Study On The Preparation Of Benzo-21-crown-7 Derivatives And Supramolecular Adhesion System

High-performance organic materials are extremely important to meet people's growing needs.As the first generation of macrocyclic molecules,crown ethers have opened an important research direction in the field of supramolecular chemistry since their appearance.Since their discovery,crown ether molecules have been used to synthesize a variety of good-performance materials such as supramolecular polymers,drug controll-and-release carriers,artificial muscles,molecular channels,etc.Among them,benzo-21-crown-7(B21C7)is used the most widely.In the past researches,the synthesis and preparation process of B21C7 and its derivatives were complicated,but the yield is low,which has been restricting the furthermore development of functional supramolecules which use B21C7 as their main bodies.At the same time,with the development of smart machines,people's demand for adhesives with good adhesion properties is increasing.In the currently prepared supramolecular adhesives,people have achieved viscosity by designing and modifying molecular monomers,and the process are complicated and the cost is high.Therefore,it is necessary to develop new methods to prepare supramolecular adhesives.Starting from the preparation of B21C7,this paper developed a simple and efficient method for synthesizing B21C7 and its derivatives.Based on this,two crown ether supramolecular adhesives were developed using different methods.This thesis is mainly composed of the following three parts.In the first part,we used water-soluble salts(K₂CO₃and Na₂CO₃)to replace the template salts(KPF₆and KBF₄)that were difficult to remove in the synthesis of B21C7 crown ethers,and developed a method that only requires water washing to obtain high yield and high purity of B21C7s.The high efficiency of this method is proved by¹H NMR spectroscopy,and the accuracy and necessity of this method are proved by the crystal structure.In the second part,we combined the ferrocene group with the B21C7 crown ether to prepare a crown ether supramolecular adhesive with good adhesion on the hydrophilic surface,and made it lose its viscosity by simple oxidation.We found that the key to adhesion in this system is the formation of hydrogen bonds.After oxidation,the system is charged and can not form hydrogen bonds,and further losing the adhesion effect.Compared with crown ether supramolecular systems prepared with precious metals,the introduction of ferrocene functional groups not only reduces the cost,but also brings new functional directions for crown ether supramolecular systems.In the third part,two kinds of crown ether small molecule supramolecular polymers with good viscosity were prepared based on B21C7 through a simple dissolution-heating method.We have proved that the formation of this kind of supramolecular polymer system is based on hydrogen bonds through¹H NMR spectroscopy,crystal experiments and theoretical calculations.The strength of the hydrogen bond increases at low temperatures,so these two adhesives have good low temperature resistance.In the preparation process of these two supramolecular polymer systems,water is used as the solvent,which is pollution-free and low in cost,and provides a new idea for the preparation of small molecule supramolecular polymers.The preparation of benzo-21-crown-7 and its derivatives and two methods based on B21C7 and its adhesives reported in this thesis introduce a new idea for the preparation of crown ether rings and crown ether supramolecular adhesives,which is expected to be useful in the synthesis of crown ether supramolecular adhesives.