The role of symmetric functionalisation on photoisomerisation of a UV commercial chemical filter Electronic supplementary information (ESI) available: H-1 and C-13 NMR spectra, crystallographic data, computed structures, additional transient absorption, and steady-state spectra, fitting residuals, fluorescence quantum yields and power dependency measurements. See DOI:; 10.1039/c8cp06536e

摘要

Photoisomerisation has been shown to be an efficient excited-state relaxation mechanism for a variety of nature-based and artificial-based molecular systems. Here we report on the excited-state relaxation dynamics and consequent photostability of a symmetrically functionalised cinnamate by transient electronic absorption spectroscopy, along with complementary computational and steady-state spectroscopy methods. The findings are then discussed in comparison to 2-ethylhexyl-E-4-methoxycinnamate, a structurally related 'off the shelf' chemical filter present in commercial sunscreens with a similar absorption profile. The present study allows for a like-for-like comparison beween 2-ethylhexyl-E-4-methoxycinnamate and the functionalised cinnamate, driven by the need to enhance solar protection across both the UVA and UVB regions of the electromagnetic spectrum.