Complex formation between azacrown derivatives of dibenzylidenecyclopentanone and alkali-earth metal ions

The complex formation of 2,5-bis[4-(1,7,10,13-tetraoxa-4-azacyctopentadec-4-yl)benzyl-idene]cyclopentanone and several model compounds, prospective metal-sensitive fluorescent probes, with Mg2+, Ca2+, and Ba2+ ions in acetonitrile was studied. The azacrown derivatives of dibenzylidenecyclopentanone have two complex formation centers, azacrown cycle and carbonyl group. The sequence of binding to these sites is different for different ions, The efficient ejection of the Ca2+ and Ba2+ ions from their complexes with azacoronands was observed in the excited state, whereas in the case of the Mg2+ ion, this process occurred only partially.