Synthesis And Characterization Of Some Building Blocks For The Construction Of Stimuli-responsive Supramolecular Structures

Molecular recognition is the chemical basis of many biological processes and biological phenomena, and is one of the most important components of supramolecular chemistry. Effective control of the molecular recognition processes by external stimuli may afford a deeper understanding of the nature of the processes and open ways to their potential applications, such as design of novel intelligent materials, new sensors and molecular machines, etc. Therefore, studies on the control of molecule recognition have received considerable attention during the last 20 years.In theory, any physical, chemical or biological signals may be employed to control the recognition processes. Among them, photochemistry, pH, temperature and electrochemistry are the mostly studied ones. Compared to other methods, electrochemical approach is most attractive since it does not contaminate the systems to be studied, and is easy to be performed. Therefore, it has become popular in the studies of controllable molecular recognition in recent years.Host-guest interaction is the mostly studied electrochemically controllable molecular recognition processes. The control is based upon the fundamental phenomenon that the interaction strength strongly depends upon the oxidation state of the host or the guest, and thereby the gain or loss of an electron by a host or a guest molecule will modify the stability of a host-guest complex.As an important kind of host, cyclodextrin can form stable inclusion complexes with less polar molecules (guests) that fit tightly inside the cyclodextrin cavity. This host-guest interaction is affected not only by guest's polarity and size but also by the environment of medium such as temperature, pH, polarity and radiative stimulation. Consequently, the interaction between host and guest can be tuned by varing these conditions.Based upon this methodology, a series of building blocks was designed and prepared in the present study. The host-guest interactions between one of the prepared di-guest type cross-linker and β-cyclodextrin have also been studied. The insight obtained from the studies can be useful for the design and preparation of novel supramolecular structures and smart soft materials.First, ferrocenoyl chloride and N,N'-bis(ferrocenoyl)diaminoethane have been prepared with ferrocene carboxylic acid and 1,2-diaminoethane as the starting materials. The...