Synthesis And Property Of Heterosupramolecular Capsule Based On Hamilton Receptor And Cyanuric Acid Guest Interaction

Calixarenes have become the third generation of host molecules in the area of supramolecular chemistry, it is dependent on their synthetic simplicity and easy functionalization. Moreover, the unique cavity of calixarene is helpful to build the supramolecular capsule. In the last twenty years, various functional groups have been intruduced to calixarenes by many chemists. They build the new supramolecular compounds-supramolecular capsules based on the weakly intermolecular interactions of self-complementary functional groups. Most of these supramolecular capsules are assembled by the same kind of monomer molecules with self-complementary hydrogen bonding sites. However, the research on heterodimer capsules is rarely reported. In this case, two different hemispheres which form the heterodimer capsules can lead to the asymmetric cavity, which induces the asymmetric and other unique properties of the guest molecules in the cavity.Hamilton receptor/cyanuric acid recognition motif shows stable ADA?DAD sextuple hydrogen bonds with the binding constant of 106 M-1. Therefore, this hydrogen bonding system is widely used in the area of supramolecular chemistry. However, this recognition motif has never been involved in construction of capsules. In this paper, we successfully synthesized the calix[4]arene monomer with Hamilton receptor units, and cyanuric acid units, respectively, then investigated their behavior of self-assembly and guest encapsulation.It is shown by 1H NRM spectra that, in the presence of excessive pyridine oxide, two hemispheres assembled to heterodimer capsule by the twenty-four hydrogen bonds of hamilton receptor/cyanuric acid. The NH proton signal peaks of hamilton receptor and cyanuric acid shifted downfield.