Photolysis of regioisomeric diazides of 1,2-diphenylacetylenes studied by matrix-isolation spectroscopy and DFT calculations
作者:Hideo Tomioka、Shinji Sawai
DOI:10.1039/b308138a
日期:——
position of azide groups in the diphenylacetylene unit. Whenever two azide groups were situated in a conjugating position with respect to each other, as in p,p'-, o,o'-, and p,o'-bis(azides), the azides always resulted in the formation of a quinoidal diimine diradical in which unpaired electrons were extensively delocalizedin the pi-conjugation. The situation changed rather dramatically when azide groups
一系列1,2-二苯基乙炔的重氮化物在低温下在基质中光解,并通过IR,UV / vis方法与ESR研究相结合来表征瞬态光产物。理论计算还用于了解实验结果。在苯基叠氮化物上引入苯基乙炔基对光化学途径的影响很小。因此,在光激发下,(苯基乙炔基)苯基叠氮化物提供了相应的三重态氮,其与相应的氮杂环庚七烯处于光平衡中。与之形成鲜明对比的是,叠氮基苯基乙炔基不仅对叠氮化物的光化学途径表现出显着的影响,而且对光产物的电子和分子结构也表现出显着的影响。作用方式取决于二苯基乙炔单元中叠氮化物基团的相对位置。每当两个叠氮化物基团相对于彼此处于共轭位置时,例如在p,p'-,o,o'-和p,o'-bis(叠氮化物)中,叠氮化物总是导致形成a quinoidal diimine diradical,其中不成对的电子在π共轭中广泛离域。当将叠氮化物基团引入间位时,情况发生了相当大的变化。因此,在m.m′-异构体的光解中