In this study, we conducted precise measurements to determine the bond dissociation energy of F₂, yielding a value of 12939.95 ± 0.40 cm^–1 or 154.7962 ± 0.0048 kJ/mol. Our research addresses this currently debated benchmark parameter crucial in thermochemistry and quantum chemistry. By analyzing a rotationally resolved spectrum of an ion-pair state close to the threshold of F(²P_3/2^°) + F(²P_3/2) in the energy region of 14.6 eV, we made a significant observation. We discovered two neighboring rotational states with and without predissociation to the channel, exhibiting an energy spacing of 1.4 cm^–1 only. This enabled us to determine the bond dissociation energy of F₂ with an uncertainty of 0.7 cm^–1, which was further reduced to 0.4 cm^–1 using threshold fragment yield spectra of F(²P_3/2). Consequently, the accuracy of the F₂ bond dissociation energy now surpasses 0.5 cm^–1, placing it with similar precision to those of N₂, O₂, and CO.

中文翻译：

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使用预解离和阈值片段产率光谱法测量的 F2 键解离能和光谱精度


在这项研究中，我们进行了精确测量以确定 F₂ 的键解离能，得到的值为 12939.95 ± 0.40 cm^–1 或 154.7962 ± 0.0048 kJ/mol。我们的研究解决了这个目前争论不休的基准参数，这些参数在热化学和量子化学中至关重要。通过分析在 14.6 eV 能量区域中接近 F（²P_3/2^°） + F（²P_3/2） 阈值的离子对态的旋转分辨光谱，我们做出了重要的观察。我们发现了两个相邻的旋转状态，有和没有对通道的预解离，能量间距仅为 1.4 cm^–1。这使我们能够确定 F₂ 的键解离能，不确定性为 0.7 cm^–1，使用 F（²P_3/2） 的阈值碎屑产率光谱进一步降低到 0.4 cm^–1。因此，F₂ 键解离能的精度现在超过 0.5 cm^–1，使其精度与 N₂、O₂ 和 CO 相似。