Expanding the Variety of Zirconium-based Inorganic Building Units for Metal-organic Frameworks.

Author(s) Leubner, S.; Zhao, H.; Van Velthoven, N.; Henrion, M.; Reinsch, H.; De Vos, D.; Kolb, U.; Stock, N.
Journal Angew Chem Int Ed Engl
Date Published 2019 May 14
Abstract

Two new zirconium based metal-organic frameworks with the composition [Zr6O4(OH)4(OAc)6(BDC)3] (CAU-26) and [Zr5O4(OH)4(OAc)4(BDC)2] (CAU-27) are reported, which were synthesized from acetic acid, a rarely utilized but green and sustainable solvent (BDC2-: 1,4-benzenedicarboxylate). Structure determination aided by automated electron diffraction tomography revealed that CAU-26 is composed of layers of well-known {Zr6O8} clusters interconnected by terephthalate ions. In contrast CAU-27 exhibits a three dimensional structure with a so far unknown type of one-dimensional inorganic building unit (IBU), which can be rationalized as condensed polyhedron-sharing chains of {Zr6O8} clusters. CAU-26 occurs as an intermediate of the CAU-27 synthesis and can be isolated easily, when reaction temperature and time are decreased. We were also able to synthesize two isoreticular derivatives of CAU-27 with extended linker molecules by implementing 4,4'-biphenyldicarboxylic acid (H2BPDC) and 5,5'-dicarboxy-2,2'-bipyridine (H2BIPY). All materials show high thermal and chemical stability as well as permanent microporosity. The excellent stability of CAU-27-BIPY was exploited to synthesize a performant iridium-supported heterogeneous MOF-based catalyst for the direct C-H borylation of arenes.

DOI 10.1002/anie.201905456
ISSN 1521-3773
Citation Leubner S, Zhao H, Van Velthoven N, Henrion M, Reinsch H, De Vos D, et al. Expanding the Variety of Zirconium-based Inorganic Building Units for Metal-organic Frameworks. Angew Chem Int Ed Engl. 2019.