Self‐Assembly of 1D, 2D, and 3D Lanthanide‐Metal Coordination Polymers Based on a 2‐(Pyridin‐4‐yl)‐4,5‐imidazoledicarboxylate Linker: Synthesis, Structures, and Luminescence

Three series of novel lanthanide‐based 1D, 2D, and 3D metallic coordination frameworks involving the 2‐pyridin‐4‐yl‐4,5‐imidazoledicarboxylic acid (H 3 PIDC) ligand have been characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, and single‐crystal X‐ray diffraction. The compound [Tb(PIDC)(H 2 O) 4 ] · H 3 PIDC · 4H 2 O ( 1 ) upon slow evaporation at room temperature gave a 1D coordination chain framework constructed of [Tb 2 O 2 ] dimers bridged through the carboxylate groups of PIDC 3– ligands; a 3D supramolecular structure is generated through hydrogen bonding and π–π interactions. The second kind of lanthanide‐based coordination framework, namely [Ln(H 2 PIDC)(ox)H 2 O] · 3H 2 O [Ln = Sm ( 2 ), Gd ( 3 ), Dy ( 4 ), and Ho ( 5 ), ox = oxalic acid], synthesized under hydrothermal conditions, self‐assemble through Ln 2 [H 2 PIDC] 2 building blocks and bridging oxalate ligands to give a 2D coordination layer structure. The adjacent layers stack to form a 3D supramolecular framework through weak interactions such as hydrogen bonding and π–π interactions. The third series of lanthanide‐based coordination compounds with chemical formula [Ln(HPIDC)(ox) 1/2 H 2 O] · 3H 2 O [Ln = Gd ( 6 ), Dy ( 7 ), Tb ( 8 ) and Ho ( 9 )] were also synthesized by hydrothermal reaction. These isostructural compounds contain an infinite –Ln–O–C–O–Ln– zigzag chain, which connect to each other through the oxygen atoms of the HPIDC 2– ligands to form a wave‐like layer. The layers are bridged by oxalate ligands to generate a 3D coordination framework.