Application of Inverse Design Approaches to the Discovery of Nonlinear Optical Switches.

Molecular switches, in which a stimulus induces a large and reversible change in molecular properties, are of significant interest in the domain of photonics. Due to their commutable redox states with distinct nonlinear optical (NLO) properties, hexaphyrins have emerged as a novel platform for multistate switches in nanoelectronics. In this study, we employ an inverse design algorithm to find functionalized → redox switches with maximal βHRS contrast. We focus on the role of core modifications, since a synergistic effect with -substitutions was recently found for the -based switch. In contrast to these findings, the inverse design optima and subsequent database analysis of -based switches confirm that core modifications are generally not favored when high NLO contrasts are targeted. Moreover, while push-pull combinations enhance the NLO contrast for both redox switches, they prefer a different arrangement in terms of electron-donating and electron-withdrawing functional groups. Finally, we aim at designing a three-state →→ switch with a similar NLO response for both ON states. Even though our best-performing three-state switch follows the design rules of the -based component, our chemical compound space plots show that well-performing three-state switches can be found in regions shared by high-responsive and structures.