Two Heterometallic-organic Frameworks Composed Of Iron(iii)-salen-based Ligands And D10 Metals: Gas Sorption And Visible Photocatalytic Degradation Of 2-chlorophenol

In this work, two examples of heterometallic-organic frameworks(HMOFs) composed of dicarboxyl-functionalized Fe(III)-salen complexes and d10(Zn, Cd) metals,[Zn2(Fe-L)2(μ2-O)(H2O)2]·4DMF·4H2O(1) and [Cd2(Fe-L)2(μ2-O)(H2O)2]·2DMF·H2O(2)(H4L = 1,2-cyclohexanediamino-N,N’-bis(3-methyl-5-carboxysalicylidene), have been synthesized and structurally characterized. In HMOF 1, two Zn(II) atoms show different coordination geometries: Zn1 is in a slightly distorted tetrahedral coordination sphere, Zn2 is in an octahedral coordination sphere, respectively. In HMOF 2, the three independent Cd(II)atoms are six coordinated in distorted octahedral coordination geometries, and Cd1-Cd3 are held together with the help of eight carboxylate groups to yield a tetranuclear[Cd4(COO)8(H2O)2] cluster. In 1 and 2, each square pyramidal Fe(III) atom is embedded in the [N2O2] pocket of L4- anion, which are further bridged by a μ2-O anion to give a(Fe-L)2(μ2-O) dimer. Two carboxylate groups of each L4- anion bridges Zn(II) or Cd(II) atoms to afford a 3D porous HMOF.The two porous heterometallic-organic frameworks have been also characterized by elemental analyses, infrared spectra(IR), powder X-ray diffractions and therogravimetric(TG)analyses. In addition, the gas sorption and magnetic properties of 1 and 2 have been studied.Remarkably, 1 and 2 show actively photocatalytic degradation of the 2-chlorophenol(2-CP)under visible-light irradiation. It also represents the first report that Fe(III)-salen-based HMOFs exhibit photodegradation of 2-CP.