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Abstract Multiple bonds between boron and transition metals are known in many borylene (:BR) complexes via metal dπ→BR back‐donation, despite the electron deficiency of boron. An electron‐precise metal–boron triple bond was first observed in BiB2O−[Bi≡B−B≡O]−in which both boron atoms can be viewed as sp‐hybridized and the [B−BO]−fragment is isoelectronic to a carbyne (CR). To search for the first electron‐precise transition‐metal‐boron triple‐bond species, we have produced IrB2O−and ReB2O−and investigated them by photoelectron spectroscopy and quantum‐chemical calculations. The results allow to elucidate the structures and bonding in the two clusters. We find IrB2O−has a closed‐shell bent structure (Cs,1A′) with BO−coordinated to an Ir≡B unit, (−OB)Ir≡B, whereas ReB2O−is linear (C∞v,3Σ−) with an electron‐precise Re≡B triple bond, [Re≡B−B≡O]−. The results suggest the intriguing possibility of synthesizing compounds with electron‐precise M≡B triple bonds analogous to classical carbyne systems.
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This content will become publicly available on November 1, 2025
On the remarkable resistance to oxidation by the Bi 18 − cluster
The reactivity of Bin−clusters (n= 2 to 30) with O2is found to display even-odd alternations. The open-shell even-sized Bin−clusters are more reactive than the closed-shell odd-sized clusters, except Bi18−, which exhibits no observable reactivity toward O2. We have investigated the structure and bonding of Bi18−to understand its remarkable resistance to oxidation. We find that the most stable structure of Bi18−consists of two Bi8cages linked by a Bi2dimer, where each atom is bonded to three neighboring atoms. Chemical bonding analyses reveal that each Bi uses its three 6pelectrons to form three covalent bonds with its neighbors, resulting in a Bi18−cluster without any dangling bonds. We find that the robust Bi18framework along with the totally delocalized unpaired electron is responsible for the surprising inertness of Bi18−toward O2. The Bi18framework is similar to that in Hittorf’s phosphorus, suggesting the possibility to create bismuth nanoclusters with interesting structures and properties.
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- Award ID(s):
- 2403841
- PAR ID:
- 10565883
- Publisher / Repository:
- AAAS
- Date Published:
- Journal Name:
- Science Advances
- Volume:
- 10
- Issue:
- 44
- ISSN:
- 2375-2548
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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