Photolysis of Indan-1,2-dione Derivatives in Oxygen-Doped Argon Matrix at Low Temperature
作者:Takayoshi Itoh、Jiro Tatsugi、Hideo Tomioka
DOI:10.1246/bcsj.82.475
日期:2009.3.15
Photolysis of indan-1,2,3-trion (1a), benzo[b]furan-2,3-dione (1b), and N-methylisatin (1c) in argon matrix either with or without oxygen at 10 K was investigated by IR spectroscopy in combination with DFT calculations. The results indicate that while 1a and 1b gave the products mixture as a result of α-cleavage, followed by decarbonylation, 1c was rather photostable under similar conditions. However, when the irradiation was carried out in argon matrix doped with 20% oxygen, 1c decomposed much more efficiently than that in argon matrix and cyclic diacyl peroxide presumably formed by trapping of initial diradical originating from α-cleavage by molecular oxygen was detected. Similar irradiation of 1b also gave cyclic diacyl peroxide along with photodecarbonylation products, but irradiation of 1a in oxygen-doped matrix produced not only cyclic diacyl peroxide but also products as a result of oxidation of photodecarbonylation product. The present observation reveals that photolysis of ketones in oxygen-doped matrix at low temperature provides useful information concerning the reactivities of ketones toward α-cleavage.
在10 K下,使用红外光谱结合DFT计算,研究了在氩气矩阵中有无氧气存在下,茚-1,2,3-三酮(1a)、苯并[b]呋喃-2,3-二酮(1b)和N-甲基靛红(1c)的光解作用。结果表明,1a和1b由于α-裂解随后脱羰基化生成产物混合物,而1c在相似条件下表现出较高的光稳定性。然而,当在掺有20%氧气的氩气矩阵中进行辐照时,1c的分解效率远高于在纯氩气矩阵中,并且检测到可能通过初始二自由基与分子氧结合形成的环状二酰基过氧化物。类似地,1b的辐照也生成了环状二酰基过氧化物和光脱羰基化产物,但在掺氧矩阵中辐照1a不仅生成了环状二酰基过氧化物,还生成了光脱羰基化产物的氧化产物。目前的观察揭示了在低温下掺氧矩阵中酮的光解作用提供了关于酮α-裂解反应性的有用信息。