Determination Of Spectroscopically-structural Connection In The Pyridinium Series To Probe London Dispersion Forces

Gorbachev, Vladimir

Permalink

https://hdl.handle.net/2142/111293 Copy

Description

Title

Determination Of Spectroscopically-structural Connection In The Pyridinium Series To Probe London Dispersion Forces

Author(s)

Gorbachev, Vladimir

Contributor(s)

• Chen, Peter
• Miloglyadova, Larisa
• Tsybizova, Alexandra

Issue Date

2021-06-24

Keyword(s)

Action spectroscopy (incl. PE, PD, PI, LIR)

Abstract

\begin{wrapfigure}{l}{0pt} \includegraphics[scale=0.2]{Repulsive_or_atractive.eps} \end{wrapfigure} London dispersion, the attractive part of the van der Waals potential, is an omnipresent force in molecules. However, even a cursory glance at presumably driven by the London dispersion two systems from references\footnote{Muller, P. \textit{Pure and Applied Chemistry.} \textbf{1994}, \textit{66}, 1077.}$^{,}$\footnote{Lyttle, M. H.; Streitweiser, A. Jr.; Kluttzt, R. Q. \textit{J. Am. Chem. Soc.} \textbf{1981}, \textit{103}, 3232.} gives curiously conflicting answers, raising a legitimate question: are steric interactions repulsive or attractive? \\ To address this issue a new molecular torsion balance was proposed.\footnote{Tsybizova‡, A.; Fritsche‡, L.; Gorbachev‡, V.; Miloglyadova. L.; Chen, P. \textit{J. Chem. Phys.} \textbf{2019}, \textit{151}, 234304.} Obtained systematic CIVP-spectroscopic pattern – structural connection in the series of large molecules, \textit{o,o}-disubstituted pyridiniums, could be used as an effective tool to explore London dispersion experimentally. Analysis of the conformer spaces: energies, frequencies, geometries as well as an extensive data set: X-ray and solid-state FT-IR data unambiguously link the gas-phase fingerprint with well-determined structures for all test-compounds in the series. Even among homologues, London dispersion significantly affects the resulting geometry starting from a change in the pendant substituents' relative position with respect to each other and ending with a total change of conformation. Remarkably, for the pyridinium featuring the highest DED-properties in the series, dispersion corrected methods appear to overestimate the magnitude of London dispersion forces, which leads to the principal improper assignment of the conformer in contradiction to the experimental data.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Permalink

http://hdl.handle.net/2142/111293

DOI

10.15278/isms.2021.RM12

Owning Collections