Methyl salicylate, a vegetable substance traditionally used as a sunscreen, it may be used in the design of modern technological applications, thanks to its particular reaction to light. This is indicated by a recent survey of the Autonomous University of Madrid, Spain, which managed to get a model that opens the door to the development of these applications.
In a recent paper published in Physical Chemistry Chemical Physics, Javier Catalan, a researcher at the Autonomous University of Madrid (UAM), proposes a comprehensive framework that links the existing scientific evidence on “the unique photophysical behavior of methyl salicylate.”
Methyl salicylate is a substance-photostable solar radiation does not affect their chemical composition by the double-proton transfer that regenerates its molecular structure. However, the compound is still more interesting photophysical behavior for scientists is the ability to generate two fluorescent emissions from a single excited electronic state.
The fluorescence is a particular type of light emission characteristic of substances which are capable of absorbing energy as electromagnetic radiation, and then emit the same manner but with a different wavelength. Generally, fluorescent substances absorb energy in the form of short wave electromagnetic radiation (X-rays and UV radiation, for example), and emit at a longer wavelength.
The dual fluorescence shown by methyl salicylate was studied for the first time by a German scientist, A. Weller, in 1956. Since then, scientists around the world have struggled to fully understand its nature, an emerging consensus that the two fluorescence of the compound are generated by the presence of two conformers, which have in its structure an intramolecular hydrogen bond.
More precisely, the work of Javier Catalan determines that only the most stable conformer of methyl salicylate has a first fluorescence that is structured, low intensity and begins to be detected at approximately 337 nanometers wavelength. And second, it is much more intense, focused around the 450 nanometers, and that structure develops.
“The viability of potential technological innovations derived from methyl salicylate passes properly understand these features,” says the researcher. His latest work not only provides a model for better understanding of these, but also provides important guidelines for the design of organic substances that could be used to store memory at the molecular level.
Methyl salicylate is a substance that can be extracted from birch branches or tea and traditionally has been given various medicinal and domestic uses, such as sunscreen. It is in fact, in ancient Egyptian women already applied in their skins, thus protecting from UV radiation from sunlight.
Currently, the methyl salicylate is produced synthetically by mixing salicylic acid and methanol, and the study of their photophysical behavior is opening a range of technological applications ranging from the use of its molecular structure for generating laser radiation, to designing substances capable of storing information at the molecular level (using the dual fluorescence phenomenon).