Download Document 8624478

Tuesday,
April 5, 2016
11:00 am
Room 1315
Chemistry Building
From Quantum State Resolved Collision Dynamics at GasLiquid Interfaces to
Thermodynamics/Kinetics of RNA Folding at the Single
Molecule Level
Professor David J. Nesbitt
JILA, National Institute of Standards and Technology
and University of Colorado, Boulder
Department of Chemistry and Biochemistry
Chemists have been amazingly successful with the manipulation of complicated molecular systems, whereas to a physicist, even simple molecules can seem overwhelmingly complex. Physical chemists are blessed (or cursed) with a dual scientific personality. We are attracted to real world chemical systems and yet are often not satisfied posing questions without the requisite rigor to hope for fundamental answers. This talk will provide an overview of work in my labs that attempts to address complex molecular systems but with a physical chemist’s eye toward finding the underlying simplicity. This talk will focus on recent results from our labs sampling the following two areas: 1) The first area involves molecular and quantum state level exploration of inelastic and reactive collision dynamics at the gas-­‐liquid interface, which we study by generating supersonic beams of jet cooled molecules, “splashing” them off liquid or liquid-­‐mimetic (e.g., self assembled monolayer) surfaces in high vacuum, and probing the internal quantum state and full 3D momentum distributions of the recoiling product molecules with a suite of IR, UV laser spectroscopies. 2) The second topic will be in biophysics on the use of confocal microscopy, fluorescence resonance energy transfer (FRET), and time correlated single photon counting methods to explore the single molecule kinetics and thermodynamics of RNA folding, in particular probing the effects of microscopic viscosity and molecular “crowding” on tertiary and secondary structure motifs responsible for “docking” single stranded RNA oligomers into biochemically competent 3D structures. In each of these topics, the focus will be on simple physical pictures that help explain and interpret the underlying chemical physics. Refreshments will be available prior to the seminar at 10:45 a.m. outside room 1315
Graduate Students can meet with the speaker in Room 8305F at 1:00 pm