The Daily Bulletin Archive

Dongwhan Lee, associate professor of chemistry at Indiana University, will visit Buffalo State to present his group research, "Making, Twisting, and Breaking Chemical Bonds: Mechanism-Based Design of Molecular Sensors and Switches," on Thursday, March 7, at 12:30 p.m. in Science Building 272. Before his talk, he will meet with Buffalo State students in Science and Math Complex 201 from 11:00 to 11:40 a.m. Lee received his Ph.D. in inorganic chemistry from MIT under the guidance of Stephan J. Lippard. After he completed postdoctoral training in Timothy Swager's lab at MIT, he joined Indiana University in 2003. The abstract of his talk appears below.

This seminar is sponsored by the Auxiliary Services Grant Allocation Committee, the Vice President for Student Affairs Office, and the Faculty-Student Association.

Abstract
An increasing number of functional materials are built with π-conjugated chemical architectures. The practical utility of such constructs derives from rich optical and electrochemical properties that are inherent to their extended electronic structures, and the ability to manipulate them by either covalent or noncovalent synthetic modifications. Taking inspirations from the mode of operation of certain transmembrane protein complexes, we have devised a simple mechanical coupling scheme that correlates torsional motions of multiple aromatic groups that interact through a symmetric array of hydrogen bonds. The assembly and disassembly of multiple noncovalent contacts within such branched π-conjugation result in a dramatic switching of fluorescence properties. Taking this concept a step further, we are currently exploring stimuli-responsive chromophores and receptors, in which restricted torsional motions along the π-conjugated molecular backbone can be exploited for reactivity-based detection of toxic molecules and ions. This presentation will discuss the advent of this chemistry, its current progress, and future developments.