Luminescent and Magnetic Cyano-Bridged Coordination Polymers Containing 4d−4f Ions: Toward Multifunctional Materials

A new family of cyano-bridged coordination polymers Ln(H2O)5[M(CN)8] (Ln = Eu, Tb, Sm, Gd; M = Mo, W) were obtained and characterized by X-ray diffraction, photoluminescence spectroscopy, and magnetic analyses. These compounds are isomorphous and crystallize in the tetragonal system P4/nmm, forming two-dimensional gridlike networks. The Eu- and Tb-containing coordination polymers are room-temperature optically active emitters displaying the characteristic 5D0 → 7F0-4 (Eu3+) and 5D4 → 7F6−2 (Tb3+) transitions. All of the coordination polymers except Eu(H2O)5[M(CN)8] present long-range magnetic ordering at low temperatures. The coexistence of luminescence with ferromagnetic ordering for Tb(H2O)5[M(CN)8] (M = Mo, W) suggests that these compounds may be considered as bifunctional magneto-luminescent coordination polymers exhibiting diverse physical responses when subjected to various external stimuli.