Thirty-Ninth Annual Frederick Kaufman Memorial Lecture Day 1

About this event

This year's Kaufman Memorial Lecture speaker is Prof. Mark Johnson , Yale University.

Title : Decoding the spectral signatures of “excess” proton speciation and transport kinetics in water with cryogenic ion chemistry and spectroscopy

Abstract : Understanding the properties of protons released into water at the molecular level has proven to be surprisingly challenging. This occurs because the positively charged entity that is formed occurs with variable spatial extent surrounding a defect in the interlocking OH bonds that knit together the extended hydrogen bonded network. This talk will describe how these local structures were captured and characterized using specially designed experimental methods to isolate the vibrational spectra of specific molecular compositions at very low temperature. These instruments integrate cryogenic ion trapping techniques with mass spectrometry and laser spectroscopy. Once the structural information encoded in cold ion spectra was established, a second generation of experiments, one that is currently on-going, evolved that follow the kinetics of long-range proton migration, mediated by a precisely controlled number of water molecules. Simulations of this process, now anchored to experimental benchmarks, provide a microscopic picture of the “proton relay” paradigm envisioned long ago by Grotthuss and widely invoked to rationalize charge transport in aqueous media.

Bio : This year's speaker will be Prof. Mark Johnson, Arthur T. Kemp Professor of Chemistry at Yale University. Johnson is known for the development and exploitation of experimental methods that capture and structurally characterize transient chemical species, such as reaction intermediates, using cryogenic ion chemistry in conjunction with multiple resonance laser spectroscopy. His contributions have been recognized through multiple awards including the APS Plyler Prize in Molecular Spectroscopy, the ACS Irving Langmuir Award in Chemical Physics, and membership in the National Academy of Sciences.

See more of Dr. Johnson's research on his website : https://jlab.chem.yale.edu /