| Abstract
| - Two new ligands 7-anthracenylmethyl-13-methylpyridyl-1,4,10-trioxa-7,13-diazacyclopentadecane (L4) and 7-anthracenylmethyl-13-(2,2-dimethyl-2-hydroxyethyl)-1,4,10-trioxa-7,13-diazacyclopentadecane (L5) have been synthesizedand characterized. Both derive from 7-anthracenylmethyl-1,4,10-trioxa-7,13-diazacyclopentadecane (L3) and differfor having a differently functionalized pendant arm covalently attached to the remaining secondary nitrogen donorof the macrocyclic framework. The protonation and coordination behavior of L4, L5, and the unbranched L3 withmetal ions have been studied in MeCN/H2O (1:1 v/v, 298.1 K, I = 0.1 M) using potentiometric methods. Thecrystal structures of L3, [(H2L3)(HL3)](ClO4)3, and the complex [CdL3(NO3)2] have been determined by single-crystalX-ray methods. The fluorescent behavior of L3−L5 in the presence of CuII, ZnII, CdII, HgII, and PbII has been studiedas a function of pH in MeCN/H2O (1:1 v/v). The presence of CuII, HgII, or PbII does not affect the fluorescentbehavior observed for the three free ligands upon changing the pH. Interestingly, the fluorescent emission of L3and L5 is selectively enhanced only in the presence of CdII at basic pH. The same effect is observed for L4 in thepresence of CdII or ZnII at about pH 7.
- The effect, in terms of metal ion substrate-specific response, of the coordinating pendant arms attached to L3 has been studied by potentiometric and spectrofluorimetric measurements as function of pH in MeCN/H2O (1:1 v/v).
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