Impact Of Introducing Polar Functional Groups On The Properties Of Schiff-base Macrocyclic Complexes And Porous Materials

Structure-function relationships have attracted enormous attention due to the opportunity to finely tune the properties of some molecules and materials.The incorporation of polar functional groups into certain structures is believed to be an efficacious strategy to acquire improved properties than the original compounds.This paper deals mainly with the incorporation of three polar functional groups(sulfone,P=O and ketone)involving the area of Schiff-base macrocycles,metal-organic frameworks and organic molecular cages.The abstract of the work is synthesis of sulfone-functionalized Schiff-base macrocyclic complex with enhanced enhanced antimicrobial activities through post-modification,cavity partition and functionalization of a[2+3]organic molecular cage by inserting polar P=O bonds and polar ketone-functionalized metal-organic framework showing a high CO2 adsorption performance,respectively.And the details are divided into the following parts:Chapter 1:Introduction.Here we focus on the background of Schiff-base macrocycles,metal-organic frameworks and organic molecular cages.In this part,we firstly introduce the Schiff-base macrocyclic complexes from the perspective of macrocyclic chemistry and supramolecular chemistry.The choice of appropriate dialdehyde and diamine precursors is worthy of attention.Control synthesizing strategy is another critical factor,including non-templated and templated methods.The above mentioned details are helpful in the synthesis of various Schiff-base macrocycles.Metal organic framework is a focal porous material,and we summarize its current research on CO2 gas adsorption and general strategies to enhance CO2 adsorption performance,such as creating open metal sites and introducing polar functional groups.Porous organic molecular cage as a new kind of material is reviewed from the viewpoint of development and synthetic strategy.It is demonstrated that using the substrates containing three identical functional groups with 1200 and dynamic reversible chemistry is beneficial to construct the organic molecular cages.Chapter 2:Construction of sulfone-functionalized[2+2]Schiff-Base macrocyclic dinuclear Zn(?)complexes and the study of corresponding antimicrobial activities.We aim to introduce heteroatom into the Schiff-base macrocycle,and synthesized a novel dialdehyde with two embedded sulfur atoms.A[2+2]sulfur-bridged Schiff-base dinuclear macrocyclic Zn(?)complex was produced by the template-assisted synthesis.The sulfur atoms in sulfur-bridged Schiff-base macrocycle can be selectively oxidized to sulfone groups,because the easily oxidized aldehyde groups have been transformed into the imine connected macrocycle and stabilized by the following Zn(?)ion complexation.In addition,another oxygen-unstable phenolic hydroxyl groups have been deactivated via electron delocalization originated from the formation of coordinative bonds with Zn(?)ions.More interestingly,the sulfone-functionalized Schiff-base macrocyclic complex with dual bioactive sites displays enhanced antimicrobial activities in contrast to the undecorated macrocycle.Chapter 3:Cavity partition and functionalization of a[2+3]Schiff-base organic molecular cage by inserting polar P=O bonds.Pore-size control through pore space partition strategy has been performed to elevate the seiectivities of gas separations.We synthesized a[2+3]organic molecular cage with inner-directed P=O bonds.The cavity of the organic molecular cage was partitioned and functionalized by inserting polar P=O bonds.Structural analysis reveals that the cavity has been partitioned into three small subunits,which is comparable with that of CO2 but not with CH4.Gas adsorption experiments show selective CO2 capture and CH4 exclusion.First-principle calculations give theoretical support on the importance of the P=O bond partition and functionalization to selective CO2 adsorption.Chapter 3:Construction of[4+4]phosphate organic molecular cage.The phosphate based trialdehyde as a flexible substrate can be assembled into a[4+4]phosphate cage.The orientation of P=O bonds is not directed towards the center of the cage due to different configurations of three benzene rings.The adsorption measurements reveal that the[4+4]cage has selective CO2 adsorption over CH.Chapter 4:Polar Ketone-Functionalized Metal-Organic Framework and the studies of its gas adsorption performance.The incorporation of various polar functional groups into porous metal-organic frameworks(MOFs)represents an efficacious strategy to improving their gas adsorption properties.In this part,a polar ketone-functionalized MOF was synthesized.Structural analysis reveals that the new MOF possesses channels decorated by the carbonyl groups and rhombicuboctahedral cages,with open Cu(II)sites pointing toward the cage center.The framework exhibits exceptionally high H2(2.8 wt%at 77 K and 1 bar)and CO2(46.7 wt%at 273 K and 1 bar,21.8 wt%at 298 K and 1 bar)uptake.Furthermore,it displays high selectivities of CO2 adsorption over N2(4.9-5.4)and CH4(14.7-19.7)at 298 K.In summary,polar functional groups(sulfone,P=O and ketone)as functionalized sites have been incorporated into Schiff-base macrocycle,MOF and organic molecular cage,respectively.The introducing of these functionalities has been demonstrated to improve the corresponding properties.It is believed that the well-establishment of structure-function relationships can throw some light on the design of novel functionalized molecules and materials.