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

Abstract

Four new rare earth organometallic coordination polymers [EuIII(Hbidc)(pdc)·2(H2O)]2·4H2O (1), [TbIII(Hbidc)(pdc)·2(H2O)]2 (2), and {[LnIIIAgI(bidc)(pdc)·2(H2O)]}n·H2O (Ln=Eu (3), Tb (4)) (H2bidc=1H-benzimidazole-5,6-dicarboxylic acid, H2pdc=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.