BN Tetracene: Extending the Reach of BN/CC Isosterism in Acenes

The first synthesis of a tetracene BN isostere is reported. Comparison with its direct, all-carbon analogue reveals that the BN tetracene isostere exhibits a lower-lying HOMO and a slightly larger optical HOMO–LUMO gap. While all-carbon tetracenes are prone to photodecomposition, the BN tetracene scaffold is less light sensitive, owing in part to its much higher photoluminescence quantum yield. In the context of this larger BN tetracene family, we introduce simple guiding principles for predicting frontier orbital energies as a function of the position of the BN unit within the tetracene scaffold.