Jaffe Noah B, Stanton John F, Heaven Michael C
Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States.
Department of Chemistry - Quantum Theory Project, University of Florida, Gainesville, Florida 32611, United States.
J Phys Chem Lett. 2023 Sep 21;14(37):8339-8344. doi: 10.1021/acs.jpclett.3c02169. Epub 2023 Sep 12.
Computational studies of small beryllium clusters (Be) predict dramatic, nonmonotonic changes in the bonding mechanisms and per-atom cohesion energies with increasing . To date, experimental tests of these quantum chemistry models are lacking for all but the Be molecule. In the present study, we report spectroscopic data for Be and Be obtained via anion photodetachment spectroscopy. The trimer is predicted to have symmetric equilibrium structures for both the neutral molecule and the anion. Photodetachment spectra reveal transitions that originate from the XA″ ground state and the 1A' electronically excited state. The state symmetries were assigned on the basis of anisotropic photoelectron angular distributions. The neutral and anionic forms of Be are predicted to be tetrahedral. Franck-Condon diagonal photodetachment was observed with a photoelectron angular distribution consistent with the expected BeXA → BeXA transition. The electron affinities of Be and Be were determined to be 11363 ± 60 and 13052 ± 50 cm, respectively.
对小铍团簇（Be）的计算研究预测，随着团簇尺寸增大，其键合机制和单原子凝聚能会发生显著的非单调变化。到目前为止，除了Be分子外，这些量子化学模型都缺乏实验验证。在本研究中，我们报告了通过负离子光剥离光谱法获得的Be和Be的光谱数据。预测三聚体的中性分子和负离子都具有对称平衡结构。光剥离光谱揭示了源于XA″基态和1A'电子激发态的跃迁。根据各向异性光电子角分布确定了态对称性。预测Be的中性和负离子形式为四面体结构。观察到了与预期的BeXA→BeXA跃迁一致的光电子角分布的弗兰克-康登对角光剥离。确定Be和Be的电子亲和能分别为11363±60和13052±50cm⁻¹。
