A new cucurbit[6]uril bridsed binuclear complex {[Gd（H2O）6]2[Q6（H2O）]}C16·4H2O, where Q6 represents cucurbit[6]uril, has been synthesized and characterized by X-ray diffraction. The crystal structure shows th...A new cucurbit[6]uril bridsed binuclear complex {[Gd（H2O）6]2[Q6（H2O）]}C16·4H2O, where Q6 represents cucurbit[6]uril, has been synthesized and characterized by X-ray diffraction. The crystal structure shows that the complex has an extended cucurbit[6]uril-bridged structure consisting of two gadolinium（Ⅲ） ions, in which each gadolinium（Ⅲ） ion is coordinated with two neighboring carbonylic oxygen atoms of Q6 and six oxygen atoms of water molecules that leans toward one side of the portal. One disordered guest water molecule resides in the Q6 molecule cavity and occupies two different positions. Hydrogen bonds assemble the complcx to threedimensional supramolecular structure.展开更多
A new quaternary mixed anion complex of gadolinium(Ⅲ), [Gd(CH 3CH 2COO) 2(N O 3)(phen)] 2, was synthesized and structurally characterized. The ESR spectr um of the complex with effective g values of 5.314, 2 47...A new quaternary mixed anion complex of gadolinium(Ⅲ), [Gd(CH 3CH 2COO) 2(N O 3)(phen)] 2, was synthesized and structurally characterized. The ESR spectr um of the complex with effective g values of 5.314, 2 473 and 1.880 in poly crys talline powder at room temperature is quite different from the U spectrum. The c oordination number of Gd 3+ is nine with a monocapped square antiprism geom etry. And the stacking effect was observed in the complex. The crystal of the co mplex belongs to triclinic with space group P 1, a=0.9626(4) n m, b=0.9732(4) nm, c=1.1758(5) nm, α=102.45(1)°, β=108.16(1) °, γ=96.68(2)°, V=1.0018(7) nm3, Z=2, D c=1.80 g·cm -3 , μ(MoKα)=33.63 mm -1, F(000)=530, GOF=1.80, R=0.023 and R w=0.027.展开更多
The hydrothermal reaction of pyridine-3,4-dicarboxylic acid(pydcH2),4,4'-bipyridine and GdCl3.6H2O yield a novel gadolinium coordination polymer {[Gd2(pydc)2(μ3-OH)2(H2O)2].H2O}n(1).The compound was chara-cterize...The hydrothermal reaction of pyridine-3,4-dicarboxylic acid(pydcH2),4,4'-bipyridine and GdCl3.6H2O yield a novel gadolinium coordination polymer {[Gd2(pydc)2(μ3-OH)2(H2O)2].H2O}n(1).The compound was chara-cterized by elemental analysis,thermal analysis,IR spectra and single-crystal X-ray structure analysis.The crystal of the Gd(Ⅲ) complex belongs to triclinic system,space group P1 with:a=0.796 25(16) nm,b=0.944 46(19) nm,c=1.262 1(3) nm,α=76.50(3)°,β=84.95(3)°,γ=83.04(3)°,Z=2,V=0.914 4(3) nm3,Dc=2.669 g.cm-1,μ=7.269 mm-1,F(000)=692,and R1=0.033 3,wR2=0.062 3.The crystal structure revealed that compound 1 has a 2D layer structure incorporating 1D Gd-O-Gd double chain,and hydrogen bonding interactions result in the former of 3D supramolecular network structure.CCDC:669079.展开更多
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 insoluble species of Gd ( Ⅲ ) in human blood plasma were investigated by computer simulation. The distribution of the Gd(Ⅲ ) species was obtained. It was found that most of the Gd( Ⅲ ) ions were bound to p...The insoluble species of Gd ( Ⅲ ) in human blood plasma were investigated by computer simulation. The distribution of the Gd(Ⅲ ) species was obtained. It was found that most of the Gd( Ⅲ ) ions were bound to phosphate to form precipitate GdPO4 at the concentration of 1. 000 10-7 mol/L and when the concentration of the Gd (Ⅲ ) increased to 3. 750 X 10-4 mol/L, in excess of the concentration of phosphate, the Gd ( Ⅲ ) ions were bound to carbonate to form another kind of precipitate, Gd2(CO3)3.展开更多
基金supported by the National Natural Science Foundation of China(No.20471056)
文摘A new cucurbit[6]uril bridsed binuclear complex {[Gd（H2O）6]2[Q6（H2O）]}C16·4H2O, where Q6 represents cucurbit[6]uril, has been synthesized and characterized by X-ray diffraction. The crystal structure shows that the complex has an extended cucurbit[6]uril-bridged structure consisting of two gadolinium（Ⅲ） ions, in which each gadolinium（Ⅲ） ion is coordinated with two neighboring carbonylic oxygen atoms of Q6 and six oxygen atoms of water molecules that leans toward one side of the portal. One disordered guest water molecule resides in the Q6 molecule cavity and occupies two different positions. Hydrogen bonds assemble the complcx to threedimensional supramolecular structure.
文摘A new quaternary mixed anion complex of gadolinium(Ⅲ), [Gd(CH 3CH 2COO) 2(N O 3)(phen)] 2, was synthesized and structurally characterized. The ESR spectr um of the complex with effective g values of 5.314, 2 473 and 1.880 in poly crys talline powder at room temperature is quite different from the U spectrum. The c oordination number of Gd 3+ is nine with a monocapped square antiprism geom etry. And the stacking effect was observed in the complex. The crystal of the co mplex belongs to triclinic with space group P 1, a=0.9626(4) n m, b=0.9732(4) nm, c=1.1758(5) nm, α=102.45(1)°, β=108.16(1) °, γ=96.68(2)°, V=1.0018(7) nm3, Z=2, D c=1.80 g·cm -3 , μ(MoKα)=33.63 mm -1, F(000)=530, GOF=1.80, R=0.023 and R w=0.027.
文摘The hydrothermal reaction of pyridine-3,4-dicarboxylic acid(pydcH2),4,4'-bipyridine and GdCl3.6H2O yield a novel gadolinium coordination polymer {[Gd2(pydc)2(μ3-OH)2(H2O)2].H2O}n(1).The compound was chara-cterized by elemental analysis,thermal analysis,IR spectra and single-crystal X-ray structure analysis.The crystal of the Gd(Ⅲ) complex belongs to triclinic system,space group P1 with:a=0.796 25(16) nm,b=0.944 46(19) nm,c=1.262 1(3) nm,α=76.50(3)°,β=84.95(3)°,γ=83.04(3)°,Z=2,V=0.914 4(3) nm3,Dc=2.669 g.cm-1,μ=7.269 mm-1,F(000)=692,and R1=0.033 3,wR2=0.062 3.The crystal structure revealed that compound 1 has a 2D layer structure incorporating 1D Gd-O-Gd double chain,and hydrogen bonding interactions result in the former of 3D supramolecular network structure.CCDC:669079.
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.
基金National Natural Science Foundation of China(Nos.29890280,29971029).
文摘The insoluble species of Gd ( Ⅲ ) in human blood plasma were investigated by computer simulation. The distribution of the Gd(Ⅲ ) species was obtained. It was found that most of the Gd( Ⅲ ) ions were bound to phosphate to form precipitate GdPO4 at the concentration of 1. 000 10-7 mol/L and when the concentration of the Gd (Ⅲ ) increased to 3. 750 X 10-4 mol/L, in excess of the concentration of phosphate, the Gd ( Ⅲ ) ions were bound to carbonate to form another kind of precipitate, Gd2(CO3)3.
文摘合成了以二氰胺(N(CN)2)为配体的镧系金属配位聚合物{[Gd(dca)2(phen)2(H2O)3]+[dca]-[phen]}m(dca=N(CN)2,phen=1,10-菲咯啉).用X射线衍射单晶分析法测定了配合物的结构,晶体为单斜晶系,属于P21/c晶群,晶胞参数为a=14.2380(11),b=16.4961(12),c=17.1927(13),晶胞数为Z=4.氢键既形成了配位聚合物的3D网络结构,又为相邻Gd金属离子之间提供了磁超交换通道,变温磁化率显示配合物为弱的反铁磁交换作用并符合外斯定律,其中外斯常数θ=-2.37 K.
