Center for Bioinformatics at KU

As part of our public Seminar Series
http://bioinformatics.ku.edu/seminars

Sep 21, Wed, 2005
10:00am - 11:00am, Pine Room, KU Union

Ping Yang

Intramolecular Hydrogen Bonding Network in myo-inositol phosphates and Surface Passivation of Quantum Dots

State-of-the-art computational methods allow studying molecular structures and interactions of biomolecules and materials at the atomic level. I will present two studies, firstly a problem of biological interest and secondly a study of quantum dots relevant to the materials community.

The first study demonstrates the pivotal role that the intramolecular hydrogen-bonding network plays in the determination of the conformation of biologically significant compounds, which contain both phosphate and hydroxyl groups. myo-Inositol 2-monophosphate (Ins(2)P1) is a model system for studying the dependence of hydrogen bonding on deprotonation degree, solvent effects and counter-ion effects. We found that, a novel four-center pattern of hydrogen bonding is formed and intramolecular proton transfer across a low barrier hydrogen bond can occur between hydroxyl and charged phosphate groups.

The second study is to understand the surface structure of colloidal CdSe quantum dots (a.k.a. semiconductor nanocrystals) and the passivating role of capping ligands. Quantum dots have stimulated a great deal of research and technical interest in recent years due to their attractive properties of chemical stability and tunability of their photophysical properties. We apply Quantum Chemistry methods, including semiempirical, wavefunction approaches and Density Functional Theory to systematically study the suitability of methods, the passivation impact of ligands on cluster structure and the affinities of different ligands, such as trioctylphosphine oxide, trioctylphosphine and amines.