The cyclization reaction of diarylethenes having an azulene ring occurs only via higher excitedstates. Novel diarylethenes having an azulene ring with a strong donor or acceptor were synthesized and examined in these reactions. A derivative having an electron‐donating 1,3‐benzodithiol‐2‐ylidenemethyl group at the 1‐position of the azulene ring showed photochromism, whereas neither a derivative having
ethene moiety were synthesized. One derivative having thiazole rings showed the expected coloration reaction by excitation at 313 nm (to a higher singlet state) but not when excited at 635 nm (S0 to S1 excitation). The system demonstrates that the cyclization reaction can be controlled by selective excitation at different wavelengths of the absorption spectrum. On the other hand, another derivative