Aroylnitrenes with singlet ground states: photochemistry of acetyl-substituted aroyl and aryloxycarbonyl azides
作者:Michael E. Sigman、Tom. Autrey、Gary B. Schuster
DOI:10.1021/ja00221a032
日期:1988.6
light gives only the aroylnitrenes. The triplet excited states of the azides were detected chemically and by transient spectroscopic techniques. Nitrogen loss following near-UV irradiation occurs exclusively from the excited triplet azides. However, the chemical properties of ABN and ADN are consistent only with reactions originating from their singlet states. An ESR spectrum is observed at 8 K for
4-乙酰苯甲酰叠氮化物 (ABA)、4-乙酰-4'-联苯酰叠氮化物 (ADA) 和 4-乙酰苯氧羰基叠氮化物 (APA) 的光化学显示出不寻常的波长和结构效应。用深紫外光将 ABA 或 ADA 辐照到它们的 ..pi..-..pi..* 带中,分别导致 4-乙酰苯甲酰氮 (ABN) 和 4-乙酰-4'-联苯甲酰氮 (ADN) 的形成,与光库尔修斯重排竞争形成异氰酸酯。用近紫外光将这些叠氮化物照射到它们的 n-..pi..* 带中,仅产生芳酰基硝烯。叠氮化物的三重激发态通过化学方法和瞬态光谱技术进行检测。近紫外线照射后的氮损失仅发生在激发的三重叠氮化物上。然而,ABN 和 ADN 的化学性质仅与源自其单线态的反应一致。在 8 K 处观察到 ((4-乙酰苯氧基) 羰基) 氮烯 (APN) 的 ESR 谱,但 4-乙酰苯甲酰基氮 (ABN) 或 4-乙酰-4'-联苯羰基氮 (ADN) 没有。AP