A high temperature phenyl-mediated addition–cyclization–dehydrogenation mechanism to form peri-fused polycyclic aromatic hydrocarbon (PAH) derivatives—illustrated through the formation of dibenzo[e,l]pyrene (C₂₄H₁₄)—is explored through a gas-phase reaction of the phenyl radical (C₆H₅˙) with triphenylene (C₁₈H₁₂) utilizing photoelectron photoion coincidence spectroscopy (PEPICO) combined with electronic structure calculations. Low-lying vibrational modes of dibenzo[e,l]pyrene exhibit out-of-plane bending and are easily populated in high temperature environments such as combustion flames and circumstellar envelopes of carbon stars, thus stressing dibenzo[e,l]pyrene as a strong target for far-IR astronomical surveys.

中文翻译：

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通过苯基自由基介导的成环气相制备二苯并[e,l]芘 (C24H14) 蝶形分子

通过气体-探索了高温苯基介导的加成-环化-脱氢机制，以形成全稠合多环芳烃（PAH）衍生物——通过二苯并[ e,l ]芘（C ₂₄ H ₁₄）的形成来说明。利用光电子光电离子符合光谱 (PEPICO) 结合电子结构计算，苯基 (C ₆ H ₅ ˙) 与苯并菲 (C ₁₈ H _{12 )}发生相反应。二苯并[ e,l ]芘的低位振动模式表现出面外弯曲，并且很容易在高温环境中填充，例如燃烧火焰和碳星的星周包层，因此强调二苯并[ e,l ]芘作为远红外天文调查的有力目标。