A theoretical study of the UV absorption of 4-methylbenzylidene camphor: from the UVB to the UVA region

In this study, a theoretical approach was used to study the UV absorption of the UVB filter, 4- methylbenzylidene camphor. The main objective of this work was to design new UVA filters based on this rather photo- stable compound, so that photo- degradation in this UV region can be avoided without the use of other molecules. This objective was achieved by the simultaneous addition of two appropriate substituents, which led to red- shifts of up to 0.69 eV while maintaining appreciable oscillator strength. Also, useful structure- energy relationships were derived, which allow for the development of more UVA filters based on 4- methylbenzylidene camphor.