Multiple-Frequency and Variable-Temperature EPR Study of Gadolinium(III) Complexes with Polyaminocarboxylates: Analysis and Comparison of the Magnetically Dilute Powder and the Frozen-Solution Spectra
作者:Meriem Benmelouka、Johan Vanâ
Tol、Alain Borel、Saritha Nellutla、Marc Port、Lothar Helm、Louis-Claude Brunel、Andréâ
E. Merbach
DOI:10.1002/hlca.200900117
日期:2009.11
An electron paramagnetic resonance (EPR) study of glasses and magnetically dilute powders of [Gd(DTPA)(H2O)]2−, [Gd(DOTA)(H2O)]−, and macromolecular gadolinate(1−) complexes P792 was carried out at the X‐ and Q‐bands and at 240 GHz (DTPA=diethylenetriaminepentaacetato; DOTA=1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetraacetato). The results show that the zero‐field splitting (ZFS) parameters for these
对玻璃和[Gd(DTPA)(H 2 O)] 2-,[Gd(DOTA)(H 2 O)] -和大分子ado(1-)配合物的磁性稀释粉末的电子顺磁共振(EPR)研究P792在X和Q频段以及240 GHz(DTPA =二亚乙基三胺五乙酸; DOTA = 1,4,7,10-四氮杂环十二烷-1,4,7,10-四乙酸)下进行。结果表明,与冷冻水溶液相比,粉末中这些配合物的零场分裂(ZFS)参数差异很大。在多个配合物中,轴向分量D的符号反转观察到零场分裂的“ 0”,表明明显的结构变化。与预期相反,通过冻干获得的粉末样品无法更精确地确定静态ZFS参数。与从粉末中获得的结果相比,在玻璃中获得的结果与水溶液中的电子自旋弛豫问题更相关。