The authors have designed and synthesized new chiral salen-type metal （M = Fe, Co, Ni, Cu, Zn） complexes （1-5） for new conceptual dyes （co-sensitizer or colorful multi-dyes） of DSSCs （dye-sensitized solar cells...The authors have designed and synthesized new chiral salen-type metal （M = Fe, Co, Ni, Cu, Zn） complexes （1-5） for new conceptual dyes （co-sensitizer or colorful multi-dyes） of DSSCs （dye-sensitized solar cells）. The authors measured substituent effects on their absorption spectra and redox properties, and compared them with TD-DFT （time-dependent density functional theory） calculations. Electron withdrawing groups resulted in red-shift of ultraviolet-visible （UV-Vis） spectra. For the first time, the authors also proposed and confirmed the importance of substituent effects on their electric transition dipole moments, calculated by TD-DFT for designing dyes. Chemisorption for TiO2 of the complex by carboxyl groups was confirmed by XPS measurement. In view of electronic properties, all compounds have the possibility to be dyes of DSSCs.展开更多
A nickel salen complex was encapsulated in the supercages of nanozeolite NaA,LTA(linde type A)structure,using the flexible ligand method.The electrochemical behavior and electrocatalytic activity of a carbon paste ele...A nickel salen complex was encapsulated in the supercages of nanozeolite NaA,LTA(linde type A)structure,using the flexible ligand method.The electrochemical behavior and electrocatalytic activity of a carbon paste electrode(CPE)modified with Ni(II)‐Salen‐A(Ni(II)‐SalenA/CPE)for hydrazine oxidation in0.1mol/L NaOH solution were investigated by cyclic voltammetry,chronoamperometry,and chronocoulometry.First,organic‐template‐free synthesis of nanozeolite LTA was performed and the obtained material was characterized by various techniques.The average particle size of the LTA crystals was estimated to be56.1and72nm by X‐ray diffraction and particle size analysis,respectively.The electron transfer coefficient was found to be0.64and the catalytic rate constant for oxidation of hydrazine at the redox sites of Ni(II)‐SalenA/CPE was found to be1.03×105cm3/(mol·s).Investigation of the electrocatalytic mechanism suggested that oxidation of hydrazine occurred through reaction with Ni3+(Salen)O(OH)and also direct electrooxidation.The anodic peak currents revealed a linear dependence on the square root of the scan rate,indicating a diffusion‐controlled process,and the diffusion coefficient of hydrazine was found to be1.18×10?7cm2/s.The results indicated that Ni(II)‐SalenA/CPE displays good electrocatalytic activity toward hydrazine oxidation owing to the porous structure of nanozeolite LTA and the Ni(II)‐Salen complex.Finally,the general reaction mechanism for the electrooxidation of hydrazine on Ni(II)‐SalenA/CPE in alkaline solution involves the transfer of four electrons,in which the first electron transfer reaction acts as the rate‐limiting step followed by a three‐electron process to generate environmentally friendly nitrogen and water as final products.展开更多
Jacobsen's catalyst was immobilized onto SBA-15 by multi-step grafting, and this heterogenized catalyst exhibited comparable catalytic performance with the corresponding homogeneous counterpart for the epoxidation...Jacobsen's catalyst was immobilized onto SBA-15 by multi-step grafting, and this heterogenized catalyst exhibited comparable catalytic performance with the corresponding homogeneous counterpart for the epoxidation of alkenes, and the catalyst could be recycled effectively several times.展开更多
The asymmetric ring-opening of epoxides with dithiophosphorus acids catalyzed by a （salen）Ti（Ⅳ） complex formed in situ from the reaction of Ti（OPr-i）4 and the chiral Schiff base derived from （1R,2R）-（＋）-di...The asymmetric ring-opening of epoxides with dithiophosphorus acids catalyzed by a （salen）Ti（Ⅳ） complex formed in situ from the reaction of Ti（OPr-i）4 and the chiral Schiff base derived from （1R,2R）-（＋）-diaminocyclohexane was realized. The resulting products were obtained with low to good enantioselectivity （up to 73% ee）.展开更多
A homochrial manganese（Ⅲ） complex（1） derived from chiral salen ligand（1 R,2 R）-（-）-1,2-diphenylethane-1,2-diamine-N,N？-bicarboxyl-salicylidene） has been synthesized through solvothermal procedure and charac...A homochrial manganese（Ⅲ） complex（1） derived from chiral salen ligand（1 R,2 R）-（-）-1,2-diphenylethane-1,2-diamine-N,N？-bicarboxyl-salicylidene） has been synthesized through solvothermal procedure and characterized by IR,elemental analysis,TGA,circular dichroism（CD）,powder and single-crystal X-ray crystallography.It crystallizes in orthorhombic,space group P212121 with a = 9.108（3）,b = 16.431（5）,c = 26.531（6） A,V = 3970.4（19） A^3,Z = 4,Dc = 1.248 g/cm^3,F（000） = 1568,Mr = 745.73,μ = 0.383 mm^-1,the final GOOF = 0.957,R = 0.0631 and wR = 0.1079 for 13250 observed reflections with I 〉 2σ（I）.The coordination polymer 1 possesses a 1 D infinite zigzag chain architecture constructed by the dicarboxyl-functionalized metallosalen ligand（Mn-salen）,and the polymeric chains are further assembled into a 3D supramolecular network structure via strong intermolecular hydrogen bonding interactions between adjacent zigzag chains.As a heterogeneous catalyst,1 was used as an efficient heterogeneous catalyst for the asymmetric olefin epoxidation.展开更多
The molecular recognition behavior of the chiral salen-metalcomplexes towards vip molecules, such as imidazole deriva-tives and amino-acid ester, was systematically investigated bymeans of circular dichroism (CD) sp...The molecular recognition behavior of the chiral salen-metalcomplexes towards vip molecules, such as imidazole deriva-tives and amino-acid ester, was systematically investigated bymeans of circular dichroism (CD) spectra. The coordinationnumbers of the host-vip complexes as well as the recognitioncapability of the salen-metal complexes were explained by char-acter and intensity analyses of the CD spectra.展开更多
Three new homochiral bis-diamine-bridged bi-Mn（salen） complexes were synthesized. Their catalysis on asymmetric epoxidation of a-methylstyrene, styrene and indene was studied with NaC10 and m-CPBA as oxidants respec...Three new homochiral bis-diamine-bridged bi-Mn（salen） complexes were synthesized. Their catalysis on asymmetric epoxidation of a-methylstyrene, styrene and indene was studied with NaC10 and m-CPBA as oxidants respectively. This homogeneous catalyst exhibited comparable catalytic activity and enantioselectivity to the Jacobsen＇s catalyst in the asymmetric epoxidation of unfunctionalized olefins. Furthermore, the catalyst could be conveniently recovered and reused at least five times without significant losses of both activity and enantioselectivity. Specially, it also could be efficiently used in large-scale reactions with superior catalytic disposition being maintained at the same level, which provided the potential for the applications in industry. The effect of axial bases, temperature and solvent on activity and enantioselectivity of the catalytic system were also studied.展开更多
Spin-crossover(SCO)metal complexes are expected to be widely used in data storage materials,display devices and sensors.Although a lot of spin-crossover photoswitches have been developed,the reversible photomodulation...Spin-crossover(SCO)metal complexes are expected to be widely used in data storage materials,display devices and sensors.Although a lot of spin-crossover photoswitches have been developed,the reversible photomodulation cases that work at room temperature are limited.Herein,a novel cobalt complex o-1-Co(II)wherein the salen unit bridges with bis-diarylethene has been designed as switch to construct"off-on"logic operation at room temperature.The complex o-1-Co(II)displays an abrupt,reversible and hysteretic spin crossover(T1/2↓=166 K,T1/2↑=177 K,andΔT1/2=11 K)between the high-spin(HS)and low-spin(LS)states.Meanwhile,photocyclization of o-1-Co(II)with UV light produces a photoresponsive closed form c-1-Co(II),which always stays at low-spin without SCO at all.Moreover,the magnetic switching of the complex can also be achieved with redox reactions between Co(II)and Co(III).展开更多
文摘The authors have designed and synthesized new chiral salen-type metal （M = Fe, Co, Ni, Cu, Zn） complexes （1-5） for new conceptual dyes （co-sensitizer or colorful multi-dyes） of DSSCs （dye-sensitized solar cells）. The authors measured substituent effects on their absorption spectra and redox properties, and compared them with TD-DFT （time-dependent density functional theory） calculations. Electron withdrawing groups resulted in red-shift of ultraviolet-visible （UV-Vis） spectra. For the first time, the authors also proposed and confirmed the importance of substituent effects on their electric transition dipole moments, calculated by TD-DFT for designing dyes. Chemisorption for TiO2 of the complex by carboxyl groups was confirmed by XPS measurement. In view of electronic properties, all compounds have the possibility to be dyes of DSSCs.
文摘A nickel salen complex was encapsulated in the supercages of nanozeolite NaA,LTA(linde type A)structure,using the flexible ligand method.The electrochemical behavior and electrocatalytic activity of a carbon paste electrode(CPE)modified with Ni(II)‐Salen‐A(Ni(II)‐SalenA/CPE)for hydrazine oxidation in0.1mol/L NaOH solution were investigated by cyclic voltammetry,chronoamperometry,and chronocoulometry.First,organic‐template‐free synthesis of nanozeolite LTA was performed and the obtained material was characterized by various techniques.The average particle size of the LTA crystals was estimated to be56.1and72nm by X‐ray diffraction and particle size analysis,respectively.The electron transfer coefficient was found to be0.64and the catalytic rate constant for oxidation of hydrazine at the redox sites of Ni(II)‐SalenA/CPE was found to be1.03×105cm3/(mol·s).Investigation of the electrocatalytic mechanism suggested that oxidation of hydrazine occurred through reaction with Ni3+(Salen)O(OH)and also direct electrooxidation.The anodic peak currents revealed a linear dependence on the square root of the scan rate,indicating a diffusion‐controlled process,and the diffusion coefficient of hydrazine was found to be1.18×10?7cm2/s.The results indicated that Ni(II)‐SalenA/CPE displays good electrocatalytic activity toward hydrazine oxidation owing to the porous structure of nanozeolite LTA and the Ni(II)‐Salen complex.Finally,the general reaction mechanism for the electrooxidation of hydrazine on Ni(II)‐SalenA/CPE in alkaline solution involves the transfer of four electrons,in which the first electron transfer reaction acts as the rate‐limiting step followed by a three‐electron process to generate environmentally friendly nitrogen and water as final products.
文摘Jacobsen's catalyst was immobilized onto SBA-15 by multi-step grafting, and this heterogenized catalyst exhibited comparable catalytic performance with the corresponding homogeneous counterpart for the epoxidation of alkenes, and the catalyst could be recycled effectively several times.
基金the National Natural Science Foundation of China(No.20472033)the Ph.D Programs of Ministry of Education of China for generous financial support for our programs.
文摘The asymmetric ring-opening of epoxides with dithiophosphorus acids catalyzed by a （salen）Ti（Ⅳ） complex formed in situ from the reaction of Ti（OPr-i）4 and the chiral Schiff base derived from （1R,2R）-（＋）-diaminocyclohexane was realized. The resulting products were obtained with low to good enantioselectivity （up to 73% ee）.
基金supported by NSFC-21371119,21431004,21401128,21522104 and 21620102001the National Key Basic Research Program of China(No.2014CB932102 and 2016YFA0203400)the Shanghai“Eastern Scholar”Program
文摘A homochrial manganese（Ⅲ） complex（1） derived from chiral salen ligand（1 R,2 R）-（-）-1,2-diphenylethane-1,2-diamine-N,N？-bicarboxyl-salicylidene） has been synthesized through solvothermal procedure and characterized by IR,elemental analysis,TGA,circular dichroism（CD）,powder and single-crystal X-ray crystallography.It crystallizes in orthorhombic,space group P212121 with a = 9.108（3）,b = 16.431（5）,c = 26.531（6） A,V = 3970.4（19） A^3,Z = 4,Dc = 1.248 g/cm^3,F（000） = 1568,Mr = 745.73,μ = 0.383 mm^-1,the final GOOF = 0.957,R = 0.0631 and wR = 0.1079 for 13250 observed reflections with I 〉 2σ（I）.The coordination polymer 1 possesses a 1 D infinite zigzag chain architecture constructed by the dicarboxyl-functionalized metallosalen ligand（Mn-salen）,and the polymeric chains are further assembled into a 3D supramolecular network structure via strong intermolecular hydrogen bonding interactions between adjacent zigzag chains.As a heterogeneous catalyst,1 was used as an efficient heterogeneous catalyst for the asymmetric olefin epoxidation.
基金Project supported by the National Natural Science Foundation of China(Nos.20171024 and 20271030),the Natural Science Foundation of Tianjin(No.023604011),and the Research Fund for Returning Scholars from Abroad.
文摘The molecular recognition behavior of the chiral salen-metalcomplexes towards vip molecules, such as imidazole deriva-tives and amino-acid ester, was systematically investigated bymeans of circular dichroism (CD) spectra. The coordinationnumbers of the host-vip complexes as well as the recognitioncapability of the salen-metal complexes were explained by char-acter and intensity analyses of the CD spectra.
基金financially supported by National Ministry of Science and Technology Innovation Fund for High-tech Small and Medium Enterprise Technology (09C26215112399)National Ministry of Human Resources and Social Security Start-up Support Projects for Students Returned to Business, Office of Human Resources and Social Security Issued 2009 (143)
文摘Three new homochiral bis-diamine-bridged bi-Mn（salen） complexes were synthesized. Their catalysis on asymmetric epoxidation of a-methylstyrene, styrene and indene was studied with NaC10 and m-CPBA as oxidants respectively. This homogeneous catalyst exhibited comparable catalytic activity and enantioselectivity to the Jacobsen＇s catalyst in the asymmetric epoxidation of unfunctionalized olefins. Furthermore, the catalyst could be conveniently recovered and reused at least five times without significant losses of both activity and enantioselectivity. Specially, it also could be efficiently used in large-scale reactions with superior catalytic disposition being maintained at the same level, which provided the potential for the applications in industry. The effect of axial bases, temperature and solvent on activity and enantioselectivity of the catalytic system were also studied.
基金the National Natural Science Foundation of China for the Science Center Program(21788102)the Creative Research Groups(21421004)and Key Project(21636002)+6 种基金the National Natural Science Foundation of China(21905091)the Shanghai Municipal Science and Technology Major Project(Grant 2018SHZDZX03)the Innovation Program of Shanghai Municipal Education CommissionScientific Committee of Shanghai(15XD1501400)the Program of Introducing Talents of Discipline to Universities(B16017)the Shanghai Pujiang Program(18PJ1402200)China Postdoctoral Science Foundation(2019M651418)。
文摘Spin-crossover(SCO)metal complexes are expected to be widely used in data storage materials,display devices and sensors.Although a lot of spin-crossover photoswitches have been developed,the reversible photomodulation cases that work at room temperature are limited.Herein,a novel cobalt complex o-1-Co(II)wherein the salen unit bridges with bis-diarylethene has been designed as switch to construct"off-on"logic operation at room temperature.The complex o-1-Co(II)displays an abrupt,reversible and hysteretic spin crossover(T1/2↓=166 K,T1/2↑=177 K,andΔT1/2=11 K)between the high-spin(HS)and low-spin(LS)states.Meanwhile,photocyclization of o-1-Co(II)with UV light produces a photoresponsive closed form c-1-Co(II),which always stays at low-spin without SCO at all.Moreover,the magnetic switching of the complex can also be achieved with redox reactions between Co(II)and Co(III).
