Isolated Quantum Systems – Atomically Resolved Gas Phase Reaction Dynamics
This research program is dedicated to exploring molecular reaction dynamics and photophysics of molecules under isolated gas phase conditions. The overall objective is to go from well defined small molecule systems all the way to biological systems under collision free conditions to isolate the effect of the surrounding bath on the many body potential defining chemical and biological processes. A new generation of ultrabright electron sources are being developed specifically for gas phase studies in which both velocity mismatch and number density problems of gas phase diffraction studies will be solved to a great extent. We expect to have 100 fs time resolution with atomic resolution, with resolution approaching the highest accuracy attained with gas phase electron diffraction (from which most bond lengths are determined to 3 significant figures). In addition to the new electron source technology, we have also developed a new means to introduce proteins into the gas phase without fragmentation. We expect to be able to go in a systematic way from well defined molecular systems to protein analogues, to actual protein systems. In this respect, this work is paving the way to true single molecule structure determination that will explicitly take advantage of the >106 higher scattering cross section of electrons relative to x-rays, as well as new advances in detector technology to approach single electron detection and exploit recent advances in image reconstruction.
Some of the key problems to be explored will include classic chemical reactions from bond dissociation, ring opening reactions, isomerization, and charge transfer processes, in which the same molecular moiety will be studied in situ in solution phase using the recent development of nanofluidics (vide infra) for electron probes. The comparison of the same system with and without solvent will give an atomic level view of the effect of solvation dynamics on reaction coordinates – one of the main objectives of physical chemistry.