Two chromogenic N2S2-donor macrocycles functionalized with p-nitroazobenzene (L-1) and phenyltricyanovinyl (L-2) units were synthesized from an N-phenylated macrocyclic precursor (1) and structurally characterized by single crystal X-ray analyses. Interestingly, L-1 and L-2 exhibited excellent Hg2+ selectivity by showing the drastic metal-induced color change. from red to colorless (Delta lambda(max) = 137 - 140 nm). The sensing ability for Hg2+ with the proposed chromoionophores is due to the stable complexation with 1:1 stoichiometry (metal-to-ligand), which was,elucidated by spectrophotometry. (C) 2006 Elsevier B.V. All rights reserved.