Simultaneous expansion of 9,10 boron-doped anthracene in longitudinal and lateral directions.

Doubly boron-doped anthracenes and pentacenes have been longitudinally and laterally expanded through annulation of thiophene or benzene rings. The obtained series of closely related compounds allowed an assessment of key structure-property relationships with a focus on optoelectronic characteristics. Most of the products are benchtop-stable blue emitters and capable of accepting two electrons in a reversible manner. The syntheses involved late-stage modifications through photocyclization or stepwise oxidative C-C coupling (DDQ/BF3·Et2O) as well as cyclocondensation of ortho-disilylated or -diborylated aryl building blocks.