Study On Luminescence And Catalysis Of Anion-Induced 3d-4f Poly-Nuclear Complexes

Carbon dioxide is widely considered as the major component of greenhouse.In another respect,CO₂ is the biggest environmentally abundant C1 building block and it is promising in transform into various chemicals.Numerous catalysts for the efficient synthesis of cyclic carbonates by using epoxides and CO₂ as the orginal ingredients have been developed.However,there were only three examples of 3d-4f catalysts to the coupling of CO₂ and epoxides to obtain cyclic carbonates.In this paper,we studied different series of anion-induced Zn-Ln polynuclear complexes,investigated their luminescence properties and the catalytic applications for the coupling of CO₂ and epoxides to obtain cyclic carbonates.The main contents include the following three parts:1.We introduce the anion-induced complexes in the difference of the structure,luminescence and magnetic properties.We briefly expound the luminescence of lanthanide complexes and 3d-4f complexes.And then we summarize the recent progress of Zn-complexes,rare earth complexes and 3d-4f complexes acted as catalysts for the synthesis of cyclic carbonatas from carbon dioxide and epoxide.2.A cost-effective o-vanillin derivative named methyl-3-methoxysalicylate?HL¹?as the ligand was used to coordinated to transition and rare earth salts with different anions to construct two series of 3d-4f clusters:Ln₂Zn₂ where Ln^?=Eu³⁺,Tb³⁺,Er³⁺,Yb³⁺,Nd³⁺and Ln₂Zn₄(Ln^?=Tb³⁺,Nd³⁺).The luminescence spectra show excellent luminescence properties with relatively high luminescence quantum yields and long luminescence lifetimes in visible and near infrared regions,respectively.The replacement of the nitrate anion with the acetate anion not only lead to structural changes dramatically but also luminescent properties of the 3d-4f clusters enormously.In addition,we also found these clusters exhibit excellent catalytic activity on the cycloaddition between CO₂ and epoxides to obtain cyclic carbonates under mild conditions?80 ^oC,1 atm?and even under ambient condition.They are regarded as the highly selectivity and broad-substrate catalysts.3.We synthesized a pyridyl acylhydrazones ligand H₃L² based on 2-hydroxynicotinic acid,and synthesized three series of complexes with different structures through solvothermal method.Luminescence spectra show that the acylhydrazide ligand can sensitize the near-infrared luminescence of rare earth ions(Er³⁺,Yb³⁺),and its near-infrared luminescence decreases with the increase of Zn²⁺in the complexes structures.In addition,we studied the properties of these complexes in the catalytic synthesis of cyclic carbonates.In contrast to widely accepted bimetallic synergy effect,we found that the more Zn²⁺,the lower catalytic activity of complexes.The mechanism of this unusual phenomenon is further studied in our laboratory.Based on this acylhydrazide ligand,we also obtained a Zn-complex,the crystal structure indicates that it is a one-dimensional infinitely extended structure.Catalytic studies show that the Zn-complex can be used as a good catalyst on the cycloaddtion reaction of CO₂ and epoxides to obtain cyclic carbonates.