DFT Computational Analysis of Photophysical (Linear and Non-linear) and Photochemical Parameters for the Design of New Coumarins as Photocatalyst

Abstract

Photocatalysis promotes eco-friendly reactions under mild conditions, and among photocatalytic agents are dyes, which have good redox potential in their excited states. The aim of the current contribution was to design a novel series of coumarins based on DFT analysis of their photochemical properties. The coumarin amide group serves as a linking group to cinnamic acid, allowing for electron delocalization throughout the system and the stabilization of the anionic and cationic species. An electronic structure analysis was performed by calculating vertical excitations and emissions, obtaining conceptual DFT chemical descriptors and nonlinear optical parameters (e.g., first static hyperpolarizability β). The novel coumarin derivatives display a reduction in the HOMO–LUMO energy gap from 6.11 to 4.2 eV, large oscillator strength (1.93), efficient nonlinear optical behavior, and excellent redox potential. Hence, they are promising compounds for photocatalytic activity.

Graphical Abstract

The present work shows a series of computational parameters that can be considered for the design of a molecule with potential photocatalytic activity, evaluating in this instance a series of new coumarins, promising from the computational point of view