Metal-directed assembly of two 2-D 4d–4f coordination polymers based on elliptical triple-deck cylinders hinged by meso-double helical chains

Two 2-D 4d–4f coordination polymers based on elliptical triple-deck cylinders hinged by meso-helical chains containing an isonicotinate ligand, namely, {[Ag2Ln(IN)4(H2O)2]·(NO3)·(H2O)}n (Ln = Sm and Eu, IN− = isonicotinate), have been successfully constructed through the transformation of a single-crystal to single-crystal (SC-SC) or different metal–organic polymer units, in which the recognition between the organic ligand and two types of metal ions direct the formation of the final productions.