Solid complexes of rare earth picrates (pic) with the ligand 2,6-bis(benzimidazol-2-yl)pyridine (L) have been synthesized and characterized by elemental analysis, IR and electronic spectra. The crystal and molecular structures of the complex [CeL₂(pic)₂](pic)•(CH₃OH)₃ have been determined by single crystal X-ray diffraction. The crystal structure indicates that the complex crystallizes in the triclinic space group P1 with parameters: a＝1.3795(3) nm, b＝2.1292(5) nm, c＝2.5651(6) nm, α＝105.847(3)°, β＝100.150(3)°, γ＝107.893(3)°, Z＝2, R＝0.0519, wR＝0.1255. The crystal consists of two similar but independent molecules in the asymmetric unit and the Ce(III) ion coordinated toward ten donor atoms, six of which belong to the nitrogen atoms of two tridentate ligands and four oxygen atoms from two bidentate picrates. The coordination polyhedron around Ce^3＋ is a distorted square antiprism, and the two independent molecules are connected by π-π stacking interactions to form a noncentrosymmetric dimer. The crystal structure is built of a packing of these dimers via intermolecular hydrogen bonding to yield an infinite three-dimensional supramolecular network. At room temperature, under UV light excitation the Eu(III) complex exhibited characteristic emission of the central metal ions both in solid state and in solutions.

Key words: 2,6-bis(benzimidazol-2-yl)pyridine, rare earth picrates complex, synthesis, crystal structure, luminescent property