Boron-, carbon-, and silicon-bridged 1,12-dihydroxy-perylene bisimides with tuned structural and optical properties

Additional data to report https://doi.org/10.1039/D3QO01389H

Establishing suitable design strategies to tailor the functional properties of perylene bisimide (PBI) dyes are critical for their successful application in various devices. Herein, we report a new synthetic strategy to tune their structural and fluorescence properties by employing 1,12-bay-substitution pattern that has been seldomly investigated in the past. Central to the strategy is the use of 1,12-dihydroxy-PBI as a starting compound and the subsequent bridging of these hydroxy bay-functional groups with either a boron, carbon or silicon atom resulting in derivatives with rigidified perylene core. This is followed by a detailed exploration of synthetic possibilities to functionalize the unsubstituted 6,7-positions at the opposite bay area to achieve novel perylene dyes with excellent structural and optical properties. The fluorescence color could be tuned from green to dark-orange while retaining the almost unity fluorescence quantum yield in solution. Moreover, a strong fluorescence with quantum yields as high as 40% has been observed for powders, which clearly illustrates the potential of the presented structural design to obtain new solid-state emitters.