[Fe3(HCOO)6]: A Permanent Porous Diamond Framework Displaying H2/N2 Adsorption, Guest Inclusion, and Guest-Dependent Magnetism

Authors

  • Z.-M. Wang,

    1. Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (P.R. China)
    Search for more papers by this author
  • Y.-J. Zhang,

    1. Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (P.R. China)
    Search for more papers by this author
  • T. Liu,

    1. Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (P.R. China)
    Search for more papers by this author
  • M. Kurmoo,

    1. Laboratoire de Chimie de Coordination Organique, CNRS-UMR7140, Institut Le Bel, Université Louis Pasteur, 4 rue Blaise Pascal, 67000 Strasbourg Cedex 01 (France)
    Search for more papers by this author
  • S. Gao

    1. Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (P.R. China)
    Search for more papers by this author

  • This work was supported by the National Natural Science Foundation of China (No.  20571005, 20221101, 20490210, 90201014), the National Basic Research Program of China (2006CB601102), and CNRS, France. The authors thank Prof. Xingguo Li and Yan Li of the College of Chemistry and Molecular Engineering, Peking University for their kind help in H2 adsorption measurements. Supporting Information is available online from Wiley InterScience or from the author.

Abstract

The porous magnet [Fe3(HCOO)6], the iron member of the [M3(HCOO)6] family (where M = Mn, Fe, Co, Ni, etc.), based on a diamond framework consisting of Fe-centered FeFe4 tetrahedral nodes, is prepared successfully by using a solution-chemistry method. The as-prepared compound, [Fe3(HCOO)6](CH3OH)1.5(H2O)0.5 (1-parent), exhibits facile removal of its guests, methanol, and water, to give the desolvated framework [Fe3(HCOO)6] (2-empty) that displays permanent porosity and thermal stability up to 270 °C. The flexibility of the framework and the amphiphilic nature of the surface of the pores consisting of both C–H and O arrays allows 2-empty to take up significant H2 and N2 at liquid-nitrogen temperatures and a wide spectrum of both polar and nonpolar guests of different sizes. A series of guest-inclusion compounds, [Fe3(HCOO)6](I2)0.84 (3-iodine), [Fe3(HCOO)6](C4H8O) (4-THF), [Fe3(HCOO)6](C4H4O) (5-furan), [Fe3(HCOO)6](C6H6) (6-benzene), [Fe3(HCOO)6](CH3CN) (7-acetonitrile), and [Fe3(HCOO)6]((CH3)2CO) (8-acetone) are successfully prepared by vapor diffusion of the guest into the pores of 2-empty and their structures are characterized by using single-crystal X-ray crystallography. Zigzag molecular arrays of the guest are formed in the confined channels of the host framework, and the weak hydrogen-bonding provides the main host–guest interaction. All the compounds show 3D long-range magnetic ordering and guest-modulated Curie temperatures, coercive fields, and remnant magnetization as a consequence of the subtle rearrangement of the magnetic framework that conforms to the size of the guests and the difference in host–guest interactions. A possible magnetic structure of the framework is proposed to account for magnetic competition and geometrical frustration. The thermal and spectroscopic properties of the compounds are also reported.

Ancillary