Copper indium sulfide quantum dots enabling quantitative visible light photoisomerisation of ( E )-azobenzene chromophores.

Azobenzene derivatives have long been studied for their photochromic behaviour. One of the greatest challenges in this field is the quantitative ( E ) to ( Z ) photoconversion triggered by visible light irradiation. In this work, the synthesis and characterization of CuInS 2 quantum dots (CIS-QDs) appended with azobenzene units are reported: quantitative ( E ) → ( Z ) isomerisation is obtained by visible light ( e.g. , λ ex = 533 nm). Interestingly, catalytic amounts of CIS-QDs allow the full photoconversion of ungrafted ( E )-azobenzene derivatives into the corresponding ( Z )-isomers using visible light. This peculiar behaviour is associated with the direct complexation of the ( Z )-isomer on the QD surface.