Syntheses,Structures And Catalytic Properties Of Complexes Based On Imidazole-containing Thiacalix[4]arene

In this paper,a new imidazole-based thiacalix[4]arene ligand L was designed and synthesized.Threecoordinationcompounds,namely,[Cu₄(SiW₁₂O₄₀)（L）₂（DMF）₂]·2EtOH·DMF（1）,[Ag₄(PMo₁₂O₄₀)（L）₂]·OH（2）and[Co₂（L）（Cl）₄]·8H₂O（3）,were obtained by using the L under solvothermal conditions.Crystal structures of 1-3 was determined by X-ray diffraction analyses and characterized by IR,PXRD,TGA and elemental analysis.In 1 and 2,two ligands were linked by one[SiW₁₂O₄₀]^4-or[PMo₁₂O₄₀]^3-anion via two metal cations to give molecular dimers.Dimer molecules in 1are linked by hydrogen bonds to give a 2D supramolecular structure.Dimer molecules in 2are linked by Ag···O weak interactions and hydrogen bonds to form a 2D supramolecular structure.3 is a 3D metal-organic framework structure.Both 1-3 have well thermal stability.In addition,the chemical stability and catalytic properties of 1-2 were also investigated.1-2 are stable in aqueous solutions with different pH values and organic solvents.Considering the catalytic activity of Cu（I）site in 1,we investigated its usage as a catalyst for the azide-alkyne cycloaddition（AAC）.The experimental results show that 1 has good catalytic performance for AAC reaction.2 contains[PMo₁₂O₄₀]^3-,which can catalyze the desulfurization reaction.The experimental results show that 2 has excellent catalytic effect on oxidative desulfurization reaction and still has high catalytic activity after four cycles.