Ultrastable Self-Cross-linkable Electro-Optic Materials Based on a Bisanthracene Scaffold

Abstract

In this study, self-cross-linkable chromophores TD1 and TD2 were designed and synthesized, both of which use aniline derivatives as the donor, isophorone-derived structures as the bridging unit, and trifluoromethyl-substituted TCF (CF₃-TCF) as the acceptor. Among them, TD1 was functionally modified with cross-linkable alkynyl and azide groups at the donor end and bridging end, respectively, while TD2 was introduced with bianthracene groups and acrylate groups. After cross-linking, the nonlinear optical coefficients (r₃₃) of TD1 and TD2 were 191 and 141 pm/V, respectively. Benefiting from the introduction of the bianthracene structure in TD2 molecules, its thermal stability was significantly superior to that of TD1, with a glass transition temperature (T_g) of 111.06°C, which was 50.68°C higher than that of TD1. The glass transition temperature of cross-linked TD2 was as high as 195.32°C, an increase of 51.97°C compared with TD1. After constant temperature heating at 85°C for more than 500 h, the cross-linked and poled TD2 electro-optic thin film could still retain 99.75% of its initial r₃₃ value, indicating that its thermal stability was significantly improved compared with TD1. Therefore, TD2 is expected to be applied in advanced electronic materials under high-temperature conditions.