Fig. 1: Phenoxyl and azobenzene building blocks of CAR and the bicycle pedal motion.
From: Normal & reversed spin mobility in a diradical by electron-vibration coupling
Phenoxyl (a) and azobenzene (b) building blocks of CAR with the bicycle pedal motion in azobenzene and in oligoenes. c Extreme quinoidal/aromatic canonical forms of CAR (note the differences between these extreme forms and the quinoidal-like, aromatic-like, and pseudoquinoidal forms discussed below that always correspond to hybrids with sizeable weights of the two extreme forms).
