Jensen, Mark P. published the artcileAqueous Complexes for Efficient Size-based Separation of Americium from Curium, Formula: C26H36N4O8, the publication is Inorganic Chemistry (2014), 53(12), 6003-6012, database is CAplus and MEDLINE.
Complexation of the adjacent actinide ions americium(III) and curium(III) by the ligand N,N’-bis[(6-carboxy-2-pyridyl)methyl]-1,10-diaza-18-crown-6 (H2bp18c6) in aqueous solution was studied to quantify and characterize its americium/curium selectivity. Liquid-liquid extraction and spectrophotometric titration indicated the presence of both fully deprotonated and monoprotonated complexes, An(bp18c6)+ and An(Hbp18c6)2+ (An = Am or Cm), at the acidities that would be encountered when treating nuclear wastes. The stability constants of the complexes in 1 M NaNO3 determined using competitive complexation were log β101 = 15.49 ± 0.06 for Am and 14.88 ± 0.03 for Cm, indicating a reversal of the usual order of complex stability, where ligands bind the smaller CmIII ion more tightly than AmIII. The Am/Cm selectivity of bp18c62- that is defined by the ratio of the Am and Cm stability constants (β101 Am/β101 Cm = 4.1) is the largest reported so far for binary AnIII-ligand complexes. Theor. d. functional theory calculations using the B3LYP functional suggest that the ligand’s size-selectivity for larger 4f- and 5f-element cations arises from steric constraints in the crown ether ring. Enhanced 5f character in MOs involving actinide-nitrogen interactions is predicted to favor actinide(III) complexation by bp18c62- over the complexation of similarly sized lanthanide(III) cations.
Inorganic Chemistry published new progress about 1128304-86-8. 1128304-86-8 belongs to pyridine-derivatives, auxiliary class Pyridines, name is 6,6′-((1,4,10,13-Tetraoxa-7,16-diazacyclooctadecane-7,16-diyl)bis(methylene))dipicolinic acid, and the molecular formula is C26H36N4O8, Formula: C26H36N4O8.
Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem