Two Heterometallic–Organic Frameworks Composed of Iron(III)‐Salen‐Based Ligands and d¹⁰ Metals: Gas Sorption and Visible‐Light Photocatalytic Degradation of 2‐Chlorophenol

Abstract

Two examples of heterometallic-organic frameworks (HMOFs) composed of dicarboxyl-functionalized Fe(III)-salen complexes and d(10) metals (Zn, Cd), [Zn2(Fe-L)2(μ2-O)(H2O)2]⋅4 DMF⋅4 H2O (1) and [Cd2(Fe-L)2(μ2-O)(H2O)2]⋅2 DMF⋅H2O (2) (H4L = 1,2-cyclohexanediamino-N,N'-bis(3-methyl-5-carboxysalicylidene), have been synthesized and structurally characterized. In 1 and 2, each square-pyramidal Fe(III) atom is embedded in the [N2O2] pocket of an L(4-) anion, and these units are further bridged by a μ2-O anion to give an (Fe-L)2(μ2-O) dimer. The two carboxylate groups of each L(4-) anion bridge Zn(II) or Cd(II) atoms to afford a 3D porous HMOF. The gas sorption and magnetic properties of 1 and 2 have been studied. Remarkably, 1 and 2 show activity for the photocatalytic degradation of 2-chlorophenol (2-CP) under visible-light irradiation, which, to the best of our knowledge, is the first time that this has been observed for Fe(III)-salen-based HMOFs.

Recent advances in MOF-based photocatalysis: environmental remediation under visible light

“…93 As for MOFs with mixed metals, 90 partial substitution of metal centers could regulate their efficiency for charge separation as well as photocatalytic performance. 92, [94][95][96][97][98][99][100][101][102][103][104][105][106] Oxobridged heterometallic assemblies with more flexibility and tenability can be formed within the same MOFs. 92, 99 For example, Ni-doped ZIF-8 was fabricated via a one-pot mechanochemical method.…”

TiO2 Nanoparticles Anchored onto the Metal–Organic Framework NH2-MIL-88B(Fe) as an Adsorptive Photocatalyst with Enhanced Fenton-like Degradation of Organic Pollutants under Visible Light Irradiation

“…Metal–organic frameworks (MOFs) are promising in the fields of gaseous capture/separation, optical materials, sensing, and catalysis . In recent years, they have been widely employed as new types of photocatalysts due to their ligand–metal charge transfer (LMCT) properties when subjected to irradiation with light. − Among reported MOFs, Fe-based MOFs have been demonstrated to generate •OH radicals effectively via a heterogeneous photo-Fenton-like process , and could be employed to degrade the organic pollutants in effluent. − However, these iron-based MOFs have low adsorption properties toward dye molecules , and photogenerated electron–hole (e – -h + ) pairs easily recombine, , inhibiting their photocatalytic activities.…”

Towards the use of metal–organic frameworks for water reuse: a review of the recent advances in the field of organic pollutants removal and degradation and the next steps in the field

“…Due to their toxicity and high solubility in water, they are ranked as severe environmental pollutants. 123 2-Chlorophenol was successfully photodegraded under visible light with two MOFs: 124 ). ZnMOF performed better than CdMOF, but no explanation was provided for this trend.…”