<Emphasis Type="Italic">N,N</Emphasis>’-Bis(acylvinylated) diaza-18-crown-6 ether as a lanthanide-selective macrocyclic complex-forming agent

Nucleophilic substitution in β-chlorovinyl phenyl ketone with diaza-18-crown-6 ether resulting in displacement of the chlorine atom afforded N,N’-bis(3-oxo-3-phenylpropen-1-yl)-1,10-diaza-18-crown-6 ether. The ability of the latter to form complexes with a number of metal cations was studied. However, the complex formation occurs only with the rare-earth cations Ln³⁺ and Th⁴⁺. This fact was demonstrated by UV and ¹H NMR spectroscopy of solutions, confirmed by isolations of glassy phases of composition L₃M₂(NO₃)₆ · nH₂O (M = La, Y, n ≈ 4–7), and supported by IR spectra of these phases in KBr pellets. The formation of complexes with La³⁺ and Y³⁺ leads to an increase in fluorescence intensity of the ligand. The stability constants of the 1 : 1 complexes in methanol were evaluated by spectrophotometry. These constants increase with decreasing ionic radius of the cation.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 156–160, January, 2005.