title: CMPO-calix[4]arenes with spacer containing intramolecular hydrogen bonding: effect of local rigidification on solvent extraction toward f-block elements.
abstract: To understand intramolecular hydrogen bonding in effecting liquid-liquid extraction behavior of CMPO-calixarenes, three CMPO-modified calix[4]arenes (CMPO-CA) 5a-5c with hydrogen-bonded spacer were designed and synthesized. The impact of spacer rotation that is hindered by introduction of intramolecular hydrogen bonding upon extraction of La(3+), Eu(3+), Yb(3+), Th(4+), and UO2(2+) has been examined. The results show that 5b and 5c containing only one hydrogen bond with a less hindered rotation spacer extract La(3+) more efficiently than 5a containing two hydrogen bonds with a more hindered rotation spacer, demonstrating the importance of local rigidification of spacer in the design of extractants in influencing the coordination environment. The large difference in extractability between La(3+) and Yb(3+) (or Eu(3+)) by 5b (or 5c), and the small difference by 5a, suggests intramolecular hydrogen bonding do exert pronounced influence upon selective extraction of light and heavy lanthanides. Log-log plot analysis indicates a 1:1, 2:1 and 1:1 stoichiometry (ligand/metal) for the extracted complex formed between 5b and La(3+), Th(4+), UO2(2+), respectively. Additionally, their corresponding acyclic analogs 7a-7c exhibit negligible extraction toward these metal ions. These results reveal the possibility of selective extraction via tuning local chelating surroundings of CMPO-CA by aid of intramolecular hydrogen bonding.
authors.affiliation: Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, College of Chemistry, Sichuan University, Chengdu 610064, China.
authors.forename: Hongzhu
authors.initials: H
authors.lastname: Chu
authors.affiliation: Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, College of Chemistry, Sichuan University, Chengdu 610064, China.
authors.forename: Lutao
authors.initials: L
authors.lastname: He
authors.affiliation: Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, College of Chemistry, Sichuan University, Chengdu 610064, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Jiang
authors.affiliation: Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, College of Chemistry, Sichuan University, Chengdu 610064, China.
authors.forename: Yuyu
authors.initials: Y
authors.lastname: Fang
authors.affiliation: Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, College of Chemistry, Sichuan University, Chengdu 610064, China.
authors.forename: Yiming
authors.initials: Y
authors.lastname: Jia
authors.affiliation: Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, College of Chemistry, Sichuan University, Chengdu 610064, China.
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Yuan
authors.affiliation: Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, College of Chemistry, Sichuan University, Chengdu 610064, China.
authors.forename: Shuliang
authors.initials: S
authors.lastname: Zou
authors.affiliation: Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, College of Chemistry, Sichuan University, Chengdu 610064, China.
authors.forename: Xianghui
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, College of Chemistry, Sichuan University, Chengdu 610064, China. Electronic address: wfeng9510@scu.edu.cn.
authors.forename: Wen
authors.initials: W
authors.lastname: Feng
authors.affiliation: Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, College of Chemistry, Sichuan University, Chengdu 610064, China.
authors.forename: Yuanyou
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, College of Chemistry, Sichuan University, Chengdu 610064, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Liu
authors.affiliation: Institute of Nuclear Physics and Chemistry, CAEP, Mianyang 621900, China.
authors.forename: Shunzhong
authors.initials: S
authors.lastname: Luo
authors.affiliation: Institute of Nuclear Physics and Chemistry, CAEP, Mianyang 621900, China.
authors.forename: Yanqiu
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Institute of Nuclear Physics and Chemistry, CAEP, Mianyang 621900, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Yang
authors.affiliation: Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, College of Chemistry, Sichuan University, Chengdu 610064, China. Electronic address: lhyuan@scu.edu.cn.
authors.forename: Lihua
authors.initials: L
authors.lastname: Yuan
mesh_terms: D008671:Actinoid Series Elements / Q000302:isolation & purification*; D047250:Calixarenes / Q000737:chemistry*; D002221:Carbamyl Phosphate / Q000737:chemistry*; D006860:Hydrogen Bonding; D028581:Lanthanoid Series Elements / Q000302:isolation & purification*; D059625:Liquid-Liquid Extraction
chemical_list: D008671:Actinoid Series Elements; D028581:Lanthanoid Series Elements; D047250:Calixarenes; D002221:Carbamyl Phosphate
keywords: CMPO-calixarene; Hydrogen bonding; Solvent extraction; f-Block elements