Abstract Skin cancer is a serious public health problem
worldwide, being incident over all five continents and affecting
an increasing number of people. As sunscreens are considered
an important preventive measure, studies to develop
better and safer sunscreens are crucial. Cinnamates are UVB
filters with good efficiency and cost-benefit, therefore, their
study could lead to the development of new UV filters. A
benchmark to define the most suitable density functional theory
(DFT) functional to predict UV–vis spectra for ethylhexyl
methoxycinnamate was performed. Time-dependent DFT
(TD-DFT) calculations were then carried out [B3LYP/6-
311+G(d,p) and B3P86/6-311+G(d,p) in methanol environment]
for seven cinammete derivatives implemented in the
Gaussian 03 package. All DFT/TD-DFT simulations were
performed after a conformational search with the Monte-
Carlo method and MMFF94 force field. B3LYP and B3P86
functionals were better at reproducing closely the experimental
spectra of ethylhexyl methoxycinnamate. Calculations of
seven cinnamates showed a λmax of around 310 nm, corroborating
literature reports. It was observed that the energy for the
main electronic transition was around 3.95 eV and could be
explained by electron delocalization on the aromatic ring and
ester group, which is important to UVabsorption. The methodology
employed proved to be suitable for determination of
the UV spectra of cinnamates and could be used as a tool for
the development of novel UV filters.