Regulation of the frontier molecular orbitals and photophysical properties of boron tropolonate complexes by regioselective functionalization

Here, we show that the C5 substitution in α-tropolone efficiently modulates the energy level of the highest occupied molecular orbital rather than the lowest unoccupied one. Furthermore, the C5-substitution imparts functional luminescent properties, such as aggregation-induced emission, room-temperature phosphorescence, and thermally activated delayed luminescence.