Assembly, crystal structures and luminescent properties of the lanthanide nitrate coordination polymers with 1,5-bis{[(2′-(2-picolylaminoformyl))phenoxyl]methyl}naphthalene

A new amide type bridging ligand, 1,5-bis{[(2′-(2-picolylaminoformyl))phenoxyl]methyl}naphthalene (L), and its complexes with lanthanide ions (Ln═Sm, Eu, Gd, Tb, and Dy) have been designed and assembled. The crystal structures of {[EuL(NO3)3(CH3OH)](H2O)}n and [TbL(NO3)3(CH3OH)]n display one-dimensional (1-D) zig-zag coordination polymeric chains. At the same time, the solid state luminescent properties of the Sm, Eu, Tb, and Dy complexes were investigated at room temperature. The complexes all exhibit characteristic luminescence emissions of the central metal ions under UV light excitation. The lowest triplet state energy level (T1) of the ligand indicates that the triplet state energy level of the ligand matches better to the resonance level of Tb(III) ion than other lanthanide ions.