Self-assembly, thermal stability and photoluminescence of two mixed-ligand silver(i) networks via 2D → 2D and 2D → 3D parallel interpenetration of (4,4) nets

Abstract

Two mixed-ligand silver(I) coordination polymers (CPs) [Ag₂(dmapym)₂(suc)·H₂O]_n (1) and [Ag₂(dmapym)₂(bdc)·2H₂O]_n (2), (dmapym = 2-amino-4,6-dimethylpyrimidine, H₂suc = succinic acid, H₂bdc = 1,3-benzenedicarboxylic acid), were synthesized and characterized. The structure of 1 presents an argentophilic interaction enhanced 2-crossing [2]-catenane motif formed between pairs of parallel interpenetrating 2D 4⁴-sql nets. For 2, as the dicarboxylate changes from flexible H₂suc to rigid V-shaped H₂bdc, each highly undulated 2D 4⁴-sql net was penetrated in parallel by the two nearest neighbouring ones and thus the overall 2D → 3D network is formed. The geometries and flexibility of dicarboxylates influence the coordination environments of metal ions and arrangement of ligands and thus determine the structures of the CPs. The photoluminescent and thermal properties of 1 and 2 have also been investigated.