Solvent-Induced Carboxylate Shift and Movement of an Anthryl Side-Group in Single-Crystal to Single-Crystal Structural Dynamics in a Gadolinium Coordination Polymer

Abstract

Single crystal to single crystal (SC–SC) transformation involving cooperative movement of atoms represents one of the most fascinating phenomena in coordination polymers. Here, we describe a novel two-dimensional coordination polymer {[Gd2(L)3(DMF)2(H2O)2]·(DMF)2·(H2O)5.5}n (1) synthesized from carboxylate-based flexible ligand 5-[(anthracen-9-ylmethyl)-amino]-isophthalic acid and Gd(III) ion by the solvothermal technique. The complex undergoes solvent-induced rearrangement reactions with the cleavage and formation of coordination bonds and substantial movement of the anthracene side groups without losing crystallinity to form the daughter products as {[Gd2(L)3(H2O)4]·(DMF)4·(H2O)1.5}n (1a), {[Gd2(L)3(DMF)2(H2O)]·(DMF)2·(DCM)2·(H2O)5}n (1b), and [Gd(L)2(DEF)]n (1c). These transformations exhibit a crystallographic snapshot of “carboxylate-shift” process which is further supported by IR spectroscopy, elemental analysis, and powder X-ray diffraction patterns. To the best of our knowledge, it is the first ex...