Chemistry
Dr. Mintu Porel
Cornell University, Ithaca, New York
Abstract: Supramolecules and macromolecules are two important classes of molecular entities of profound interest. Molecules are held-together by non-covalent interaction in supramolecular assembly whereas the building blocks are covalently bonded to build a macromolecule. In this seminar, I will introduce a new supramolecular assembly and a novel class of macromolecules and their widespread applications.
We have explored a water-soluble synthetic supramolecular host named as "octa acid" (OA) as a reaction cavity for manipulating photochemical and photophysical properties of organic molecules. Most of the guest molecules are enclosed within a capsule made of two OA molecules. The interior of OA capsule is benzene-like nonpolar despite the complex being present in water. Additionally, the confined guests are not isolated but can communicate with the molecules in solution. This part will be discussed with photoinduced electron transfer from the donor incarcerated within OA-capsule to the acceptor free in solution as well as to the semiconductor (e.g. TiO2).
In the second half, I will talk about a novel class of sequence-defined polymers, named as oligothioetheramides (oligoTEAs) that look like the biopolymers in our body, but are instead created with synthetic molecules designed in the lab. Herein, I will demonstrate a unique strategy for rapid synthesis of oligoTEA. By creating these synthetic polymers in a controlled manner, we can precisely tune their size, composition and properties. With an eye towards biological applications, various bioactive side chains were introduced into the primary sequence. The effects of these side chain and backbone groups on the chemical properties and biological function will be discussed. Finally, I will propose a novel “support-free iterative” strategy to build a new class of architecturally diverse functional materials in a rapid, scalable and economic way and their potential applications in biomedical and material sciences.
