Observation of an electron-precise metal boryne complex: [Bi&z.tbd;BH]

• Published in: Chemical communications (Cambridge, England) Vol. 59; no. 83; pp. 12431 - 12434
• Main Authors: Gao, Han-Wen, Hui, Jie, Wang, Lai-Sheng
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 17.10.2023
• Subjects: Anions; Boron; Chemical bonds; Chemical reactions; Couplings; Electronic structure; Photoelectrons
• ISSN: 1359-7345; 1364-548X
• DOI: 10.1039/d3cc04235a

Metal-boron triple bonds are rare due to the electron deficiency of boron. This study uncovers a simple electron-precise metal boryne complex, [Bi&z.tbd;BH] − , which is produced within an ion trap through chemical reactions of the open-shell BiB − anion with H 2 . Photoelectron imaging is used to investigate the electronic structure and chemical bonding of the BiBH − complex. The B atom in the linear closed-shell BiBH − is found to undergo sp hybridization, forming a B-H single bond and a Bi&z.tbd;B triple bond. Photoelectron imaging reveals three detachment transitions from the BiBH − ( 1 Σ + ) anion to the neutral BiBH, including the ground state ( 2 Π 3/2 ) and two excited states ( 2 Σ + and 2 Π 1/2 ). Strong vibronic coupling is observed between the 2 Π 3/2 and 2 Σ + states, evidenced by the appearance of bending vibrations and their unique photoelectron angular distributions. The BiBH − complex not only stands as the simplest metal boryne complex, but also serves as an ideal molecular system to investigate both spin-orbit and vibronic couplings. Metal-boron triple bonds are rare due to the electron deficiency of boron.