IJCLab CNRS-IN2P3, Université Paris-Saclay, 91405 Orsay, France.
Institute of Nuclear and New Energy Technology, Tsinghua University, 100084 Beijing, China.
Inorg Chem. 2021 Feb 15;60(4):2149-2159. doi: 10.1021/acs.inorgchem.0c02145. Epub 2021 Feb 1.
The development of actinide decorporation agents with high complexation affinity, high tissue specificity, and low biological toxicity is of vital importance for the sustained and healthy development of nuclear energy. After accidental actinide intake, sequestration by chelation therapy to reduce acute damage is considered as the most effective method. In this work, a series of bis- and tetra-phosphonated pyridine ligands have been designed, synthesized, and characterized for uranyl (UO) decorporation. Owing to the absorption of the ligand and the luminescence of the uranyl ion, UV-vis spectroscopy and time-resolved laser-induced fluorescence spectroscopy (TRLFS) were used to probe complexation and structure variation of the complexes formed by the ligands with uranyl. Density functional theory (DFT) calculations and X-ray absorption fine structure (XAFS) spectroscopy on uranyl-ligand complexes revealed the coordination geometry around the uranyl center at pH 3 and 7.4. High affinity constants (log ∼17) toward the uranyl ion were determined by displacement titration. A preliminary chelation study proves that bis-phosphonated pyridine ligands can remove uranium from calmodulin (CaM) at a low dose and in the short term, which supports further uranyl decorporation applications of these ligands.
发展具有高络合亲和力、高组织特异性和低生物毒性的锕系元素去除剂对于核能的持续健康发展至关重要。在意外摄入锕系元素后，螯合疗法通过螯合来减少急性损伤被认为是最有效的方法。在这项工作中，设计、合成并表征了一系列双膦酸和四膦酸吡啶配体，用于铀（UO）的去除。由于配体的吸收和铀离子的发光，使用紫外可见光谱和时间分辨激光诱导荧光光谱（TRLFS）来探测配体与铀形成的配合物的络合和结构变化。铀-配体配合物的密度泛函理论（DFT）计算和 X 射线吸收精细结构（XAFS）光谱揭示了在 pH 3 和 7.4 下铀中心周围的配位几何形状。通过置换滴定确定了对铀离子的高亲和常数（log ∼17）。初步的螯合研究证明，双膦酸吡啶配体能在低剂量和短时间内从钙调蛋白（CaM）中去除铀，这支持了这些配体在进一步铀去除应用中的研究。
