Effect of temperature and substitution on cope rearrangement: A symmetry perspective

Inbal Tuvi-Arad, Tamás Rozgonyi, A. Stirling

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Many reactions feature symmetry variation along the reaction path on the potential energy surface. The interconversion of the point group symmetry of the stationary points can be characteristic of these processes. Increasing the temperature, however, leads to the loss of symmetry in its traditional yes-no language. We find that in such cases the instantaneous distance of the molecular structure from its symmetric counterpart is a suitable collective variable that can describe the reaction process. We show that this quantity, the continuous symmetry measure (CSM), has a positive linear relationship with temperature, implying that even highly symmetric molecules should be considered as asymmetric above 0 K. Using ab initio molecular dynamics, we simulate the temperature-induced Cope rearrangements of several fluxional molecules and employ different CSMs to follow the reaction progress. We use this methodology to demonstrate the validity of important concepts governing these reactions: Woodward-Hoffmann rules and TS aromaticity. Statistical analysis of the CSM distributions reveals that ligands connected to the carbon frame have profound effect on the reaction course. In particular, our results show that lower temperatures tend to enhance the differences between the TS-stabilizing effect of the substituents.

Original languageEnglish
Pages (from-to)12726-12733
Number of pages8
JournalJournal of Physical Chemistry A
Volume117
Issue number48
DOIs
Publication statusPublished - Dec 5 2013

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Substitution reactions
substitutes
symmetry
Point groups
Temperature
Potential energy surfaces
Molecules
temperature
Crystal symmetry
command service modules
Molecular structure
Molecular dynamics
Statistical methods
Carbon
Ligands
statistical analysis
molecules
molecular structure
potential energy
methodology

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Effect of temperature and substitution on cope rearrangement : A symmetry perspective. / Tuvi-Arad, Inbal; Rozgonyi, Tamás; Stirling, A.

In: Journal of Physical Chemistry A, Vol. 117, No. 48, 05.12.2013, p. 12726-12733.

Research output: Contribution to journalArticle

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