Three new gallium complexes formulated as [Ga(PDA)2][Ga(H2O)(PDA)(phen)]·4H2O(1),[Ga(PDA) 2 ]·(H2IN)·2H2O(2) and [Ga(OH)(PDA)(H2O)] 2(3)(H2PDA=pyridine-2,6-dicarboxylic acid;phen=1,10-phenanthroline;HIN=isonicotinic acid) have been synthesized under hydrothermal conditions.In the mixed-ligand system of complex 1,PDA2 and phen are connected to the central Ga 3+ cation as tri-and bi-dentate ligands,respectively.In complex 2,each Ga 3+ cation is six-coordinated by two PDA2 anions octahedrally.Complex 3 shows a binuclear structure,with the bond distance of Ga1― Ga2 being 0.30061(3) nm.The 3D supramolecular structures of the three complexes are constructed via hydrogen bonds and aromatic π-π packing interactions.All the three complexes exhibit intense blue emission at room temperature in the solid state,which are attributed to π*-π transition centered on the ligands.