Eu(NO₃)₃•4H₂O has reacted with 2-oxopropionic acid salicyloyl hydrazone (C₁₀H₁₀N₂O₄) and 2,2'-bipyridyl (C₁₀H₈N₂, bipy) to obtain a yellow prismatic crystal of the complex [Eu(C₁₀H₉N₂O₄)- (C₁₀H₈N₂O₄)(H₂O)₃]•0.5bipy•3H₂O for the first time in H₂O-C₂H₅OH mixed solvent. The compound crystallized in the triclinic system with space group P-1 and parameters a＝0.93392(16) nm, b＝1.3100(2) nm, c＝1.3895(2) nm, α＝97.205(3)°, β＝105.411(2)°, γ＝106.364(2)°, V＝15.35(2) nm³, Z＝2, μ＝2.118 mm^－1, D_c＝1.686 Mg/m³, F(000)＝786, R＝0.0116, wR＝0.0507 and GOF＝0.995. In the structure, europium atom is 9-coordinated by carboxyl O and acyl O atoms and azomethine N atom of two tridentate C₁₀H₁₀N₂O₄ ligands negative univalent and bivalent and three water molecules to form two stable five-membered rings sharing one side in ketone form. The coordination polyhedron around Eu^3＋ was described as a single cap square antiprism. In the crystal cell, there are one free bipy and three water molecules connected with 2-oxopropionic acid salicyloyl hydrazone and coordinated water molecule by hydrogen bonds. The complex formed a three-dimensional super molecule in space through hydrogen bonds. The test of luminescence performance of the complex has shown it has good fluorescence property.

Key words: europium(III) complex, 2-oxopropionic acid salicyloyl hydrazone, 2,2-bipyridyl, crystal structure, fluorescence