Photochemistry of coronene with water at 10 K: first tentative identification by infrared spectroscopy of oxygen containing coronene products
Photochemistry of coronene with water at 10 K: first tentative identification by infrared spectroscopy of oxygen containing coronene products
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DOI：
10.1039/c0cp01756f
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发表时间：
2011-01-01
影响因子：
3.3
通讯作者：
Mascetti, Joelle
中科院分区：
文献类型：
--
作者：
Guennoun, Zohra;Aupetit, Christian;Mascetti, Joelle
研究了多环芳烃模型冠烯（C24H12）在低温氩气基质中与水相互作用、吸附在无定形水冰膜上以及嵌入固体水中时的紫外光化学反应。利用高压汞弧灯在10 K和λ > 235 nm下进行光处理，导致冠烯的氧化和还原。在同位素实验和DFT计算的支持下，通过FTIR光谱初步鉴定为1,10-二羟基coronene和1,10-coroquinone。这些光化学产物很可能在C24H12和H2O之间的氢键形成后，通过PAH的电离和随后在照射下与水的反应而形成。由此产生的阳离子随后与水反应，生成含氧的冠烯化合物。这些物种特别令人感兴趣，因为它们可能在星际和早期太阳系的冰中形成，而且由于它们在大多数生物体中发生的过程中发挥重要作用，也具有天体生物学意义。
UV photochemistry of a polycyclic aromatic hydrocarbon model, coronene (C24H12), has been investigated when it is in interaction with water in argon cryogenic matrices, adsorbed on amorphous water ice films, and embedded in solid water. Photoprocessing, carried out at 10 K and lambda > 235 nm by means of a high-pressure Hg arc lamp, results in the oxidation and reduction of coronene. These species have been tentatively identified as being the 1,10-dihydroxycoronene and the 1,10-coroquinone by FTIR spectroscopy with the support of isotopic experiments and DFT calculations. These photochemical products most likely form, after hydrogen bonding between C24H12 and H2O, through ionization of the PAH and subsequent reactivity with water upon irradiation. Cations, thus generated, react subsequently with water yielding the production of oxygen containing coronene compounds. Such species are of particular interest as they may form in interstellar and early Solar System ices, and are also of astrobiological significance as they could play an important role in processes taking place in most of the living organisms.