Two Cd(II) Coordination Polymers Based on a Flexible Tricarboxylate Ligand: Syntheses, Structures, and Photoluminescence and Catalytic Properties

Studies on the synthesis and design of coordination polymers (CPs) with flexible ligands are of great interest owing to their dynamic structures and promising applications. The title coordination polymers, {[Cd center dot(HTTTA)center dot(phen)]center dot 2H(2)O}(n) (1) and [Cd center dot(HTTTA)center dot(phen)](n) (2) (H(3)TTTA = 2,2',2 "-[1,3,5-triazine-2,4,6-triyltris (thio)] tris-acetic acid, phen = 1,10-phenanthroline) have been synthesized and characterized by elemental analysis, IR, powder XRD and single-crystal X-ray diffraction. Complex 1 consists of one CdII ion, one HTTTA(2-) ligand and one phen co-ligand. The Cd(II) metal clusters were bridged by the tridentate HTTTA(2-) ligands into infinite 1D chains, which are further connected into the 3D architecture by abundant hydrogen bonds. In 2, three carboxyl groups of HTTTA(2-) ligand show different coordination directions because of the C-S-C flexible bond angle, which leads to different 1D chains of 2. The strong pi-pi stacking interaction and four C-H center dot center dot center dot O hydrogen bonds connect the 1D chains into a 3D framework. The solid-state photoluminescence and catalytic properties were studied as well.