Sequence-independent activation of photocycloadditions using two colours of light
Philipp W Kamm1,2,3, Leona L Rodrigues1,2, Sarah L Walden1,2
1Centre for Materials Science, Queensland University of Technology (QUT) 2 George Street Brisbane QLD 4000 Australia j.blinco@qut.edu.au christopher.barnerkowollik@qut.edu.au.
Abstract:
We exploit two reactive chromophores to establish sequence-independent photochemical activation, employing ortho-methyl benzaldehyde (oMBA) and N,N-(dimethylamino)pyrene aryl tetrazole (APAT) with N-(2-hydroxy)ethyl maleimide (NHEM), without any additives. Critically, the order of the irradiation sequence is irrelevant, as the shorter wavelength does not activate the higher wavelength activated species. Therefore, full sequence-independent λ-orthogonality is achieved through differences in both the reaction quantum yields (Φ r, and Φ r,APAT) and wavelength-dependent reactivity profiles of the employed chromophores.
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