Design、Synthesis And Applications Of Three Dimensional Organic Porous Materials Base On Imine Bonds

Porous materials play vital roles in many fields of science and technology and have recently attracted much attention as a beneficial platform for advanced functional materials’design.The rational design and functionalization of Metal-organic frameworks（MOFs）and Covalent-organic frameworks（COFs）,as two new types of crystalline porous materials,have been one of the hot issues for chemists.As a subset of the general family of crystalline porous materials,MOFs possesses ordered and well-defined pore structures.MOFs are comprised of inorganic nodes（metal cations or metal clusters（secondary building units,SBUs））and N-donor or carboxyl ligands linked via coordinative bonds.In contrast,COFs are generally constructed by covalent bonds between light elements（such as carbon,boron,oxygen,nitrogen）to form regular networks.Owing to the fact that MOFs and COFs offer many intriguing properties as two types of representative porous materials,including high porosity,low density,ultrahigh specific surface area and tunable functionality,the past two decades have witnessed a notable growth in research and development of crystalline porous materials.As a result,MOFs and COFs have showed potential applications in many fields,such as gas storage and separation,heterogeneous catalysis,fluorescence,chemical sensing,drug delivery and release,electrochemistry and so on.And they have become an ideal candidate due to their excellent performance.Nevertheless,there are few researches that combine the chemistry of MOFs and COFs.Due to the diversities of SBUs and organic ligands,various functional MOFs can be obtained easily.However,it still remains a huge challenge in preparing MOFs with high porosity and BET surface area.Furthermore,an important challenge in COFs materials science is the design of functional COFs whose properties can be controlled through pre-designed strategies.Many researches about two dimensional functional COFs have made them promising for a range of practical applications to date.Nevertheless,the reports associated with three dimensional functional COFs which stimulate many research interests are still rare.Considering the questions mentioned above,two types of three dimensional crystalline porous materials were designed and synthesized successfully in this thesis.Subsequently,their structures and properties were characterized.The main contents are summarized as the following two aspects.（1）As a new tetratopic building blocks with tetrahedral configuration,tetrakis（3-formyl-4-hydroxylphenyl）methane（TFHPM）were prepared.And then TFHPM was reacted with 4,5-difluorophenylene-1,2-diamine（DFPDA）or4,5-dichlorophenylene-1,2-diamine（DCPDA）under solvothermal conditions to afford two kinds of three dimensional salphen-based COFs,namely JUC-508 and JUC-509respectively.Interestingly,both 3D Salphen-based COFs adopted non-interpenetrated dia topology structure which is rare in 3D COFs.Furthermore,3D Salphen-based COFs possessed microporous structures,large specific surface area and good chemical stability.Benefiting from the Salphen units in the skeleton of JUC-509,it was modified with three different kinds of metal cations,denoted as JUC-509-Y（Y=Mn/Cu/Eu）.Most of the Salphen pockets were occupied by metal cations.Finally,their performance in eliminating superoxide radicals was studied and the Cu（II）-Salphen COF displays highest activity among them that can be attributed to high catalytic effect of Cu（II）ions.The scavenging order of Salphen-COFs on superoxide radicals was listed as follows:JUC-509-Cu>JUC-509-Mn>JUC-509-Eu.Besides JUC-509 and JUC-509-Eu had no obvious antioxidant activity.The recycle experiments demonstrated that JUC-509-Y can be reused at least three times without obvious loss of activity.（2）Three crystalline porous materials with three dimensional networks,termed coordination covalent organic frameworks（CCFs）,were prepared using a strategy that combines the chemistry of MOFs and COFs.The solvothermal reactions of1,3,5-triformylphloroglucinol（TFP）,Zn（II）cations and amine-containing carboxyl linkers afforded 3D-CCF-1,3D-CCF-2 and 3D-CCF-3 in one pot.The topology of all3D CCFs with Zn₄O-based secondary building units（SBUs）is described as qom net that are isostructural with MOF-177.In addition,alkaline NH groups arising from a enol keto tautomerism in the skeleton were obtained simultaneously.Their porosities and BET surface areas were characterized by N₂ adsorption measurements.Encouraged by their high surface areas and structural characteristics（Lewis acid sites and basic sites）,all 3D CCFs may catalyze tandem reactions as potentional acid-base bifunctional catalysts.