Guest Molecule Release Triggers Changes in the Catalytic and Magnetic Properties of a Fe^II-Based 3D Metal–Organic Framework

A Fe^II-based metal–organic framework (MOF), {[Fe₂(pbt)₂(H₂O)₂]·2H₂O}_<i>n</i>, undergoes an irreversible dehydration, which triggers changes in the catalytic and magnetic properties of the MOF. These property changes are attributed to the high-spin to low-spin transition of 7.1% center Fe^II, which is demonstrated by ⁵⁷Fe Mössbauer, X-ray photoelectron spectroscopy, and UV/vis absorption spectra

A Systematic Research on the Synthesis, Structures, and Application in Photocatalysis of Cluster-Based Coordination Complexes

To search for effective photocatalysts in the field of cluster-based coordination complexes, we synthesized {[Cd₂­(dcpp)­(beb)₂ (H₂O)]·H₂O}_<i>n</i> (<b>1</b>), [Cd₂­(dcpp)­(bmb)­(H₂O)₂]_<i>n</i> (<b>2</b>), {[Cd₂­(dcpp)­(2,2′-bipy)­(H₂O)₂]·2H₂O}_<i>n</i> (<b>3</b>), and {[Cd₂­(dcpp)­(4,4′-bipy)_0.5­(H₂O)₃]·H₂O}_<i>n</i> (<b>4</b>) by utilizing a butterfly-shaped multidentate carboxylic acid (4,5-di­(4′-carboxyl­phenyl)­phthalic acid) (H₄dcpp)) and N-donor ligands (1,4-bis­(2-ethyl­benz­imidazol-1-ylmethyl) benzene (beb), 1,4-bis­(2-methyl­benz­imidazol-1-ylmethyl) benzene (bmb), 2,2′-bipyridine (2,2′-bipy), 4,4′-bipyridine (4,4′-bipy)). Complexes <b>1</b>–<b>4</b> are constructed based on different SBUs. Complexes <b>1</b> and <b>2</b> possess three-dimensional (3D) pillar-layered frameworks based on noncluster-type SBUs and dinuclear Cd₂ clusters units, respectively. Complex <b>3</b> is a 3D porous structure building on Cd₄ clusters SBUs. Complex <b>4</b> is constructed from rare infinite botryoid-like Cd cluster chains and exhibits a 3D complicated framework. The research on optical energy gaps of complexes <b>1</b>–<b>4</b> indicates that these complexes are potential semiconductive materials. Moreover, complexes <b>1</b>–<b>4</b> are applied to catalyze the reaction of photocatalytic degradation of methylene orange (MO) under high-pressure mercury lamp irradiation. Excitingly, they exhibit good photocatalytic properties in the presence of H₂O₂, and the degradation rates for <b>1</b>–<b>4</b> increase from 43% (without photocatalyst) to 97, 78, 85, and 67%, respectively, after 100 min of irradiation. The photoluminescent properties of complexes <b>1</b>–<b>4</b> were also studied