Two novel 3D lanthanide supramolecular coordination polymers constructed from paddle wheel SBUs and hydrogen bonding: synthesis, structures and properties

Abstract

Two novel 3D lanthanide supramolecular coordination polymers, formulated as {[Ln₂(PIP)₂(HPIP)(HCO₂)(H₂O)₂]·H₂O} (Ln = Tb 1, Eu 2 and H₂PIP = 5-(pyridine-4-yl)isophthalic acid) have been solvothermally synthesized through in situ generation of formate anions. Single-crystal X-ray diffraction studies reveal that they are isomorphic and both display a 2D layered structure constructed by lanthanide paddle wheel SBUs and expanded by hydrogen bond interactions into a 3D-supramolecular architecture. Temperature dependent luminescent measurements show that compounds 1 and 2 exhibit bright green and red fluorescence at 10 K with long lifetimes of 1.00 and 1.19 ms and moderate quantum yields of 44.66% (at 310 nm) and 26.75% (at 338 nm), respectively. In addition, an anti-ferromagnetic interaction between the Tb(III) ions is observed in 1.