A tetraaza-18-crown-6 derivative (2) was synthesized by reaction of 1,10-dioxa-4,7,13,16- tetraaza-18-crown-6 (1) with 2-hydroxy-5-nitrobenzyl bromide. Its complexation properties with H^＋, Mg^2＋, Ca^2＋, Sr^2＋, Ba^2＋and Pb^2＋ were studied by the UV-vis method in H₂O-DMSO mixed solvent. The results obtained indicate that a remarkable bathochromic shift of the absorption maximum of compound 2 occurs from 319 to 426 nm upon the increase of pH, and the corresponding absorption intensity also increases. Furthermore, the binding constants for complexation of 2 with these cations increase with increasing ionic radii, and the highest binding abilities were observed for Ba^2＋and Pb^2＋.

Key words: azacrown ether, synthesis, cation, complexation