Macro-, micro-, nano- and crystal structures of a homodinuclear complex [NH3(CH2)(3)NH3](2){Na-2[(C6H4O2)(2)](C6H4O2H)(2)}

A homodinuclear complex (NH3CH2CH2CH2NH3)(2)[Na-2[(C6H4O2)(2)](C6H4O2H)(2)} (1) has been synthesized by a solution-based self-assembly route. It crystallized in monoclinic system with space group P2(1)/c. Every sodium ion coordinates in a tetragonal prism fashion with two 0 atoms of a terminal chelating catecholate ligand and three 0 atoms from two bridging catecholate ligands. Two neighboring NaO5 tetragonal prisms are edge-shared and centrosymmetric with regard to the inversion center to form a binuclear cluster (Na-2[(C6H4O2)(2)](C6H4OOH)(2)}(4-) anion. The complex anions were aligned parallelly by pi-pi interaction and linked with the protonated 1,3-propylenediamine through hydrogen bonds which were assembled into a multi-lamellar structure with channels. The crystal exhibits rectangular geometry with an interior triangle hollow structure under optical microscopy. And the scanning electron microscopy (SEM) indicates that the wall of the tubes shows multi-lamella morphologies. Further, the transmission electron microscopy (TEM) reveals that the crystal is composed of multi-lamellar nano-tubes with diameters less than 100 nm. The molecular structure of the complex was compared with that of its isomer complex 2.