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Sodium cationization can disrupt the intramolecular hydrogen bond that mediates the sunscreen activity of oxybenzone
- Source :
- PCCP Physical Chemistry Chemical Physics, 22, 19522-19531, PCCP Physical Chemistry Chemical Physics, 22, 35, pp. 19522-19531, Phys. Chem. Chem. Phys.
- Publication Year :
- 2020
-
Abstract
- A key decay pathway by which organic sunscreen molecules dissipate harmful UV energy involves excited-state hydrogen atom transfer between proximal enol and keto functional groups. Structural modifications of this molecular architecture have the potential to block ultrafast decay processes, and hence promote direct excited-state molecular dissociation, profoundly affecting the efficiency of an organic sunscreen. Herein, we investigate the binding of alkali metal cations to a prototype organic sunscreen molecule, oxybenzone, using IR characterization. Mass-selective IR action spectroscopy was conducted at the free electron laser for infrared experiments, FELIX (600-1800 cm-1), on complexes of Na+, K+ and Rb+ bound to oxybenzone. The IR spectra reveal that K+ and Rb+ adopt binding positions away from the key OH intermolecular hydrogen bond, while the smaller Na+ cation binds directly between the keto and enol oxygens, thus breaking the intramolecular hydrogen bond. UV laser photodissociation spectroscopy was also performed on the series of complexes, with the Na+ complex displaying a distinctive electronic spectrum compared to those of K+ and Rb+, in line with the IR spectroscopy results. TD-DFT calculations reveal that the origin of the changes in the electronic spectra can be linked to rupture of the intramolecular bond in the sodium cationized complex. The implications of our results for the performance of sunscreens in mixtures and environments with high concentrations of metal cations are discussed.
- Subjects :
- Spectrophotometry, Infrared
Infrared Rays
Ultraviolet Rays
General Physics and Astronomy
Infrared spectroscopy
02 engineering and technology
010402 general chemistry
Photochemistry
01 natural sciences
Benzophenones
chemistry.chemical_compound
Isomerism
Coordination Complexes
Molecule
Physical and Theoretical Chemistry
Density Functional Theory
FELIX Molecular Structure and Dynamics
Hydrogen bond
Sodium
Photodissociation
Intermolecular force
Hydrogen Bonding
Rubidium
021001 nanoscience & nanotechnology
Enol
0104 chemical sciences
Models, Chemical
chemistry
13. Climate action
Intramolecular force
Potassium
Oxybenzone
0210 nano-technology
Sunscreening Agents
Subjects
Details
- Language :
- English
- ISBN :
- 978-1-952219-53-5
1-952219-53-1 - ISSN :
- 14639084 and 14639076
- ISBNs :
- 9781952219535 and 1952219531
- Database :
- OpenAIRE
- Journal :
- PCCP Physical Chemistry Chemical Physics, 22, 19522-19531, PCCP Physical Chemistry Chemical Physics, 22, 35, pp. 19522-19531, Phys. Chem. Chem. Phys.
- Accession number :
- edsair.doi.dedup.....7217980b9d992c361d887043e050627b