Design, Synthesis & Studies On Recognizing Properties Based On Functional Calix[4] Arenes By Click Chemistry

Calixarenes, the third generation supramolecular, are more liable to chemical modification by incorporating the functional groups, compared to the crown and cyclodextrin. Therefore, calixarenes have been shown to be useful scaffolds for highly preorganized supramolecular receptors, which are widespread applied in number of research fields including molecular recognition, nano materials, self-assembly and catalyst. With special physical and chemical properties, calixarenes modification and versatile applications have attracted great interests in home and abroad. Thus, a study of rational design, synthesis and extension of applied fields is an important and useful topic. In this thesis, by a combination of functional groups such as fluorophore, binding bites with calixarenes, we designed novel calixarene-based polytoptic systems and synthesized a series of calix[4]arene detivatives via click chemistry. Their recognition and sensing abilities toward various metal ions, anions and neutral guests were studied. In addition, metal nanoparticles and self-assembled monolayer (SAMs) have a wide and potential application in many areas, especially in designing and fabricating new functional materials. Hence, we constructed the calix[4]arene detivatives modified silver nanoparticles and SAMs. And also, their recognition properties were studied. Fortunately, we have received innovative research results.The main contents are as follows:1. The novel pyridyl-appended calix[4]arenes, which can selectively bind Fe+, were synthesized via click chemistry. The calix[4]arenes were employed to synthesize silver nanoparticles with a distinct colorimetric response to Fe3+. The Fe3+ induced color change was supported by the complexation mode of the pyridyl-appended calix[4]arene with Fe3+ at the molecular level.2. A calix[4]arene lipoic acid (â…¢-3) was synthesized by click chemistry. It was immobilized on Au surfaces via self-assembly to offer Self-Assembled Monolayers (â…¢-3/SAMs). The wettability ofâ…¢-3/SAMs toward carbamates were investigated. It was found that theâ…¢-3/SAMs showed wettability response for methomyl through the transition from hydrophobicity to hydrophilicity. Based on the UV and NMR spectra in solution, we further studied the binding model which indicated the possible recognition process forâ…¢-3 toward methomyl on the surface.3. A series of triazole-modified calix[4]crowns, containing hard and soft ion binding sites were synthesized in good yields via click chemistry. A convenient and efficient strategy for the synthesis of calixcrowns was developed. X-ray diffraction data further determined the structure of calix[4]crowns. Their recognition abilities toward alkali metal or transition metal cations were investigated by picrate extraction experiments.4. Novel anthraquinone-modified calix[4]arenes V-3 were synthesized by click chemistry andâ…¤-3c exhibited selective fluorescent enhancement in the presence of Ca2+. The enhanced fluorescence was further quenched by F- ion. Thus, the potential Ca2+ and F- ions switched INHIBIT logic gate has been constructed.5. Four fluorescent calix[4]arenes with naphthyl groups were designed and synthesized by click chemistry and their recognition abilities toward metal ions were studied. It was found that they both exhibited selective recognition toward Cu2+ among transition metal cations with fluorescence quenching. Among them, the calix[4]arene containing the diethylene glycol chains, showed the highest selectivity for Sr2+ among alkali earth metal ions, while the calix[4]arene containing the tertethylene glycol chains, showed the highest selectivity for Sr2+ and Ba2+. The results revealed that the ethylene glycol chains can tune the cooperating complexation with the metal ion. The complexation mode was investigated by the 1H NMR spectra. On the other hand, they exhibited high binding affinity and selectivity toward p-nitroaniline driven by H-bonding and hydrophobic interactions. However, the sensitivity of the fluorescent calix[4]arene toward other anilines including aniline, o-chloroaniline, p-chloroaniline, o-nitroaniline, m-nitroaniline, p-nitroaniline are negligible. The 1H NMR and computational calculations revealed the possible mechanism.6. Based on the study of the six chaper, four fluorescent calix[4]arenes with binaphthyl groups were designed and synthesized by click chemistry and their recognition behaviors toward various ions were studied. The results indicated that they both exhibited selective recognition toward Cu2+. Furthermore, tunable selective fluorescent sensing of Ba2+ was realized based on calix[4]arene containing the tertethylene glycol chains.7. Biscalix[4]arenes:click synthesis and selective recognition toward metal ions by UV-vis spectral. It was found that VI-3a-b showed selective recognition toward Ag+ and Cd2+, and VI-3c-d had high selectivity for sensing of Cu2+. The complexation mode was investigated by the 1H NMR spectra.