Work

The effect of zero‐point energy in simulating organic reactions with post‐transition state bifurcation

Year: 2022

Type: article

Abstract: Ambimodal reactions involve a single transition state leading to multiple products. To assess the ratio of the bifurcation products, quasiclassical trajectories (QCTs) are initiated from transition state geometries that are randomly sampled using the zero‐point energy (ZPE) plus thermal energy of a molecule's vibrational modes. However, in the QCTs, the influence of ZPE percentage in the resulting bifurcation ratio and time gap between formation of bonds is not well understood. To benchmark the effect of varying the percentage of the molecules' inherent ZPE used in the simulation, three organic reactions with distinct mechanisms that all display post‐transition state bifurcation were selected. The three reactions studied include an intramolecular [6 + 4]/[4 + 2] cycloaddition, an asynchronous nitrene insertion, and an S N 2/addition to a carbonyl on an α‐bromoketone. These reactions encompass various modes of bond formation and cleavage, offering a broad view of the influence of ZPE scaling in evaluating the product ratio resulted from post‐transition state bifurcation. Exploring means of tuning selectivity in simulation enables development of more accurate organic reaction modeling for synthetic prediction. This work will establish a basis for future QCT studies of organic reactions.

Source: Journal of Physical Organic Chemistry

DOI: 10.1002/poc.4322

Authors: Matthew T. Tremblay, Zhongyue J. Yang

Institution: Vanderbilt University

Language: English

Topic: Advanced Physical and Chemical Molecular Interactions

Subfield: Physical and Theoretical Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: green

Funder: Vanderbilt University

Award: G2837239461