Synthesis And Properties Of Phenyl Group-based Molecular Cages

Supramolecular chemistry is an important branch as well as an important part of chemistry.Some organic cations,such as acetylcholine and creatinine cations,are of biological significance,so the high-intensity identification and high-sensitivity detection of these organic cations are very meaningful.Compared with macrocyclic host molecules,cage-shaped host molecules with permanent three-dimensional cavities have better encapsulation of guests and the synergy of multiple binding sites often makes the molecular cages more unique and excellent in the performance of molecular recognition.Although rigid molecular cages have good pre-organization capabilities in the process of molecular recognition,they require higher matching of structures between hosts and guests.The flexible molecular cages have good abilities of induced-fit,but the conformational changes during the host-guest binding process may lead to entropy penalty that reduce the binding strengh.Therefore,t he concepts of “pre-organization” and “induced-fit” are introduced into the molecualr cage design in this research.Baesd on the naphthol-based ether-oxygen molecular cages reported by our group,a phenyl-based ether-oxygen molecular cage was designed and synthesized.In this article,the synthesis and performance of the phenyl molecular cage was investigated in detail,for exemple,the design optimization of the precursor of the molecular cage.The phenyl-based molecular cage C2 was synthesized,then its detailed structural characterization was performed to reveal its three-dimensional structural information.In the section of host-guest chemistry study of molecular cage C2,the experimental results show that molecular cage C2 and organic cations have a relatively strong binding.By comparing with the naphthol-based molecular cages 2,3-NC and 2,6-NC reported by our group,the cavity charateristic and recognition characteristic of these three types of structurally similar molecular cages were discussed.Finally,the possibility of molecular cage C2 as a cation recerptor for the recognition and detection of biologically important organic cations is discussed.In order to study the flexibility of molecular cagess and the effect of ether-oxygen chains on the high-intensity recognition of organic cations.Derived from the successful preparation of ether-oxygen molecular cages C2,this article explored and synthesized the relatively rigid ester-based molecular cages C3 and C4,carring out structural characterizaiton and host-guest chemistry research.It was found that these molecular cages have poor recognition capabilities towards organic cations,this also reveals the uniqueness of the flexible ether-oxygen molecular cage in the recognition of organic cations.