Three novel dinuclear ZnII complexes of phenol-based compartmental macrocyclic ligands have been synthesized and characterized by routine physicochemical techniques as well as by X-ray single-crystal structure analysis. The dinuclear macrocyclic complexes 1, 2, and 3 were obtained through a 1:2 condensation reaction of 2,6-diformyl-4-methylphenol and N-(hydroxyalkyl) ethylenediamine (L1, L2, and L3, respectively) in the presence of zinc(II) acetate, followed by the addition of thiocyanate anion [L1 = N-(2-hydroxyethyl)ethylenediamine, L2 = N-(3-hydroxypropyl)ethylenediamine, and L3 = N-(2-hydroxypropyl) ethylenediamine]. The synthesized 18-membered macrocycles are noted to be structurally unique, and their formation proceeds with the generation of two oxazolidine side rings in complexes 1 and 3 and two oxazine side rings in 2, along with the creation of four new chiral centers in each case. Complexes 1 and 2 are characterized by a butterfly-like arrangement with the SCN ligands situated on the same side with respect to the Zn2O2 moiety, whereas the centrosymmetric complex 3 exhibits a stepped arrangement with parallel methyl-phenoxy fragments (spaced at ca. 1.5 Å) and trans located SCN ligands with respect to the Zn2O2 core. The formation of these unusual macrocycles is considered to be zinc-mediated. Preliminary studies with the complexes show that all of them exhibit an inhibitory effect, on the cell proliferation of human stomach cancer cell line AGS, though with different degrees, where complex 3 shows the highest efficiency. © 2009 American Chemical Society.