Colour change of chemiluminescence for base‐induced decomposition of dioxetane bearing a 4‐(4‐cyanophenyl)iminomethyl‐3‐hydroxyphenyl group

A bicyclic dioxetane 1 bearing a 4‐(4‐cyanophenyl)iminomethyl‐3‐hydroxyphenyl group was found to undergo base‐induced decomposition with the accompanying emission of light, the colour of which changed depending on the base used and its concentration. When 1 was triggered with tetrabutylammonium fluoride (TBAF), 1 displayed an emission of glowing orange light. On the other hand, on treatment with a high concentration of potassium t‐butoxide complexed with 18‐crown‐6 ether, 1 afforded a flash of blue light. The mechanistic study of this unprecedented phenomenon revealed that the emission of glowing orange light was due to the normal oxido anion of keto ester 11, whereas the emission of a flash of blue light was attributed to another species that was produced by addition of a nucleophile to an iminomethyl of unstable oxido anion of dioxetane 10. Copyright © 2008 John Wiley & Sons, Ltd.