Mono- and heterometallic europium (III) and terbium (III) complexes: Synthesis, crystal structures and luminescent properties

Abstract Four new rare earth organometallic coordination polymers [Eu III (Hbidc)(pdc)·2(H 2 O)] 2 ·4H 2 O ( 1 ), [Tb III (Hbidc)(pdc)·2(H 2 O)] 2 ( 2 ), and {[Ln III Ag I (bidc)(pdc)·2(H 2 O)]} n ·H 2 O (Ln = Eu ( 3 ), Tb ( 4 )) (H 2 bidc = 1H-benzimidazole-5,6-dicarboxylic acid, H 2 pdc = 2,6-pyridine dicarboxylic acid) have been synthesized through self-assembly reactions. The X-ray single crystal diffraction indicates that these complexes are isomorphous, namely triclinic P − 1. Interlayer O–H⋯O and C–H⋯O hydrogen bonding has been observed in the structure of four complexes, generating 1D zigzag infinite chain, 2D plane layer, and even 3D ladder-like supramolecular framework. Addition of silver nitrate to chemicals leads to massive restructuring and emission intensity enhancement of complexes 3 and 4 . Furthermore, thermal stabilities and luminescent of 1 – 4 have also been discussed in detail.