Chemistry @ IU

Contact Information:

(812) 855-9364
dongwhan@indiana.edu
Chemistry A250C
Lee Group Website

Dongwhan Lee received B.S. and M.S. degrees with honors from Seoul National University, Korea, and was awarded his Ph.D. degree (2001) from Massachusetts Institute of Technology (MIT) under the guidance of Professor Stephen J. Lippard. Prior to joining Indiana University in 2003, he was a postdoctoral associate in the laboratory of Professor Timothy M. Swager at MIT.

Professor Lee's research program is broadly based on synthetic inorganic and organic chemistry of functional molecules and materials, with current focus on long-range mechanical coupling of artificial receptors, self-assembly and photophysics of discotic fluorophores, and conformational dynamics of shape-adaptive chemical architectures for molecular switching and sensing. The common theme threading through the group’s on-going research is designing and implementing cooperative mechanical coupling schemes that can amplify local structural distortions of small molecules to "readable" large-scale conformational changes at molecular and supramolecular level.

Research

Research in our laboratory currently centers around structurally pre-organized chemical architectures, in which the generation, transport, and decay of energy- or charge-carrying species are coupled to molecular recognition events. Presented with appropriate receptor units, these chemical platforms effectively transduce molecular recognition events to readable optoelectronic signal outputs. Synthetic organic and inorganic chemistry thus plays a pivotal role in our research program by providing well-defined d-p or p-p platforms having unusual structural as well as electronic properties. Detailed understanding of such hybrid systems is aided by crystallographic, spectroscopic, electrochemical, and theoretical methods. Fundamental scientific insights obtained from studies of these photo- or electroactive small molecules guide us in the exploration of their linearly conjugated systems (LCSs) of practical importance.

Electron Trafficking between Metal Clusters and Non-innocent Ligand LCSs. In naturally occurring systems, electronically coupled multiple metal centers work in concert to define favorable energy windows and minimize structural reorganizations accompanying electron transfer. Drawing inspiration from biology, we are investigating redox-active metal clusters placed within the charge conduits afforded by "non-innocent" ligand LCSs.

Loosely Held Polyaromatic Scaffolds for Conjugated Polymers (CPs). Site-isolation is a well-known trick in living systems, by which protein matrix gates access to buried binding sites. Emulating such naturally occurring architectural and functional properties, we are investigating 3-D macrocyclic hosts presenting precisely positioned functional group arrays. Grafted onto LCSs, these semi-rigid multidentate "ligands" serve as receptor units for chemical sensing.

Conjugation Beyond p-p: Heteroatom-Containing CPs. Transition metal-catalyzed coupling reactions allow entry into an elusive class of [n,p]-conjugated organic fragments having unusual optoelectronic properties. The oxidation potential of this underutilized functional motif is significantly lower than that of conventional LCSs, and its operational redox window is readily modified using modularly accessible electronic controller groups.

Publications

PubMed

Lee, H. Y.; Song, X.; Park. H.; Baik, M.-H.; Lee, D.* Torsionally Responsive C₃-Symmetric Azo Dyes: Azo–Hydrazone Tautomerism, Conformational Switching, and Application for Chemical Sensing. J. Am. Chem. Soc. 2010, 132, 12133–12144.

Liu, W.; Huang, W.; Pink, M.; Lee, D.* Layer-by-Layer Synthesis of Metal-Containing Conducting Polymers: Caged Metal Centers for Interlayer Charge Transport. J. Am. Chem. Soc. 2010, 132, 11844–11846.

Jo, J.; Lee, D.* Turn-On Fluorescence Detection of Cyanide in Water: Activation of Latent Fluorophores through Remote Hydrogen Bonds That Mimic Peptide ß-Turn Motif. J. Am. Chem. Soc. 2009, 131, 16283–16291.

Liu, W.; Pink, M.; Lee, D.* Conjugated Polymer Sensors Built on p-Extended Borasiloxane Cages. J. Am. Chem. Soc. 2009, 131, 8703–8707.

Lee, H. Y.; Jiang, X.; Lee, D.* Kinetics of Self-Immolation: Faster Signal Relay over a Longer Linear Distance? Org. Lett. 2009, 11, 2065–2068.

Jiang, X.; Lim, Y.-K.; Zhang, B. J.; Opsitnick, E. A.; Baik, M.-H.; Lee, D. "Dendritic Molecular Switch: Chiral Folding and Helicity Inversion" J. Am. Chem. Soc. 2008,130, 16812–16822.

Jiang, X.; Park, B. G.; Riddle, J. A.; Zhang, B. J.; Pink, M.; Lee, D. "Torsionally restricted tetradentate fluorophore: a swivelling ligand platform for ratiometric sensing of metal ions" Chem. Commun. 2008, 6028–6030.

Riddle, J. A.; Jiang, X.; Lee, D. Conformational dynamics for chemical sensing: simplicity and diversity. Analyst 2008, 133, 417-422.

Riddle, J. A.; Jiang, X.; Huffman, J.; Lee, D. Signal-Amplifying Resonance Energy Transfer: A Dynamic Multichromophore Array for Allosteric Switching. Angew. Chem. Int. Ed. 2007, 46, 7019-7022.

Jiang, X.; Vieweger, M. C.; Bollinger, J. C.; Dragnea, B.; Lee, D. Reactivity-Based Fluoride Detection: Evolving Design Principles for Spring-Loaded Turn-On Fluorescent Probes. Org. Lett. 2007, 9, 3579-3582.

Opsitnick, E.; Lee, D. Two-Dimensional Electronic Conjugation: Statics and Dynamics at Structural Domains Beyond Molecular Wires. Chem. Eur. J. 2007, 13, 7040-7049.

Lim, Y.-K.; Jiang, X.; Bollinger, J. C.; Lee, D., Molecular engineering of two-dimensional p-conjugation: Expected and unexpected photophysical consequences of simple particle-in-a-box approach. J. Mater. Chem. 2007, 17, 1969-1980.

Lim, Y.-K.; Wallace, S.; Bollinger, J. C.; Chen, X.; Lee, D., Triferrocenes Built on a C₃-Symmetric Ligand Platform: Entry to Redox-Active Pseudo-Triphenylenes via Chelation-Driven Stereoselection of Triple Schiff Bases. Inorg. Chem. 2007, 46, 1694-1703.

Jiang, X.; Bollinger, J. C.; Lee, D.; Two-Dimensional Electronic Conjucation: Cooperative Folding and Fluorescence Switching. J. Am. Chem. Soc. 2006, 128, 11732-11733.

Riddle, J. A.; Lathrop, S. P.; Bollinger, J. C.; Lee, D., Schiff Base Route to Stackable Pseudo-Triphenylenes: Stereoelectronic Control of Assembly and Luminescence. J. Am. Chem. Soc. 2006, 128, 10986-10987.

Jiang, X.; Bollinger, J. C.; Lee, D., How Bulky Is a Bulky Ligand: Energetic Consequences of Steric Constraint in Ligand-Directed Cluster Assembly and Disassembly. J. Am. Chem. Soc. 2005, 127, 15678-15679.

Riddle, J. A.; Bollinger, J. C.; Lee, D., Escape from a Nonporous Solid: Mechanically Coupled Biconcave Molecules. Angew. Chem. Int. Ed. 2005, 44, 6689-6693.

Jiang, X.; Bollinger, J. C.; Baik, M.-H.; Lee, D. Copper clusters built on bulky amidinate ligands: spin delocalization via superexchange rather than direct metal-metal bonding. Chem. Commun. 2005, 1043-1045.

Awards

• Alfred P. Sloan Research Fellowship, 2008-2010
• Indiana University Trustees Teaching Award, 2006-2007
• IU Outstanding Junior Faculty Award, 2006-2007
• NSF Faculty Early Career Development (CAREER) Award, 2006–2010
• IU Summer Faculty Fellowship, 2005

Highlights

IU chemist Dongwhan Lee elected a Sloan Fellow
The Alfred P. Sloan Foundation has awarded Indiana University Bloomington chemist Dongwhan Lee its 2008 Sloan Research Fellowship, a coveted $50,000 early-career grant. >> Full Story