respectively. The IR and UV/Vis spectra are compared with p-xylylene and the benzyl radical as models for a quinoid or diradicaloid structure. The absence of an ESR signal reveals a singlet ground state for these compounds. Remarkable is a sharp absorption in the red part of the visible spectrum which is not observed in the case of p-xylylene or the benzyl radical. The electronic structure can be
在
氩气中于10 K分离的[2.2]对环环烯(3)和苯并[2.2]对环环烯(4)的紫外线光解导致
乙醇桥的裂解和化合物5和8的形成, 分别。的IR和UV / Vis光谱与比较p -xylylene和苄基作为模型醌型或diradicaloid结构。没有ESR信号揭示了这些化合物的单重态基态。显着的是在可见光谱的红色部分有明显的吸收,这在对亚二
甲苯基或苄基的情况下没有观察到。可以将电子结构描述为具有大量双自由基特征的
喹诺酮。