Photophysical Properties of Sulfone-Based TADF Emitters In Relation To Their Structural Properties

In this work, Thermally Activated Delayed Fluorescence (TADF) of a series of emitters with sulfone-based acceptor moieties were studied by Density Functional Theory (DFT) methods. Sulfone derivatives were shown to be high performing TADF emitters over recent years. When discussing the TADF efficiency, various properties, such as, singlet–triplet energy gap (∆EST), spin–orbit coupling (SOC), nature of states and the hyperfine coupling (HF) stand out due to their roles in reverse intersystem crossing (RISC). Here, we mainly focused on three important structural parameters that affect the intersystem crossing (ISC) and RISC pathways and their efficiencies. These three parameters are: 1) effect of meta- and para- conjugation, 2) effect of rigid acceptor moieties and 3) effect of phenyl bridge on photophysical properties.