Five new aza-crown ethers have been prepared by the condensation of 2,6-bis[(2-formylphenyl)oxymethyl] pyridine with different diamino compounds in hot methanol, the bis-Schiff bases without isolation were reduced wit...Five new aza-crown ethers have been prepared by the condensation of 2,6-bis[(2-formylphenyl)oxymethyl] pyridine with different diamino compounds in hot methanol, the bis-Schiff bases without isolation were reduced with NaBH4 to afford the corresponding aza-crown ethers. The liquid membrane transport or alkali cations using the five new macrocycles as the ion-carriers was also studied.展开更多
Four new complexes of rare earths with a triaza crown ether (L) derived from N 3O 2 macro cycle 1,12,15 triaza 3, 4: 9,10 dibenzo 5, 8 dioxacycloheptadecane were synthesized and characterized by elemental ana...Four new complexes of rare earths with a triaza crown ether (L) derived from N 3O 2 macro cycle 1,12,15 triaza 3, 4: 9,10 dibenzo 5, 8 dioxacycloheptadecane were synthesized and characterized by elemental analysis, IR, molar conductance, TG DTA analysis and fluorescence spectra. The composition of the complexes determined as [RE(NO 3) 3L·3H 2O]·H 2O (RE=Sm, Eu, Tb and Dy). It is found that Sm 3+ , Eu 3+ , Tb 3+ and Dy 3+ complexes all show strong fluorescence emission in the solid state. Among these complexes, Tb 3+ complex has the strongest luminescence intensity. It shows that the ligand L triplet state energy matches 5D 4 energy level of Tb 3+ . In the Eu 3+ complex, η ( 5D 0→ 7F 2/ 5D 0→ 7F 1) is 2.6, which indicates that Eu 3+ locates at the asymmetric coordination field.展开更多
The synthesis of a new type of selena aza crown ether 6 (4 nitrobenzyl) 1,4,7,10 selenatriazacyclododecane (L) derivated from phenylalanine , and its platinum(Ⅱ) complex was described. The catalytic activity of...The synthesis of a new type of selena aza crown ether 6 (4 nitrobenzyl) 1,4,7,10 selenatriazacyclododecane (L) derivated from phenylalanine , and its platinum(Ⅱ) complex was described. The catalytic activity of this complex for the hydrosilylation of olefins by triethoxysilane was investigated.展开更多
The unsymmetrical bis-Schiff base manganese（III） and cobalt（II） complexes with either benzo-10-aza-crown ether pendants （MnL1Cl, MnLZCl） or morpholino pendant （MnL3Cl, CoL3） have been employed as models for hy...The unsymmetrical bis-Schiff base manganese（III） and cobalt（II） complexes with either benzo-10-aza-crown ether pendants （MnL1Cl, MnLZCl） or morpholino pendant （MnL3Cl, CoL3） have been employed as models for hy- drolase by studying the kinetics of their hydrolysis reactions with p-nitrophenyl picolinate （PNPP）. A kinetic model of PNPP cleavage catalyzed by these complexes is proposed. The effects of complex structures and reaction temperature on the rate of PNPP hydrolysis have been examined. All four complexes exhibit high catalytic activity and the rate increases with pH under 25℃. The complexes of ligands containing a crown ether group exhibit higher catalytic activities than the non-crown analogues. The catalytic activity of the complexes follows the order Mn（III） 〉 Co（II） under the same ligands.展开更多
Salen with two aza-crown ether pendants H2L1 and its analogues H2L2--H2L4 were successfully synthesized starting from benzo-10-aza-15-crown-5 (BN15C5) or morpholine. Their structures were characterized by IR, MS, H-1 ...Salen with two aza-crown ether pendants H2L1 and its analogues H2L2--H2L4 were successfully synthesized starting from benzo-10-aza-15-crown-5 (BN15C5) or morpholine. Their structures were characterized by IR, MS, H-1 NMR and elemental analysis, and were confirmed by X-ray diffraction analysis of H2L1. Moreover, the saturated oxygen uptake of their cobalt(II) complexes CoL1-CoL4 in diethyleneglycol dimethyl ether was determined at different temperature. The oxygenation contants ( K-O2) and thermodynamic parameters (DeltaHdegrees and DeltaSdegrees) were calculated. The modulation of O-2-binding capabilities by pendant substituents were investigated as compared with the parent Schiff base complex CoL5 (CoSalen). The results indicate that the dioxygen affinities of CoL have been much more enhanced by aza-crown pendants than that by morpholino pendants, and the O-2-binding capabilities of CoL1 and CoL2 with aza-crown pendants would also be enhanced by adding alkali metal cations.展开更多
基金We are gr ateful to the Natural Sc ience Foundation of Shandong Province for financial support ofthiswork (Q97B03123).
文摘Five new aza-crown ethers have been prepared by the condensation of 2,6-bis[(2-formylphenyl)oxymethyl] pyridine with different diamino compounds in hot methanol, the bis-Schiff bases without isolation were reduced with NaBH4 to afford the corresponding aza-crown ethers. The liquid membrane transport or alkali cations using the five new macrocycles as the ion-carriers was also studied.
文摘Four new complexes of rare earths with a triaza crown ether (L) derived from N 3O 2 macro cycle 1,12,15 triaza 3, 4: 9,10 dibenzo 5, 8 dioxacycloheptadecane were synthesized and characterized by elemental analysis, IR, molar conductance, TG DTA analysis and fluorescence spectra. The composition of the complexes determined as [RE(NO 3) 3L·3H 2O]·H 2O (RE=Sm, Eu, Tb and Dy). It is found that Sm 3+ , Eu 3+ , Tb 3+ and Dy 3+ complexes all show strong fluorescence emission in the solid state. Among these complexes, Tb 3+ complex has the strongest luminescence intensity. It shows that the ligand L triplet state energy matches 5D 4 energy level of Tb 3+ . In the Eu 3+ complex, η ( 5D 0→ 7F 2/ 5D 0→ 7F 1) is 2.6, which indicates that Eu 3+ locates at the asymmetric coordination field.
文摘The synthesis of a new type of selena aza crown ether 6 (4 nitrobenzyl) 1,4,7,10 selenatriazacyclododecane (L) derivated from phenylalanine , and its platinum(Ⅱ) complex was described. The catalytic activity of this complex for the hydrosilylation of olefins by triethoxysilane was investigated.
文摘The unsymmetrical bis-Schiff base manganese（III） and cobalt（II） complexes with either benzo-10-aza-crown ether pendants （MnL1Cl, MnLZCl） or morpholino pendant （MnL3Cl, CoL3） have been employed as models for hy- drolase by studying the kinetics of their hydrolysis reactions with p-nitrophenyl picolinate （PNPP）. A kinetic model of PNPP cleavage catalyzed by these complexes is proposed. The effects of complex structures and reaction temperature on the rate of PNPP hydrolysis have been examined. All four complexes exhibit high catalytic activity and the rate increases with pH under 25℃. The complexes of ligands containing a crown ether group exhibit higher catalytic activities than the non-crown analogues. The catalytic activity of the complexes follows the order Mn（III） 〉 Co（II） under the same ligands.
基金Project supported by the National Natural Science Foundation of China (Nos. 29572050 and 20072025).
文摘Salen with two aza-crown ether pendants H2L1 and its analogues H2L2--H2L4 were successfully synthesized starting from benzo-10-aza-15-crown-5 (BN15C5) or morpholine. Their structures were characterized by IR, MS, H-1 NMR and elemental analysis, and were confirmed by X-ray diffraction analysis of H2L1. Moreover, the saturated oxygen uptake of their cobalt(II) complexes CoL1-CoL4 in diethyleneglycol dimethyl ether was determined at different temperature. The oxygenation contants ( K-O2) and thermodynamic parameters (DeltaHdegrees and DeltaSdegrees) were calculated. The modulation of O-2-binding capabilities by pendant substituents were investigated as compared with the parent Schiff base complex CoL5 (CoSalen). The results indicate that the dioxygen affinities of CoL have been much more enhanced by aza-crown pendants than that by morpholino pendants, and the O-2-binding capabilities of CoL1 and CoL2 with aza-crown pendants would also be enhanced by adding alkali metal cations.
