SYNTHESIS OF A FLEXIBLE MOLECULAR HETEROCAPSULE THAT REVERSIBLY BINDS GUEST MOLECULES
Edzna Garcia Ramirez, Linda Gutierrez-Tunstad.
California State University Los Angeles, Los Angeles, CA.
This study concerns the synthesis and characterization of a covalently linked and conformationally flexible resorcinarene heterocapsule that has the ability to trap guest molecules. Resorcinarene cavitands, container molecules with an enforced cavity, are of interest because of their 8 hydroxyl groups that can be functionalized to tailor guest binding. This field of supramolecular chemistry has become of great interest, because of the many potential applications of guest encapsulation such as in separation technologies and toxic remediation. Previous attempts to synthesize our heterocapsule met with difficulty because of the presence of many side products which made separation and purification difficult. We hypothesize that templation will facilitate the synthesis of our heterocapsule by driving its formation because of favorable interactions that stabilize the heterocapsule. Our heterocapsule will be synthesized from 2 different resorcinarene cavitands, a diquinoxaline monomethylene-bridged cavitand and a monoquinoxaline dimethylene-bridged cavitand, linked by a tetraazaanthracene bridge. Successful synthesis of the desired heterocapsule will be determined by nuclear magnetic resonance and high-resolution mass spectrometry. We expect to obtain a heterocapsule that can reversibly open and close in response to different stimuli such as changes in temperature, pH, and solvent to encapsulate guest molecules. Studying the physical properties of our heterocapsule will grant us vital information that will give us insight on how to control the capsulesâ€™ guest selectivity.