Synthetic And Assembly Of Crown Ethers Containing Oxadiazole

Supramolecular chemistry is one of the most attractive fields in chemistry science, lifescience and materials science. As the first general supramolecular compounds, crownethers have received particular interest of numerous chemists for their easyfunctionalization, controllable cavity and strong binding properties towards cations, anions,neutral molecules and molecular assembly in recent years. Benzo-oxadiazole system is ahighly sensitive strong fluorescent groups, and it is not only served as the fluorescenceprobe, but also coordinate with the metallic ion directly. Therefore, compounds containingoxadiazole have attracted wide attention. Here we synthesized macrocyclic crown ethercontaining oxadiazole, aiming to study the methods of synthesis and self-assemblybehavior.The main contents include the following main points:1. The general aspect of supramolecular chemistry was described briefly. Synthesismethods, new progress and important achievements on molecular recognition andself-assembly of crown ethers and their derivatives were reviewed.2. The reasonable experimental programs are designed. Experimental conditions forsynthesis of1+1and2+2products are explored, eleven kinds of crown ethers containingoxadiazole are synthesized and isolated and t two of these compounds have been confirmedby X-ray structure analysis. All intermediates and products are characterized by1H NMR, MS,IR, UV.1H NMR、IR、MS spectra are analyzed and their structures are confirmed3. Different complexes have been synthesized by the reaction of macrocycles crownether â…ª with NaI, KI, sodium picrate, potassium picrate, NaClO₄, KClO₄. Thesecomplexes are characterized by1H NMR、IR、UV spectral. The results show that theassembly of crown ether â…ª with Na⁺or K+have been formed and the coordination modeof benzo-15-crown-5with Na⁺and K⁺was conformed in different ways. The complexratio of benzo-15-crown-5to Na⁺was1:1. The sandwich complexes of benzo-15-crown-5with K⁺was formed, and the intermediate ring with K+formed1:1complex. The SEM,TEM, AFM spectrum further revealed the potassium ions with crown ethers by forming1:2sandwich complexes, which are assembled into a linear structure.