Computational Design of Boron-Free Triangular Molecules with Inverted Singlet-Triplet Energy Gap

TL;DR

This paper reports the computational design of novel boron-free triangular molecules with an inverted singlet-triplet energy gap, emphasizing the importance of excited-state geometry optimization for optoelectronic applications.

Contribution

It introduces a new class of cyclic oligomer molecules with localized electronic conjugation, advancing the understanding of inverted singlet-triplet gaps in organic molecules.

Findings

Identification of molecules with inverted singlet-triplet gaps

Significance of excited-state geometry optimization

Potential applications in OLED technology

Abstract

A novel, computationally designed, class of triangular-shape organic molecules with an inverted singlet-triplet (IST) energy gap is investigated with the aid of ab initio methods of electronic structure theory. The considered molecular systems have a form of cyclic oligomers and their common feature is electronic conjugation localized along the molecular rim. Analysis of vertical transition energies from the electronic ground state, as well as from the lowest excited singlet and triplet states of selected molecules, is conducted. The results underscore the significance of optimizing excited-state geometries in theoretical models to accurately describe the optoelectronic properties of the IST molecules, particularly in relation to their applications in OLEDs.