Metal ion induced single-crystal-to-single-crystal transformation and luminescent sensing properties of resorcin[4]arene-based metal–organic frameworks

Abstract

In this work, two new resorcin[4]arene-based metal–organic frameworks (MOFs), namely, [(CH3)2NH2][Zn3(HL)(L)(DMF)(H2O)2]·2H2O (1-Zn) and [(CH3)2NH2]2[Cd3(L)2(H2O)4]·2DMF·2H2O (2-Cd), have been synthesized under solvothermal conditions (H4L represents the resorcin[4]arene-based ligand). 1-Zn exhibits a layer structure, while 2-Cd shows a 3D motif. Remarkably, by immersing 1-Zn in an aqueous solution of Cu2+ ions, a new Cu(II)-MOF [Cu2(H2L)2(H2O)2]·3.5H2O (1-Cu) was achieved via a metal ion induced single-crystal-to-single-crystal (SCSC) transformation manner, involving generation of new metal-O bond and change of metal ion coordination geometry. Moreover, luminescent detection properties for Fe3+ ions and Cr2O72− ions were also investigated with 1-Zn and 2-Cd as luminescent sensors.