Gao Han-Wen, Choi Hyun Wook, Hui Jie, Wang Lai-Sheng
Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States.
J Phys Chem A. 2024 May 9;128(18):3579-3586. doi: 10.1021/acs.jpca.4c01672. Epub 2024 Apr 25.
We report a high-resolution photoelectron imaging study of cryogenically cooled BiB and BiB clusters. Vibrational features are completely resolved for the ground-state detachment transitions, providing critical information about the structures of the anionic clusters and their corresponding neutrals. The electron affinities of BiB and BiB are accurately measured to be 2.174(1) and 2.121(1) eV, respectively. The B-B and Bi-B stretching frequencies are measured to be 1262 and 476 cm, respectively, in the ground state of BiB. Three vibrational frequencies are measured for the ground state of BiB: 1194 cm (B-B stretching), 782 cm (B-B stretching), and 339 cm (Bi-B stretching). Both BiB and BiB and their neutral ground states are found to have planar structures in which the Bi atom bridges two B atoms. BiB is found to have a triplet spin state (B), consistent with its complicated photoelectron spectra, whereas BiB is a doublet (B) and neutral BiB is closed shell (A). Both BiB and BiB consist of peripheral localized Bi-B and B-B σ bonds and delocalized π and σ bonds.
我们报告了对低温冷却的BiB和BiB团簇的高分辨率光电子成像研究。对于基态脱离跃迁，振动特征得到了完全分辨，为阴离子团簇及其相应中性体的结构提供了关键信息。BiB和BiB的电子亲和能经精确测量分别为2.174(1)和2.121(1) eV。在BiB的基态中，B - B和Bi - B的伸缩频率经测量分别为1262和476 cm。对BiB的基态测量了三个振动频率：1194 cm（B - B伸缩）、782 cm（B - B伸缩）和339 cm（Bi - B伸缩）。发现BiB和BiB及其中性基态均具有平面结构，其中Bi原子桥接两个B原子。发现BiB具有三重态自旋态（B），与其复杂的光电子能谱一致，而BiB是二重态（B），中性BiB是闭壳层（A）。BiB和BiB均由外围局域的Bi - B和B - B σ键以及离域的π键和σ键组成。
