EPR spectra of three new quaternary gadolinium complexes(I： [Gd(C6H5COO)2(NO3)(bipy)]2,Ⅱ： [Gd(m- CH3C6H4COO)2(NO3)(phen)]2 andⅢ： [Gd(p- CH3C6H4COO)(NO3)(phen)]2) with mixed anion ligands in polycrystalline powder...EPR spectra of three new quaternary gadolinium complexes(I： [Gd(C6H5COO)2(NO3)(bipy)]2,Ⅱ： [Gd(m- CH3C6H4COO)2(NO3)(phen)]2 andⅢ： [Gd(p- CH3C6H4COO)(NO3)(phen)]2) with mixed anion ligands in polycrystalline powders and solutions have been investigated at different temperatures and solvents.New behavior of EPR spectra of complexⅢ was first observed in polycrystalline powder at 77K and three types of EPR spectra for three complexes,symmetry resonance spectrum for the complexⅡ ,U spectrum for the complexⅢ ,and asymmetry resonance spectrum for the complex I.The relationship of EPR features between the crystal- field strength in the complexes and local symmetry around Gd(Ⅲ ) was discussed.The crystal- field parameters b20 and asymmetry parametersλ′ of the complexes I andⅢ were estimated.展开更多
The crystal and molecular structures of K[Eu~Ⅲ(edta)(H_2O)_3]·3.5H_2O (H_4 edta=ethylenediaminetetraacetic acid) and K_4[Eu~~Ⅲ__2(Httha)_2]·13.5H_2O (H_6 ttha=triethylenetetraminehexaacetic acid) complexes...The crystal and molecular structures of K[Eu~Ⅲ(edta)(H_2O)_3]·3.5H_2O (H_4 edta=ethylenediaminetetraacetic acid) and K_4[Eu~~Ⅲ__2(Httha)_2]·13.5H_2O (H_6 ttha=triethylenetetraminehexaacetic acid) complexes were determined by single-crystal X-ray structure analyses. The crystal of K[Eu~Ⅲ(edta)(H_2O)_3]·3.5H_2O complex belongs to orthorhombic crystal system and Fdd2 space group. The crystal data are as follows: a=1.9849(6)nm, b=3.5598(11)nm, c=1.2222(4)nm, V=8.636(5)nm^3, Z=16, M=596.37, D_c=1.835 g·cm^(-3), μ=3.166 mm^(-1) and F(000)=4752. The final R and wR values are 0.0269 and 0.0692 for 2936 [I>2.0σ(I)] reflections, and 0.0317 and 0.0708 for all 7284 unique reflections, respectively. The [Eu~Ⅲ(edta)(H_2O)_3]-complex anion has a nine-coordinate pseudo-monocapped square antiprismatic structure in which the nine coordinate atoms, two N and seven O are from one edta ligand and three water molecules. The crystal of the K_4[Eu~Ⅲ_2(Httha)_2]·13.5H_2O complex belongs to monoclinic system and P2(1)/n space group. The crystal data are as follows: a=1.1337(3) nm, b=2.5753(6) nm, c=2.2138(6) nm, β=102.871(5)°, V=6.301(3) nm^3, Z=4, M=1682.33, D_c=1.773 g·cm^(-3), μ=2.339 mm^(-1) and F(000)=3404. The final R and wR are 0.0514 and 0.0906 for 11144 [I>2.0σ(I)] reflections, and 0.0976 and 0.1068 for all 26048 unique reflections, respectively. The complex molecule is composed of two close parts in structure. Every part around the Eu~Ⅲ ion in the [Eu~~Ⅲ__2(Httha)_2]^(4-) complex anion has a nine-coordinate structure with distorted monocapped square antiprismatic prism, in which the ttha ligand coordinates to one central Eu~Ⅲ ion with three N atoms and four O atoms and to the other Eu~Ⅲ ion with two O atoms.展开更多
Superoxide anion,one of the most active reactive oxygen species,is associated with the development of many diseases.So monitoring superoxide anion in living cells is of great significance for the pathological research...Superoxide anion,one of the most active reactive oxygen species,is associated with the development of many diseases.So monitoring superoxide anion in living cells is of great significance for the pathological research of many diseases.In this work,a new non-enzymatic sensor tor the detection of superoxide anion(O^·-2)was developed,which was iabricated by the nanocomposites composed of manganese(Ⅲ)tetraphenyl porphine(MnTPP)as superoxide dismutase mimic and electrochemical reduced graphene oxide(ERGO)as electrode support material to modify the glassy carbon electrode(GCE).The electrochemical behavior of the fabricated electrode(MiiTPP/ERGO/GCE)was performed by electrochemical impedance spectroscopy(EIS)and cyclic voltammetry(CV),which revealed that MnTPP/ERGO/GCE possessed good catalytic ability to theelectrochemical reduction of O^·-2.The MnTPP/ERGO/GCE showed excellent electroanalysis perfonnance towards O^·-2 using the technique of diflerential pulse voltanimetry(DPV)with a linear relationship in the range of 0.2—110.0μmol/L,a sensitivity of 445 μA· L·mmol^-1·cm^- 2 and a detection limit of 0.039 μmol/L(S/N=3).The real-time monitoring of O^·-2 from MCF-7 breast cancer cells stimulated by zymosan was realized in this work,which indicates that the MnTPP/ERGO/GCE hold potential application for electrochemical quantification of superoxide anions in biological applications.展开更多
文摘EPR spectra of three new quaternary gadolinium complexes(I： [Gd(C6H5COO)2(NO3)(bipy)]2,Ⅱ： [Gd(m- CH3C6H4COO)2(NO3)(phen)]2 andⅢ： [Gd(p- CH3C6H4COO)(NO3)(phen)]2) with mixed anion ligands in polycrystalline powders and solutions have been investigated at different temperatures and solvents.New behavior of EPR spectra of complexⅢ was first observed in polycrystalline powder at 77K and three types of EPR spectra for three complexes,symmetry resonance spectrum for the complexⅡ ,U spectrum for the complexⅢ ,and asymmetry resonance spectrum for the complex I.The relationship of EPR features between the crystal- field strength in the complexes and local symmetry around Gd(Ⅲ ) was discussed.The crystal- field parameters b20 and asymmetry parametersλ′ of the complexes I andⅢ were estimated.
文摘The crystal and molecular structures of K[Eu~Ⅲ(edta)(H_2O)_3]·3.5H_2O (H_4 edta=ethylenediaminetetraacetic acid) and K_4[Eu~~Ⅲ__2(Httha)_2]·13.5H_2O (H_6 ttha=triethylenetetraminehexaacetic acid) complexes were determined by single-crystal X-ray structure analyses. The crystal of K[Eu~Ⅲ(edta)(H_2O)_3]·3.5H_2O complex belongs to orthorhombic crystal system and Fdd2 space group. The crystal data are as follows: a=1.9849(6)nm, b=3.5598(11)nm, c=1.2222(4)nm, V=8.636(5)nm^3, Z=16, M=596.37, D_c=1.835 g·cm^(-3), μ=3.166 mm^(-1) and F(000)=4752. The final R and wR values are 0.0269 and 0.0692 for 2936 [I>2.0σ(I)] reflections, and 0.0317 and 0.0708 for all 7284 unique reflections, respectively. The [Eu~Ⅲ(edta)(H_2O)_3]-complex anion has a nine-coordinate pseudo-monocapped square antiprismatic structure in which the nine coordinate atoms, two N and seven O are from one edta ligand and three water molecules. The crystal of the K_4[Eu~Ⅲ_2(Httha)_2]·13.5H_2O complex belongs to monoclinic system and P2(1)/n space group. The crystal data are as follows: a=1.1337(3) nm, b=2.5753(6) nm, c=2.2138(6) nm, β=102.871(5)°, V=6.301(3) nm^3, Z=4, M=1682.33, D_c=1.773 g·cm^(-3), μ=2.339 mm^(-1) and F(000)=3404. The final R and wR are 0.0514 and 0.0906 for 11144 [I>2.0σ(I)] reflections, and 0.0976 and 0.1068 for all 26048 unique reflections, respectively. The complex molecule is composed of two close parts in structure. Every part around the Eu~Ⅲ ion in the [Eu~~Ⅲ__2(Httha)_2]^(4-) complex anion has a nine-coordinate structure with distorted monocapped square antiprismatic prism, in which the ttha ligand coordinates to one central Eu~Ⅲ ion with three N atoms and four O atoms and to the other Eu~Ⅲ ion with two O atoms.
基金Supported by the National Natural Science Foundation of China(No.81872669)the Scientific Research Projects of the Department of Education of Hebei Province,China(Nos.ZD2018037,QN2019140).
文摘Superoxide anion,one of the most active reactive oxygen species,is associated with the development of many diseases.So monitoring superoxide anion in living cells is of great significance for the pathological research of many diseases.In this work,a new non-enzymatic sensor tor the detection of superoxide anion(O^·-2)was developed,which was iabricated by the nanocomposites composed of manganese(Ⅲ)tetraphenyl porphine(MnTPP)as superoxide dismutase mimic and electrochemical reduced graphene oxide(ERGO)as electrode support material to modify the glassy carbon electrode(GCE).The electrochemical behavior of the fabricated electrode(MiiTPP/ERGO/GCE)was performed by electrochemical impedance spectroscopy(EIS)and cyclic voltammetry(CV),which revealed that MnTPP/ERGO/GCE possessed good catalytic ability to theelectrochemical reduction of O^·-2.The MnTPP/ERGO/GCE showed excellent electroanalysis perfonnance towards O^·-2 using the technique of diflerential pulse voltanimetry(DPV)with a linear relationship in the range of 0.2—110.0μmol/L,a sensitivity of 445 μA· L·mmol^-1·cm^- 2 and a detection limit of 0.039 μmol/L(S/N=3).The real-time monitoring of O^·-2 from MCF-7 breast cancer cells stimulated by zymosan was realized in this work,which indicates that the MnTPP/ERGO/GCE hold potential application for electrochemical quantification of superoxide anions in biological applications.
