Spin Polarization and Dispersion Effects in Emergence of Roaming Transition State for Nitrobenzene Isomerization

TL;DR

This study uses first-principles calculations to explore the atomic-level structure and electronic properties of roaming transition states in nitrobenzene isomerization, highlighting magnetic coupling and dispersion effects.

Contribution

It provides new insights into the electronic structure and stability factors of roaming transition states in nitrobenzene, advancing understanding of roaming mechanisms.

Findings

Antiferromagnetic coupling between roaming fragments.

Dispersion significantly influences TSR stability.

Electronic structure insights into roaming transition states.

Abstract

Since roaming was found as a new but common reaction path of isomerization, many of its properties, especially those of roaming transition state (TSR), have been studied recently on many systems. However, the mechanism of roaming is still not clear at the atomic level. In this work, we used first-principles calculations to illustrate the detailed structure of TSR in an internal isomerization process of nitrobenzene. The calculations distinctively show its nature of antiferromagnetic coupling between two roaming fragments. Moreover, the effect of dispersion is also revealed as an important issue for the stability of the TSR. Our work provides a new insight from the view of electronic structure towards the TSR and contributes to the basic understanding of the roaming systems.