Postsynthetic polymer-ligand exchange hybridization in M-MOF-74 composites.

A series of new polymer-inorganic composites has been synthesized from poly(amic acid) (PAA) and various M-MOF-74 (M = Mg, Mn, Co, Ni, Zn) frameworks using a postsynthetic ligand exchange strategy, wherein ligand moieties built into the PAA backbone are exchanged with MOF-bound ligands. The reaction is monitored by UV-vis spectroscopy in order to compare exchange rates for different metal ions, and the resulting composites are characterized by powder X-ray diffraction and scanning electron microscopy. This method of polymer-ligand exchange (PLE) hybridization has only been previously demonstrated using Zn2+-carboxylate and Zn2+-imidazolate frameworks; therefore, this work further reveals the versatility of PLE by showing that exchange is possible for several additional metal ions, as well as frameworks containing 2,5-dihydroxyterephthalate ligands. [ABSTRACT FROM AUTHOR]