Heterotrimetallic Organic Framework Assembled With Fe^Ⅲ/Ba^Ⅱ/Na^Ⅰ And Schiff Base:Structure And Visible Photocatalytic Degradation Of Chlorophenols

In this context, a porous heterotrimetallic organic framework composed of dicarboxyl-functionalized Schiff base ligands and metals, namely [BaNa（Fe-L）₂（μ₂-OH）（H₂O）]·DMF·2H₂O （1） [H₄L=1,2-cyclohexanediamino-N,N’-bis（3-methyl-5-carboxysalicylidene）], has been synthesized and characterized. Each FeⅢ ion is embedded in the internal [N2O2] pocket of L^4- anion, and further bridged by a μ₂-OH anion to give a （Fe-L）₂（μ₂-OH） dimer. Three unique BaⅡ ions exhibit two forms of coordination geometries. Each Ba1 and Ba2 ion is eight-coordinated by oxygen atoms from eight distinct L^4- anions, respectively. Ba3 is six-coordinated by four L^4- anions and two coordinated water molecules, exhibiting a distorted octahedral sphere. Both two NaⅠ ions are tetra-coordinated by oxygen atoms. Two forms of L^4- anions coordinate to （three Ba/two Na） and （two Ba/two Na） atoms, respectively. In this way, a porous 3D framework is engendered.A porous heterotrimetallic organic framework has been also characterized by UV-vis spectra （UV-vis）, infrared spectra （IR）, therogravimetric （TG） elemental analyses powder X-ray diffractions. Besides, we also have studied the gas sorption of 1. It is worth noting that the photodegradation property of 1 to 2-chlorophenol （2-CP）,3-CP and 4-CP at different pH values under visible light has been systematically investigated.