Understanding the Effect of the Electron Spin Relaxation on the Relaxivities of Mn(II) Complexes with Triazacyclononane Derivatives
作者:Rocío Uzal-Varela、Laura Valencia、Daniela Lalli、Marcelino Maneiro、David Esteban-Gómez、Carlos Platas-Iglesias、Mauro Botta、Aurora Rodríguez-Rodríguez
DOI:10.1021/acs.inorgchem.1c02057
日期:2021.10.18
polyhedron being close to a trigonal prism. The relaxivities of all complexes at 20 MHz and 25 °C (1.1–1.3 mM–1 s–1) are typical of systems that lack water molecules coordinated to the metal ion. The nuclear magnetic relaxation profiles evidence significant differences in the relaxivities of the complexes at low fields (<1 MHz), which are associated with different spin relaxation rates. The zero field
研究顺磁性 Mn(II) 复合物诱导的水1 H 核的弛豫对于了解控制用于诊断磁共振成像 (MRI) 的造影剂效率的机制很重要。在此,设计了一系列包含不同悬臂的潜在六齿三氮杂环壬烷 (TACN) 衍生物,通过结合1 H NMR 弛豫和理论计算来探索相应 Mn(II) 配合物中电子自旋的弛豫。这些配体包括 1,4,7-三氮杂环壬烷-1,4,7-三乙酸 (H 3 NOTA) 和三个衍生物,其中乙酸基被磺酰胺 (H 3 NO2ASAm)、酰胺 (H 2 NO2AM) 或吡啶基(H2 NO2APy) 吊坠。还研究了包含三个丙酸悬垂臂(H 3 NOTPrA)的 H 3 NOTA类似物。含有两个乙酸酯基团和一个磺酰胺悬臂 [Mn(NO2ASAm)] -的衍生物的 X 射线结构证明了配体与金属离子的六配位,配位多面体接近三棱柱。所有配合物在 20 MHz 和 25 °C (1.1–1.3 mM –1 s –1)