oxybenzone

It is used as an ingredient in sunscreen and other cosmetics because it absorbs UVB and short-wave UVA ( [|ultraviolet] ) rays. Oxybenzone was one of the first compounds incorporated into sunscreen formulations to offer enhanced UVA protection because its absorption spectrum extends to less than 350 nm. Oxybenzone's ability to absorb UV rays is due to a variety of molecular interactions. In this compound, both of the phenyl rings can interact with the C=O group through induct
 * Oxybenzone** ( [|trade names] **Eusolex 4360**, **Escalol 567**) is an [|organic compound] used in [|sunscreens] . It forms colorless crystals that are readily soluble in most organic solvents.

The source of these oxybenzone concerns is a Washington DC non-profit: Environmental Working Group (EWG). Chief Scientist, Dr. John Bailey with the Personal Care Products Council, a group representing the interests of the cosmetics industry, says the following about the EWG findings: "EWG’s report lacks scientific credibility", "EWG’s allegations are in direct conflict with the established scientific and FDA safety assessments of sunscreen products and their ingredients, including those from scientific and regulatory bodies in the European Union, Canada, and several other countries", "EWG invents its own sunscreen product rating system based on very questionable scientific methodology... proven to be inaccurate and unreliable by sunscreen experts around the world". ive effects and mesomeric effects. The overlapping of the π bonds of both phenyl rings and that of the C=O creates a completely conjugated molecule as evidenced by the MO diagram. This causes the C=O group to lose part of its individual character as it integrates with the two phenyl rings. This stabilizes the system due to the transference of electron deficiency from the carbon of the carbonyl towards three of the carbons of the phenyl rings. When examining the stability of the oxybenzone, which contributes to the absorption capabilities of the molecule, studies show that the molecule is basically locked into the conformation that places the OH group close to the C=O. Because the oxygen contains most of the electron density of the C=O bond, the electrons can interact with the hydrogen of the OH group. As a result, oxybenzone is more stable by 35.6 kJ/mol due to the presence of the intramolecular hydrogen bonding capabilities. The hydrogen bond can be classified as a "moderate" or "conventional-strong" bond, which has electrostatic character. It is this conformation that leads to oxybenzone's absorption capabilities. Research studies show that at room temperature, oxybenzone does not undergo benzophenone-like photoreduction and does not phosphoresce. At low temperatures, however, it is possible to observe both the phosphoresce and the triplet-triplet absorption spectrum. At 175K the triplet lifetime is only 24 ns. The short lifetime has been attributed to an extremely fast and reversible excited-state intramolecular hydrogen transfer between the oxygen of the C=O and the OH. This pathway provides an efficient energy-wasting pathway that is responsible for the absorption capabilities.