Microsolvation and the effects of non-covalent interactions on intramolecular dynamics

Foguel, Lidor

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https://hdl.handle.net/2142/96904 Copy

Description

Title

Microsolvation and the effects of non-covalent interactions on intramolecular dynamics

Author(s)

Foguel, Lidor

Contributor(s)

• Vaccaro, Patrick
• Vealey, Zachary

Issue Date

2017-06-21

Keyword(s)

Clusters/complexes

Abstract

Physicochemical processes brought about by non-covalent interactions between neighboring molecules are undeniably of crucial importance in the world around us, being responsible for effects ranging from the subtle (yet precise) control of biomolecular recognition events to the very existence of condensed phases. Of particular interest is the differential ability of distinct non-covalent forces, such as those mediated by dispersion-dominated aryl ($pi$-$pi$) coupling and electrostatically-driven hydrogen bonding, to affect unimolecular transformations by altering potential surface topographies and the nature of reaction coordinates. A concerted experimental and computational investigation of “microsolvation” (solvation at the molecular level) has been undertaken to elucidate the site-specific coupling between solute and solvent degrees of freedom, as well as attendant consequences for the efficiency and pathway of intrinsic proton-transfer dynamics. Targeted species have been synthesized in situ under “cold” supersonic free-jet expansion conditions (textit{T}$_{rot}$ $approx$ 1-2K) by complexing an active (proton-transfer) substrate with various ligands (e.g., water isotopologs and benzene derivatives) for which competing interaction mechanisms can lead to unique binding motifs. A series of fluorescence-based spectroscopic measurements have been performed on binary adducts formed with the prototypical 6-hydroxy-2-formylfulvene (HFF) system, where a quasi-linear intramolecular O–H···O bond and a zero-point energy that straddles the proton-transfer barrier crest synergistically yield the largest tunneling-induced splitting ever reported for the ground electronic state of an isolated neutral molecule. Such characteristics afford a localized metric for unraveling incipient changes in unimolecular reactivity, with comparison of experimentally observed and quantum-chemical predicted rovibronic landscapes serving to discriminate complexes built upon electrostatic (hydrogen-bonding) and dispersive (aryl-coupling) forces.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/96904

DOI

https://doi.org/10.15278/isms.2017.WD02

Copyright and License Information

Copyright 2017 Lidor Foguel

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