Dedicated to Prof. Dr. Dr. h.c. Klaus Müllen on the occasion of his 75 th birthday Sterically highly crowded and twisted thienylene-phenylenes are synthesized and structurally characterized. Single-crystal X-ray structure analyses and theoretical studies give evidence of through-space delocalization of 𝝅-electrons of peripheral (hetero)aromatic rings in toroidal and catenated topology.

Diazocines are bridged azobenzenes with phenyl rings connected by a CH2-CH2 group. Despite this rather small structural difference, diazocine exhibits improved properties over azobenzene as a photoswitch and most importantly,...