Novel hexanuclear zinc(II) complex of 1,3,5-benzenemethyltriiminodiacetate

A novel cyclic dimer of a trinuclear zinc complex, {[Zn3(bmtac)(H2O)8] · 6H2O}2, with very long Zn–Zn distances, was synthesized in aqueous solution by adopting a new type of flexible multicarboxylate ligand, H6bmtac (H6bmtac = 1,3,5-benzenemethyltriiminodiacetic acid). The X-ray crystal structure of {[Zn3(bmtac)(H2O)8] · 6H2O}2 reveals that all Zn(II) ions are six-coordinated with octahedral geometry. The dimer as basic building units assembled into a three-dimensional supramolecular framework through the multiple intermolecular O–H⋯O hydrogen bonds interactions. The complex shows a blue fluorescent emission band at 428 nm as the result of the intraligand (π–π∗) fluorescent emission.