Characterization of photophysical and photochemical properties of 2-ethyl-hexyl 4-methoxycinamate isomers. Influence of sunscreens on quenching of singlet molecular oxygen

PEGORARO, C.; CHIACCHIERA S.; MASSAD W.; PREVITALI, C.; CHESTA, C.; CHIAPPERO, M.; MONTEJANO, H.

Carlos Paz

Conferencia; 13th Latin American Conference on Physical Organic Chemistry (CLAFQO-13); 2015

The development and evaluation of sunscreens is important because UVA and UVB sunlight can penetrate deep into human skin and cause severe internal damage, besides erythema and photoaging. Although the photodegradation and the effect of the photoproducts of many molecules employed as sunscreens have been thoroughly studied, several aspects of the photophysical and photochemical behavior of these molecules are still not totally elucidated. Here we present a study of the photophysics and photochemistry of 2-ethylhexyl 4-methoxycinamate (EHMC) a molecule that has frequently present in commercial sunscreens. This UVB blocking is one of the most widely used in various fields of industry. There are over one hundred of industrial suppliers worldwide. Given the enormous annual consumption of EHMC, problems related to the accumulation of this compound in nature should be considered with great care. The main effect of UV irradiation of E-2-ethylhexyl 4-methoxycinamate (E) is trans/cis photoisomerization to form the Z isomer Z-2-ethylhexyl 4-methoxycinamate (Z).