质子化
光化学
二苯甲酮
化学
碎片(计算)
质谱法
分子
离解(化学)
光解
离子
物理化学
有机化学
色谱法
计算机科学
操作系统
作者
Cate S. Anstöter,Natalie G. K. Wong,Kgato P. Selwe,Caroline E. H. Dessent
标识
DOI:10.1002/cptc.202300133
摘要
Abstract Octocrylene (OCR) is a widely used organic sunscreen molecules, and is a dominant component of many sunscreen formulations. Here, we perform the first measurements on the protonated form of OCR, i. e . [OCR+H] + , to probe whether protonation affects the molecule's photostability. The novel photochemical technique of UV laser‐interfaced mass spectrometry is employed from 400–216 nm, revealing that the electronic absorption spectrum of OCR across the S 1 and S 2 states red shift by 40 nm upon protonation. Our measurements reveal that [OCR+H] + predominantly undergoes photofragmentation into the m/z 250 and 232 ionic products, associated with loss of its bulky alkyl side chain, and subsequent loss of water, respectively. We compare the photochemical fragmentation results with higher‐energy collisional dissociation results to investigate the nature of the photodynamics that occur following UV absorption. The excited state decay pathways over the S 1 and S 2 excited states of [OCR+H] + are associated with statistical fragmentation in line with dominant ultrafast decay. This behaviour mirrors that of neutral OCR, demonstrating that protonation does not affect the ultrafast decay pathways of this sunscreen molecule. We discuss our results in the context of the known breakdown of OCR into benzophenone, identifying a potential photoactivated pathway to benzophenone formation in solution.
科研通智能强力驱动
Strongly Powered by AbleSci AI