Cooperation of Coordinative and π···π Interaction in Directing Two-fold Interpenetrated Architecture of Two Eu/Dy(III) 2-Sulfoterephthalate Complexes with 4,4′-Bipyridine.

Two novel lanthanide coordination polymers, {[Ln(stp)(bipy)(H2O)] ·(H2O)} n [Ln = Eu ( 1) and Dy ( 2)], were synthesized by hydrothermal reactions of 2-sulfoterephthalate (stp) and 4,4′-bipyridine (bipy) ligands with europium/dysprosium(III) salts. Structural analyses show that both complexes 1 and 2 are isomorphic and crystallize in the monoclinic crystal system with space group P21/ n. Complex 1 exhibits a two-dimensional grid-like structure from europium(III) ions bridged by the carboxyl and sulfonate groups of stp ligands. Notably, the stretching 4,4′-bipyridine ligands besides the 2D grid-like layers form π ···π interactions and interpenetrate into the empty voids of another adjacent layer into a twofold interpenetrated structure. Fluorescence analysis show that the emission of two complexes exhibit the characteristic peaks of lanthanide ions. [ABSTRACT FROM AUTHOR]