Investigation of Photoexcited States in Porcine Eumelanin through Their Transient Radical Products

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• 作者：Alice Wang ; Anthony R. Marino ; Elzbieta M. Gasyna ; Tadeusz Sarna ; James R. Norris ; Jr.
• 刊名：Journal of Physical Chemistry B
• 出版年：2009
• 出版时间：July 30, 2009
• 年：2009
• 卷：113
• 期：30
• 页码：10480-10482
• 全文大小：132K
• 年卷期：v.113,no.30(July 30, 2009)
• ISSN：1520-5207

文摘

Time-resolved electron paramagnetic resonance was used to monitor the photochemistry of radical pairs from melanin in porcine retinal pigment epithelial cells on the sub-microsecond time scale. Two distinct signals were found: one of enhanced absorption/emission at early times and one mostly emissive at later times. The emissive character of the longer lived feature suggests participation of an excited triplet precursor, something not generally thought to exist in melanins. The radicals in the early time signal were separated by about 21 Å and those in the later time signal were separated by about 22−24 Å.