Synthesis, structural and extraction studies of new bifunctional ligand with uranium

A new bifunctional ligand system containing N-oxide and carbamoyl donor groups has been synthesized and coordination chemistry with uranyl nitrate has been explored. This new ligand system forms 1:1 complex with uranium. The extraction studies show appreciable extraction of tetra and hexavalent actinides from HNO3 medium. [Display omitted] •A new bifunctinal ligand system for actinides extraction having NO and CO donor has been reported.•Single crystal-X ray structure of one of the uranyl complex shows 1:1 ligand to metal ratio.•Stoichiometry of the extracted uranyl complex has been established by solvent extraction studies. A new bifunctional ligand system (N,N-dialkyl carbamoyl methyl) (2-pyridyl-N-Oxide) sulfide C5H4NOSCH2CONR2, (where R=isopropyl (L1), isobutyl (L2) and butyl (L3) and octyl (L4)) have been synthesized. The coordination chemistry of this ligand system with UO2(NO3)2·6H2O has been carried out. All the ligands and complexes were characterized by CHN, IR and NMR techniques. Single crystal X-ray study of one of the complexes (2) shows that the uranium atom is surrounded by eight oxygen atoms in a hexagonal-bi-pyramidal geometry. Ligand is bonded to metal through carbamoyl and N-oxide groups in a chelating fashion. Thermogravimetric studies of the complexes shows that the ligands are completely incinerable. Extraction studies of the actinides with ligand L4 show that this new bifunctional ligand has very good distribution ratio (D) values for tetravalent and hexavalent actinides ions from nitric acid medium.