化学
位阻效应
选择性
溶剂
萃取(化学)
溶剂萃取
溶剂效应
有机化学
组合化学
催化作用
作者
Petr I. Matveev,Pin‐Wen Huang,Anna A. Kirsanova,Ivan V. Ananyev,Tsagana B. Sumyanova,Anastasia V. Kharcheva,Evgenii Yu. Khvorostinin,В. Г. Петров,Wenjing Shi,Stepan N. Kalmykov,Nataliya E. Borisova
出处
期刊:Inorganic Chemistry
[American Chemical Society]
日期:2021-09-21
卷期号:60 (19): 14563-14581
被引量:20
标识
DOI:10.1021/acs.inorgchem.1c01432
摘要
Hybrid donor extractants are a promising class of compounds for the separation of trivalent actinides and lanthanides. Here, we investigated a series of sterically loaded diphosphonate ligands based on bipyridine (BiPy-PO-iPr and BiPy-PO-cHex) and phenanthroline (Phen-PO-iPr and Phen-PO-cHex). We studied their complex formation with nitrates of trivalent f-elements in solvent extraction systems (Am and Eu) and homogeneous acetonitrile solutions (Nd, Eu, and Lu). Phenanthroline extractants demonstrated the highest efficiency and selectivity [SF(Am/Eu) up to 14] toward Am(III) extraction from nitric acid solutions among all of the studied diphosphonates of N-heterocycles. The binding constants established by UV–vis titration also indicated stronger binding of sterically impaired diphosphonates compared to the primary substituted diphosphonates. NMR titration and slope analysis during solvent extraction showed the formation of 2:1 complexes at high concentrations (>10–3 mol/L) for phenanthroline-based ligands. According to UV–vis titrations at low concentrations (10–5–10–6 mol/L), the phenanthroline-based ligands formed 1:1 complexes. Bipyridine-based ligands formed 1:1 complexes regardless of the ligand concentration. Luminescence titrations revealed that the quantum yields of the complexes with Eu(III) were 81 ± 8% (BiPy-PO-iPr) and 93 ± 9% (Phen-PO-iPr). Single crystals of the structures [Lu(μ2,κ4-(iPrO)2P(O)Phen(O)2(OiPr))(NO3)2]2 and Eu(Phen-PO-iPr)(NO3)3 were obtained by chemical synthesis with the Phen-PO-iPr ligand. X-ray diffraction studies revealed a closer contact of the f-element with the aromatic N atoms in the case of sterically loaded P═O ligands compared with sterically deficient ligands. Density functional theory calculations allowed us to rationalize the observed selectivity trends in terms of the bond length, Mayer bond order, and preorganization energy.
科研通智能强力驱动
Strongly Powered by AbleSci AI