Study On Novel Calixarene Sensing And Switching Properties

There are many kinds of anions and cations in the natural environment and in organisms.Some of them play an important role in the metabolism and information transmission of organisms,while others are indispensable in industrial production.On the other hand,many anions and cations even if the concentration is very low will have adverse effects on the natural environment,causing great harm to human health.Therefore,detection of anions and cation is great significance.Fluorescence sensor has the advantages of high sensitivity,good selectivity,short response time,easy to directly observe,and convenient for real-time monitoring,etc.,which make up for the shortcomings of some other detection methods,thus attracting much attention.Calix[n]arene is the third generation of supramolecularhost compound after crown ether and cyclodextrin.As a new type of calixarenes,hetero-atom bridged calixarenes have different properties from classical Calix[n]arenes due to the existence of hetero-atoms with different polarity and larger cavity structure.According to many reports,Calix[n]arene is an excellent framework for constructing chemical sensors,and the derived chemical sensors have excellent performance and broad application prospects.In this paper,absorption spectrum,fluorescence spectrum,nuclear magnetic spectrum and other technical means were used to investigate the identification and sensing properties of anions,cations and small molecules of the new chemical sensors that based on Calix[4]arene or Thiacalix[4]arene,which were applied to the detection of biological and environmental related ions.The possibility of calixarene derivatives in the construction of solid fluorescent materials was also investigated.Studied three based on Calix[4]arene or Thiacalix[4]arene chemical sensors.sensor 1was designed ingenious,based on Thiacalix[4]arene in both ends of the introduction of various groups provides a role for anionic and cationic sites,make its ability to simultaneously detection Cu²⁺,Hg²⁺,Zn²⁺,I^-,and there are different mechanism and different signal response,has realized the multipurposesensor technology.2)sensor 2 is a amphiphilic fluorescence compound with Calix[4]arene as the lower rims of the molecular framework and modified aromatic ethyl group by nitrotriazole connecting carbazole upper rims.It is found that it has the double function of colorimetric recognition of alkali earth metal ions and anions.When reaction with earth metal ions Mg²⁺,Ca²⁺,Sr²⁺and Ba²⁺,the fluorescence intensity decreases.Due to different ion radius and binding force,different ions can be detected at different wavelengths and show different color changes.In addition,it is also found that the sensor 2 also exhibit the property of selective colorimetric recognition of F^-and AcO^-.Based on this phenomenon,we established a fast and convenient qualitative and semi-quantitative method to detect the above six ions through color change.3)sensor 3 is a Calix[4]arenederivative compound with two naphthalenediimide（NDI）groups.Due to its special structure,it interacts with aromatic compounds through with guest-to-host charge transfer force to obtain new solid fluorescent materials.In this chapter,the effects of sensor 3 and aromatic compounds are preliminarily studied,which opens up a new way for the design of calixarene sensors.