Optimizing combination between thianthrene and benzophenone toward efficient room-temperature phosphorescence and oxygen sensing

Abstract

Purely organic room-temperature phosphorescence (RTP) materials show broad prospects in various applications due to their characteristics such as stimuli-responsiveness and high exciton utilization. A key challenge for improving the performance of purely organic RTP materials lies in suppressing non-radiative decay while enhancing spin-orbit coupling (SOC). To this end, we systematically combined benzophenone (BP) with thianthrene (TA) at different modification sites and with varying numbers of substituents, creating a class of high-efficiency RTP materials by leveraging the folded conformation of TA groups and introducing intramolecular charge transfer (ICT) to enhance SOC. Benefiting from the separated fluorescence-RTP dual emission of these materials, highly sensitive ratiometric optical oxygen sensing can be achieved with a Stern-Volmer coefficient of up to 10.65 kPa–1. This study not only deepens the understanding of structure-property relationships in TA-based RTP materials but also provides an effective strategy for performance enhancement and functional development of purely organic RTP materials.