ИСТИНА

Using simple nucleophilic substitution reactions, aza- and diazacrown ethers were modified with dansyl and 7-methoxycoumarine fluorophores while the introduction of the quinolinyl fluorophores was achieved using Pd(0)-catalyzed heteroarylation of aza- and diazacrown ethers with 6-bromoquinoline. The synthesized ligands were tested in the coordination of 22 metals cations taken as corresponding perchlorates or nitrates: Li(I), Na(I), K(I), Mg(II), Ca(II), Ba(II), Al(III), Mn(II), Cr(III), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Pb(II), Hg(II), Ag(I), Ga(III), In(III), Y(III), Sr(III) using fluorescence spectroscopy. The emission of the dansyl derivative of 1-aza-15-crown-5 ether was quenched by Cu(II), Cd(II), Co(II), Cr(III), Ba(II), Pb(II), Al(III), Ga(III), while with In(III) a new emission band emerged with hypsochromic shift of the maximum. Didansyl derivative of the diaza-18-crown-6 ether was more selective as only excess of Co(II) slightly quenched the emission and Cu(II) (5 equiv.) diminished it 3 times. With the quinolinyl derivatives of aza- and diazacrown ethers no good selectivity was observed in all cases, but the dependence of the emission quenching on the structure of the ligand was unique in each case. The emission at 525 nm of 7-methoxycoumarine derivative of 1-aza-15-crown-5 ether diminished in the presence of Ag(I), Cr(III), Co(II) while in the presence of Li(I) it increased substantially. Some metals like Pb(II), Cu(II), Cd(II), Zn(II), Mn(II), Y(III), Mg(II), Ca(II), Ba(II) led to a new strong emission with maximum at 410 nm.