Work

Converting Second‐Order Saddle Points to Transition States: New Principles for the Design of 4π Photoswitches

Year: 2024

Type: article

Abstract: Molecular photoswitches have demonstrated potential for storing solar energy at the molecular level, with power densities comparable to commercial batteries and hydroelectric energy storage. However, development of efficient photoswitches is hindered by limitations in cyclability and optical properties of existing materials. We here demonstrate that certain limitations in photoswitches based on electrocyclizations stem from the issue of controlling competition between Woodward-Hoffmann allowed and forbidden pathways. Our approach moves beyond the traditional view of activation barriers and reveals that second-order saddle points are crucial in dictating the competition between disrotatory and conrotatory pathways. These insights suggest new opportunities to manipulate the competition between these pathways through geometric constraints, fundamentally altering the connectivity of the potential energy surface. Our study also emphasizes the necessity of multi-reference methods and the need to conduct higher-dimensional explorations for competing pathways beyond photoswitch design.

Source: ChemPhysChem

DOI: 10.1002/cphc.202400786

Authors: Amir Mirzanejad, Lukas Muechler

Institution: Pennsylvania State University

Language: English

Topic: Photochromic and Fluorescence Chemistry

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,330

Funders: U.S. Department of Energy, Office of Science, Basic Energy Sciences