Fruitful interplay between theory and experiment in the design of circularly polarized luminescent materials

Preliminary computations of NBN-benzo[f,g]tetracene/BINOL tethered structures (R)-/(S)-1 and (R)-/(S)-2 that suggest high oscillator strengths f and dissymmetry factors for CPL glum incited us to synthesize these compounds. The optical transitions within these structures have strong charge-transfer character from the benzotetracene-localized HOMOs to the LUMOs located at the BINOL. Large Stokes shifts of around 3500 cm-1 are observed alongside quantum yields of 53-64%. The absorption and luminescence dissymmetry factors from ECD and CPL spectra were measured as gabs = +/- 0.7 x 10-3 (1) and +/- 1.0 x 10-3 (2), and glum = +/- 0.5-0.6 x 10-3 (1) and +/- 1.6 x 10-3 (2), resulting in a CPL brightness (BCPL) of 12.7-15.1 M-1 cm-1. This work shows that computational screening of chiroptical properties prior to synthesis is useful for identification of suitable materials.A computational approach identified BINOL-derived emitters for circularly polarized luminescence (CPL). Very good agreement between computed and experimental glum factors was observed when state-specific solvation was included.