Abstract: EPR spectra of three new quaternary gadolinium complexes(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.

Key words: Gadolinium(Ⅲ), Quaternary mixed anion complex, EPR spectrum