Simultaneously enhancing the planarity and electron-donating capability of donors for through-space charge transfer TADF towards deep-red emission.

Through-space charge transfer (TSCT) has been proven effective for designing thermally activated delayed fluorescence (TADF) emitters due to the separation of the frontier molecular orbitals. Although tuning of the interaction between the donor and acceptor by controlling the conformation is known to be crucial for the photophysical properties of TSCT excited states, it remains a challenge to realize efficient red and deep-red emissions. Herein, we designed two TSCT molecules, namely TPXZ-QX and TPXZ-2QX, by using oxygen-bridged triphenylamine (TPXZ) as the electron donor with enhanced planarity and electron-donating capability.