Syntheses,Structures And Catalytic Properties Of The Coordination Polymers Based On Pyridyl-functionalized Thiacalix[4]arene

Thiocalixarene has a large cavity,a flexible structure,a rich conformational behavior,and the possibility of various chemical modifications,which has attracted extensive attention in the field of supramolecular chemistry,coordination chemistry and materials.In this paper,we prepared two pyridyl-functionalized thiacalix[4]arene ligands L1 and L2?L1=25,26,27,28-Tetra[?2-pyridylmethyl?oxy]-2,8,14,20-tetrathia-calix[4]arene,L2=25,26,27,28-Tetra[?2-pyridylmethyl?oxy]-5,11,17,23-tetra-tert-butyl-2,8,14,20-tetrathia-calix[4]arene?.Five coordination polymers,namely,[Cu₄Cl₄?L1?]·CH₃OH·1.5H₂O?1?,[Cu4Br4?L1?]·DMF·0.5H2O?2?,[Co2?OH?4?H2O?2?L1?]?3?,[Cu4Cl4?L2?]2CH3OH?4?and[Cu4Br4?L2?]?5?were assembled with L1/L2 and metal salts under solvothermal conditions.Among them,1 and 2 are isomorphic,exhibiting charming three-dimensional?3D?framework with a channel dimension of ca.6.6×10?².3 displays a mononuclear unit,and the units are linked by C–H···O interactions to form a chain.Isomorphic 4 and 5 show single-chain structures,giving single-chain structures.Remarkably,1 and 2 exhibit great stability in aqueous solutions of wide pH range and various organic solvents.Considering that 1 and 2 both contain Cu?I?sites,their catalytic performances as heterogeneous catalysts for azide-alkyne cycloaddition reactions?AAC?and epoxide ring-opening reactions have been studied.The results show that 1,as recycled heterogeneous catalysts,features high efficient catalytic capacities for the AAC reaction and epoxy ring opening reaction.The exposed active Cu?I?sites and the 1D channel of 1 play key roles in the improvment of the catalytic activities.This work has accumulated experimental foundations for the design and self-assembly of environmental friendly metal-organic frameworks with high catalytic activity and reusability.