钆(Ⅲ)混合阴离子配合物的电子顺磁共振谱

稀土离子Gd^3 和Eu^2 体系在室温下可得到清晰的电子顺磁共振（EPR）图谱。由谱图可获取顺磁离子的自旋态、配位结构、晶体场强和电子能级等重要信息。Gd(Ⅲ）作为顺磁性的结构探针，在研究蛋白质结构和金属离子间的相互作用方面已得到应用。但至今对Gd(Ⅲ）配合物EPR波谱研究报导不多，仅限于三元配合物和玻璃质固体掺杂Gd(Ⅲ）的波谱研究，且Gd(Ⅲ）波谱均具“U”谱特征(g-6.0,2.8和2.0）。本文研究了三种新的Gd(Ⅲ）四元配合物在不同条件下的EPR谱，得到一些新 的结果，并利用自旋Hamilton理论解释了不同类型的图谱特征。

EPR Properties of NovelQuaternary Mixed Anion Complexes of Gadolinium(

Abstract EPR spectra of three new quaternary gadoliniumcomplexes(I： [Gd(C6H5COO)2(NO3)(bipy)]2,Ⅱ ： [Gd(m-CH3C6H4COO)2(NO3)(phen)]2 and Ⅲ ： [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 complex Ⅲ was first observed in polycrystalline powder at 77K and three types of EPR spectra for three complexes,symmetry resonance spectrum for the complex Ⅱ,U spectrum for the complex Ⅲ ,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 parameters λ′of the complexes I and Ⅲ were estimated.