Spectroscopic Properties of Naphthalene on the Surface of Ice Grains Revisited: A Combined Experimental鈥揅omputational Approach

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• 作者：J谩n Krausko ; Joseph K鈥橢kuboni Malongwe ; Gabriela Bi膷anov谩 ; Petr Kl谩n ; Dana Nachtigallov谩 ; Dominik Heger
• 刊名：Journal of Physical Chemistry A
• 出版年：2015
• 出版时间：August 13, 2015
• 年：2015
• 卷：119
• 期：32
• 页码：8565-8578
• 全文大小：690K
• ISSN：1520-5215

文摘

An experimental-computational method is used to investigate the spectroscopic behavior of naphthalene on the surface of ice grains. UV鈥搗is diffuse reflectance and fluorescence spectroscopies of naphthalene combined with DFT and ADC(2) calculations provide evidence for the occurrence of excited-state associates. The measured and calculated bathochromic shifts of the S₀ 鈫?S₁ electronic transitions related to naphthalene dimers or naphthalene鈥搃ce interactions do not exceed 3 nm. The bands observed in the emission spectrum of frozen naphthalene solutions are assigned to excited dimers of different mutual orientations, naphthalene phosphorescence, and fluorescence of anthracene present as a trace impurity and populated by the energy transfer from excited naphthalene. Photochemical reactivity in/on ice and snow is dependent on the absorption properties and speciation of the compounds present in these media. Hence, within this study, we exploit frozen solutions of naphthalene to demonstrate both the absence of considerable bathochromic shift and a strong tendency to aggregate.