Predicting mechanochemical reactivity with the method of Constrained Geometries Simulate External Force

14 September 2022, Version 1
This content is a preprint and has not undergone peer review at the time of posting.

Abstract

Mechanochemistry is a fast-developing field of interdisciplinary research with a growing number of applications. Therefore, many theoretical methods have been developed to quickly predict the outcome of mechanically induced reactions. Constrained geometries simulate External Force (CoGEF) is one of the pioneering methods in this field. It is easily implemented and can be conducted with most DFT codes. However, recently, we observed totally different predictions for model systems of epoxy resins in different conformations and with different density functionals. To better understand the conformational and functional dependence in typical CoGEF calculations we present a systematic evaluation of the CoGEF method for different model systems covering homolytic and heterolytic bond cleavage reactions, electrocyclic ring opening reactions and scission of non-covalent interactions in hydrogen-bond complexes. From our calculations we observe that many mechanochemical descriptors strongly depend on the functional used, however, a systematic trend exists for the relative maximum Force. In general, we observe that the CoGEF procedure is forcing the system to high energetic regions on the molecular potential energy profiles, which can lead to unexpected and uncorrelated predictions of mechanochemical reactions. This is questioning the true predictive character of the method.

Keywords

COGEF
Density Functional Theory (DFT)
mechanical force
mechanochemistry
molecular fracture
mechanical bond scission
mechanoradicals

Supplementary materials

Title
Description
Actions
Title
Supporting Information
Description
Summary of the unrestricted and restricted CoGEF procedures, summary of additional CoGEF calculations for compound 9 with the restricted CoGEF procedure (file type: PDF) All simulation data is available via ZENODO (DOI: 10.5281/zenodo.6948605)
Actions

Supplementary weblinks

Comments

Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.