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
一、概述电子顺磁共振技术(EPR或ESR)已有40余年历史,它在催化研究中的应用可以追溯到30年前。早期的EPR在催化研究领域中的重要进展可以列举SiO_2上吸附H的检测,硅铝催化剂上芳烃自由基的检测以及对一系列氧化物上O_2^-自由基的研究。...一、概述电子顺磁共振技术(EPR或ESR)已有40余年历史,它在催化研究中的应用可以追溯到30年前。早期的EPR在催化研究领域中的重要进展可以列举SiO_2上吸附H的检测,硅铝催化剂上芳烃自由基的检测以及对一系列氧化物上O_2^-自由基的研究。在这一领域中,Lunsford, Che, Tenth和Kazansky等做了大量开拓性工作。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.
文摘一、概述电子顺磁共振技术(EPR或ESR)已有40余年历史,它在催化研究中的应用可以追溯到30年前。早期的EPR在催化研究领域中的重要进展可以列举SiO_2上吸附H的检测,硅铝催化剂上芳烃自由基的检测以及对一系列氧化物上O_2^-自由基的研究。在这一领域中,Lunsford, Che, Tenth和Kazansky等做了大量开拓性工作。
