Gadolinium Complexes of Highly Rigid, Open-Chain Ligands Containing a Cyclobutane Ring in the Backbone: Decreasing Ligand Denticity Might Enhance Kinetic Inertness
作者:Oriol Porcar-Tost、José A. Olivares、Agnès Pallier、David Esteban-Gómez、Ona Illa、Carlos Platas-Iglesias、Éva Tóth、Rosa M. Ortuño
DOI:10.1021/acs.inorgchem.9b02044
日期:2019.10.7
explore novel ligand scaffolds for stable and inert lanthanide complexation in magnetic resonance imaging contrast agent research, three chiral ligands containing a highly rigid (1S,2S)-1,2-cyclobutanediamine spacer and different number of acetate and picolinate groups were efficiently synthesized. Potentiometric studies show comparable thermodynamic stability for the Gd3+ complexes formed with either
为了在磁共振成像造影剂研究中探索用于稳定和惰性镧系元素络合的新型配体支架,三个手性配体包含高刚性(1 S,2 S)-1,2-环丁二胺间隔基和不同数量的乙酸盐和吡啶甲酸组被有效地合成。电位研究表明,对于由带有两个乙酸盐或两个吡啶甲酸基团的八齿(L3)4-或带有一个吡啶甲酸和三个乙酸酯基团的七齿(L2)4-类似物形成的Gd 3+络合物具有相当的热力学稳定性(log K GdL = [Gd(L2)] -和[Gd(L3)] - 17.41和18.00-, 分别)。相比之下,它们的解离动力学非常不同:与二水合的[Gd(L2)相比,由于质子化吡啶甲酸功能的显着动力学活性,一水合的[Gd(L3)] -更加不稳定。 )] -。这是一个不常见的例子,其中配体密度的降低导致动力学惰性的显着提高。另一个有趣的观察结果是,刚性配体主链诱导了自发解离对整个分解过程的异常强大的贡献。由于存在两个内层水分子,[Gd(L2)]