Gao Han-Wen, Hui Jie, Wang Lai-Sheng
Department of Chemistry, Brown University Providence RI 02912 USA
Chem Sci. 2025 Mar 17;16(16):7004-7009. doi: 10.1039/d5sc00812c. eCollection 2025 Apr 16.
Due to its electron deficiency, boron triple bonds are relatively scarce. We use high-resolution photoelectron imaging to investigate the structures and bonding of the EBO (E = P, As) type of clusters, which are found to have [E[triple bond, length as m-dash]B-B[triple bond, length as m-dash]O] closed-shell linear structures with E[triple bond, length as m-dash]B triple bonds. The B atoms in the linear EBO species undergo sp hybridization, while the E atoms also undergo sp hybridization to form a σ bond with the sp orbital of B along with two π bonds formed by the p and p orbitals. The high-resolution photoelectron imaging data reveal detachment transitions from the EBO (Σ) anions to the EBO (Π) neutrals. The electron affinities of PBO and AsBO are measured to be 3.592(1) eV and 3.432(1) eV, respectively; the vibrational frequencies for the E-B, B-B, and B-O stretching modes are measured for both species. The spin-orbit splitting of the Π state to Π and Π is measured to be 153 cm and 758 cm for PBO and AsBO, respectively.
由于硼三键存在电子缺乏问题，所以相对较少见。我们利用高分辨率光电子成像技术研究了EBO（E = P、As）型团簇的结构和键合情况，发现它们具有[E≡B - B≡O]闭壳层线性结构，其中含有E≡B三键。线性EBO物种中的B原子进行sp杂化，而E原子也进行sp杂化，以与B的sp轨道形成一个σ键，同时由p和p轨道形成两个π键。高分辨率光电子成像数据揭示了从EBO（Σ）阴离子到EBO（Π）中性分子的脱离跃迁。测得PBO和AsBO的电子亲和能分别为3.592(1) eV和3.432(1) eV；同时测量了这两种物种的E - B、B - B和B - O伸缩模式的振动频率。对于PBO和AsBO，Π态到Π和Π的自旋轨道分裂分别测得为153 cm和758 cm。
