Crystal Structure and Luminescent Properties of Complex [Eu 0.5 Gd 0.5 (C 12 H 9 O 2 ) 2 (C 12 H 8 N 2 ) 2 (H 2 O) 2 ]•(C 12 H 9 O 2 )•H 2 O

One new rare-earth ternary complex with 1-naphthylacetic acid and 1,10-phenanthroline, [Eu0.5Gd0.5(C12H9O2)2(C12H8N2)2(H2O)2]•(C12H9O2)•H2O were synthesized. The structures were established by single crystal X-ray diffraction. The europium (gadolinium) ion is eight-coordinate with four oxygen and four nitrogen atoms forming a coordination polyhedron best describable as a distorted dodecahedral. The luminescence spectra of the complex in a solution of DMF were studied. The complex display characteristic Eu(III)-originated red emission as a sharp band at 617 nm. It is concluded that the metal-centered red emission is promoted by the ligand-assisted energy transfer.