Azobenzenes are archetypal molecules that have a central role in fundamental and applied
research. They are widely used in the chemical industry as food additives, acid-base indicators,
radical reaction initiators, and therapeutic agents. Photochemical reversible isomerization
between the trans and the cis isomers of azobenzenes upon exposure to UV, visible light or
thermal conditions is well-known. However, its reactivity under visible light conditions has been
scarce investigated. We have studied the photoreactivity of alkynyl azobenzenes showing that
different structures can be afforded simply varying the reaction conditions.