Syntheses And Properties Of Ionic Two-component Hydrogen-bonded Organic Frameworks

Hydrogen-bonded organic frameworks(HOFs)are crystalline porous materials formed by the self-assembly of small organic molecules or metal-organic compounds through intermolecular hydrogen bonds.Compared with metal-organic frameworks(MOFs)and covalent organic frameworks(COFs),HOFs have the advantages of strong solution processability,recyclability,and easy film formation.At present,it has been widely used in gas adsorption and separation,fluorescence detection,catalysis,proton conduction,etc.It is relatively difficult for one-component HOFs to introduce functional sites into the framework.At present,there are only a few reports on the catalytic application of HOFs to introduce sites through coordination bonds.It is worth noting that the strength of coordination bond is stronger than hydrogen bond.This method has a small scope of application.Two-component HOFs of acid-base ionic type have attracted our attention.First,acid-base ionic two-component HOFs have stronger bonds than single-component HOFs,and they are not easy to form hydrogen bonds with solvents.Second,with the composition of one acid and one base,the monomers preferentially form bonds,which facilitates the introduction of functional sites.At the same time,it is precisely because of the diversification of the ingredients that the control methods are more diversified.Therefore,we adopt the system of N,N'-bis(5-isophthalic acid)naphthalenetetraimide(H₄L)and DMF,one acid and one base.In chapter one,FJU-200 was synthesized by solvent hydrothermal method.By immersing in the aniline solution,the transformation from single-crystal to single-crystal was achieved,and the crystal changed from light yellow to deep red Ph NH₂@FJU-200.In addition,FJU-200 got dark brown crystal UV-FJU-200 under the irradiation of 365 nm UV lamp.FJU-200,Ph NH₂@FJU-200,and UV-FJU-200 are all crystallized in the P-1space group of the triclinic system,and they are all two-dimensional hydrogen-bonded organic frameworks.FJU-200 is a dual-functional hydrogen-bonded organic framework that can detect aniline and ultraviolet light.The detection of aniline is based on the hydrogen bonding between host and guest,and the carbonyl site of H₄L plays an important role.The detection of ultraviolet light is based on the change of the hydrogen bond.In chapter Two,two HOFs FJU-201 and FJU-202 were synthesized by solvent hydrothermal method,with the guest molecule p-xylene and toluene,respectively.Single crystal X-rays show that FJU-201 and FJU-202 belong to the P-1 space group of the triclinic system and have one-dimensional diamond-shaped holes,and are two-dimensional hydrogen bond organic framework.FJU-201 has one-dimensional diamond-shaped pores with a pore size of 10.78×8.60(?)~2.And this aperture size is can package p-xylene.More importantly,p-xylene can form multiple hydrogen bonds with the framework,in which the carbonyl group of H₄L plays an important role.This multiple hydrogen bonding results that in mixed xylene or xylene and toluene,FJU-201 can form selectivity but not FJU-202.