The Research Of Confined Space Self-assembly And Its Catalytic Performance

In the research of supramolecular chemistry,the supramolecular metal assembly system has such problems as weak stability and easy aggregation.Therefore,the higher stability can be granted to the metal assembly system,which can greatly expand the application field of the metal assembly system.Based on the research of metal assemblies and mesoporous materials,we constructed organic-inorganic hybrid materials using the self-assembly strategy of confined space,and explored and studied the functions and potential applications of these supramolecular composite materials.This thesis is divided into the following sections:In chapter one,the research status of self-assembly and its application were briefly introduced.Then our projects in this paper were put forward at the end of this chapter.In the second chapter,inspired by the self-assembly behavior in nature,using the efficiency of coordination-driven self-assembly strategy and the cavity limiting property of porous materials,we designed and synthesized a two-dimensional supramolecular metallocycles containing iridium from pyridine ligand containing metal iridium(Ir)via platinum coordination-driven self-assembly.Then the organic-inorganic hybrid material was constructed by the principle of size matching,which was compounded with SBA-16 porous silicon material.And a series of structural characterization is carried out.Because of high dispersity of metallacycles within the mesoporous cavitiels,the stability and activity of Ir-containing metallacycles were obviousy improved.For ex-ample,the catalytic efficiency of the complex in catalyzing the reaction from amine to imine is 4 times that of the metallacycles alone.Thus the resultant hybrid material has been successfully employed as a heterogeneous catalyst for photooxidation of amines.In the third chapter,from the previous chapter,we have successfully realized the recombination of two-dimensional metallacycles and mesoporous silicon.On this basis,we designed and synthesized TEMPO-modified assembly motifs and synthesized three-dimensional supramolecular metal-organic cage through coordination-drived self-assembly.After modification,amino-modified mesoporous carbon material FDU-ED was synthesized.Then a class of organic-inorganic hybrid supramolecular metal assemblies with dual catalytic sites were prepared by using coordination-driven self-assembly strategy.To demonstrate the utility of our bifunctional Complex catalyst,a one-pot alcohol oxidation/Knoevenagel condensation which can be viewed as two separate steps: a TEMPO-promoted alcohol oxidation followed by an amine-promoted Knoevenagel reaction,was studied.The experimental results prove that it has a good catalytic effect on aromatic alcohols and fatty alcohols with different substituents,verifying the general utility of Cage@FDU-ED for the successive selective oxidation-Knoevenagel reaction.Note that one-pot reaction can avoid tedious isolation and purification of the reaction intermediates,thus allowing for a simpler and greener process.Because of the easy preparation,fine-tuned sizes,shapes and functionalities of both metallosupramolecular complexes and mesoporous matrix,the confinement selfassembly strategy demonstrated herein have the potential to allow chemists to easily predict and therefore design one-pot multistep syntheses based on new heterogeneous catalysts.Studies aimed at designing new metallosupramolecular complexes based catalysts for advanced sequential catalysis applications are currently underway in our laboratory.