(Aza)Pentacenes Clipped into a Ring: Stabilization of Large (Aza)Acenes

A doubly alkylene bridged 6,13-diphenylpentacene and analogously bridged azapentacenes were prepared; they are persistent. The doubly bridged azapentacenes display superior photochemical, oxidative and thermal stabilities compared to azapentacenes protected by bis(TIPS-ethynyl)-substituents - clipping an azaacene into a large ring is a viable complement in stabilization.