Synthesis, crystal structures and properties of lanthanide-organic frameworks based benzene carboxylates with two/three-dimensional structure

A series of lanthanide coordination polymers, {[Dy3(1,3-BDC)4(NO3)(phen)3]·2H2O}n (1), {[Dy2(1,3-BDC)3(H2O)2]·H2O}n (2), {[Ln4(1,3-BDC)6(DMF)(H2O)4]·DMF·2H2O}n (Ln=Tb (3), Ho (4), Er (5), 1,3-H2BDC=1,3-benzenedicarboxylate, phen=1,10-phenanthroline, DMF=N,N-dimethylformamide), have been synthesized and characterized. In coordination polymer 1, each Dy3+ ion is connected to its neighboring Dy3+ ion through bridging carboxyl oxygen atoms of the 1,3-BDC2− ligands to form a new three-dimensional open-framework structure which the Schläfli symbol of {64·82}2{66}. In coordination polymer 2, center metal dysprosium ions are interlaced and connected through bridging carboxyl oxygen atoms to form an infinite helix chain. Two helix chains are linked through the 1,3-BDC2− ligand to give rise to the two-dimensional layered structure. Coordination polymers 3–5 are isomorphous, which displays a (3,4)-connected net with the point symbol of {42·63·8}{42·6}. The solid-state photoluminescence properties and lifetimes of the Dy (1 and 2) and Tb (3) coordination polymers have been measured at room temperature.