Facile synthesis of azobenzene‐embedded conjugated macrocycles for optically switchable single‐crystal transistors and tunable supramolecular assemblies

A series of new π ‐conjugated macrocycles ( AzoM‐n‐ E , n = 1–3) incorporating azobenzene units have been synthesized by a facile strategy in one‐pot reaction. The resultant azobenzene‐embedded macrocycles feature intrinsic photoresponsive behaviors and intriguing supramolecular assembling properties. The smallest macrocycle AzoM‐1‐ E with a rigid planar conjugated backbone structure is used to prepare the single crystal transistors, showing reversible optical tunability. The moderate size macrocycle AzoM‐2‐ E assembles into a dimer in the form of interpenetration through π‐π stacking between azobenzene units. The largest macrocycle AzoM‐3‐ E with enhanced flexibility can adaptively assemble with various types of electron‐deficient guests accompanied by distortion of azobenzene. Typically, AzoM‐3‐ E assembles with the planar F4‐TCNQ to form a tetragonal geometry by C‐F···π and π‐π interactions, while the assembly with ellipsoidal C 70 via π‐π interactions induces AzoM‐3‐ E to form a boat‐shaped geometry. This work will shed new light on the development of functional conjugated macrocycles in organic electronics.