A Topologically New Cd(II) Coordination Polymer with the Reversible Dehydrated-Rehydrated Ability and Concomitant Luminescent Transfer

Abstract

The Cd(II)–L carboxylate motifs mediated by the bpp ligand afforded a topologically new coordination polymer by hydrothermal reaction, namely, [Cd₂(L)(bpp)₂(H₂O)₂]·2H₂O ([1·(H₂O)₂]·2H₂O) (H₄L = 5-(2,3-Dicarboxy phenoxy)isophthalic acid and bpp = 1,3-bis(4-pyridyl)propane). It is further characterized by elemental analysis, IR, thermogravimetric analysis (TGA) and fluorescence analysis. The single crystal X-ray diffraction revealed that the structure features the Cd(II)-carboxylate layer motifs cross-linked by the bpp coligands to construct a 3D metal-organic framework with a (4,4,4)-connected {4.5.6².7.8} {4.5².6².8}{5².6².7.8} new framework topology. The TGA shows that the compound exhitits good thermal properties with reversible dehydrated-rehydrated ability without destroying the framework integrity. In addition, the dehydration/rehydration process is accompanied with a unusual phenomenon of fluorescence transfer, which makes it great potential in minimum moisture detection.