1D lanthanide coordination polymers containing biphosphonate ligand: Synthesis, structures and luminescence properties

Six novel lanthanide complexes [LnL(Phen)Cl-3] n (1-6) (Ln = Sm, Eu, Gd, Tb, Dy, Ho) (L = tetraethyl ethylenebisphosphonate, Phen = 1,10-phenanthroline) have been synthesized through a simple one-pot reaction. Complexes 1-6 are of 1D infinite chain structure. The CeH center dot center dot center dot pi interactions and the bridging action of L ligand lead to the formation of 3D network structures for 1-6. Emission spectra of complexes 1, 2, 4 and 5 show characteristic emission peaks of Sm3+, Eu3+, Tb3+ and Dy3+, respectively. Quantum yield of 2 is up to 37% while that of 4 reaches 31% in solid state, so they can be used as potential luminescent materials.