Planar tetrameric metal cluster formation at room temperature induced by π⋯π interactions: 3D supramolecular host containing 1D channel filled with solvent methanol

A novel tetrameric metal cluster, [La2(phen)3(2,3-pdc)(NO3)4(H2O)]2·(CH3OH)2 (2,3-pdcH2 = pyridine-2,3-dicarboxylic acid, phen = 1,10-phenanthroline), have been synthesized at room temperature from water–methanol mixture by mixing the reactants in stoichiometric ratio. 2,3-Pdc and their π⋯π interactions played a vital role on the construction of the core. The auxiliary ligand, phen, which blocked the outermost periphery of the molecule and their hydrophobic π⋯π interactions facilitate the formation of the tetrameric metal clusters. The tetrameric metal clusters are connected by supramolecular interactions to form 3D supramolecular metal organic host (MOSH) producing supramolecular channels along a-axis. These supramolecular channels are filled up by solvent methanol molecules. The luminescent investigations reveal that cluster complex exhibits strong blue emission.