A Self-Assembled Zn(II)-Nd(III) Heterohexanuclear Dimer Based on a Hexadentate N(2)O(4)-Type Ligand and Terephthalic Acid: Synthesis, Structure, and Fluorescence Properties

A self-assembled Zn(II)-Nd(III) heterohexanuclear coordination compound [Zn(4)Nd(2)(L)(4)(bdc)(2)]·2NO(3) based on a hexadentate Salamo-like chelating ligand (H(2)L = 1,2-bis(3-methoxysalicylideneaminooxy)ethane]) and H(2)bdc (H(2)bdc = terephthalic acid) has been synthesized and characterized by elemental analyses, IR and UV/Vis spectra, and X-ray crystallography. Two crystallographically equivalent [Zn(2)Nd(L)(2)] moieties lie in the inversion center linked by two (bdc)(2−) ligands leading to a heterohexanuclear dimer in which the carboxylato group bridges the Zn(II) and Nd(III) atoms. The heteropolynuclear 3d-4f coordination compound includes four Zn(II) atoms, two Nd(III) atoms, four completely deprotonated (L)(2−) units, two fully deprotonated (bdc)(2−) units, and two crystalling nitrate ions. All of the Zn(II) atoms in the Zn(II)-Nd(III) coordination compound possess trigonal bipyramidal geometries and the Nd(III) atoms possess distorted bicapped square antiprism coordination arrangements. In addition, the fluorescence properties of the ligand and the Zn(II)-Nd(III) coordination compound were investigated.