Transition-metal-centered monocyclic boron wheel clusters (M©Bnq) represent a family of interesting borometallic compounds with double aromaticity. A variety of early and late transition metal atoms have been found to form such structures with high symmetries and various Bn ring sizes. Here we report a combined photoelectron spectroscopy and quantum chemistry theoretical study of two M©Bn– clusters from the middle of the transition metal series: Re©B8– and Re©B9–. Global minimum structure searches reveal that ReB8– adopts a pseudo-C8v structure, while ReB9– is a perfect-planar D9h molecular wheel. Chemical bonding analyses show that both clusters exhibit and double aromaticity and obey the electronic design principle for metal-centered borometallic molecular wheels. The central Re atom are found to possess unusually low oxidation states of +I in Re©B8– and +II in Re©B9–, i.e. the Re atom behaves similarly to late transition-metal elements (Ru, Fe, Co, Rh, Ir) in the M©Bn– molecular wheels. These two clusters become new members of the family of transition-metal-centered monocyclic borometallic molecular wheels, which may be viable for chemical syntheses with appropriate ligands.
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This content will become publicly available on October 1, 2024
The Structures and Bonding of Bismuth-Doped Boron Clusters: BiB4− and BiB5−
We present an investigation on the structures and chemical bonding of two Bi-doped boron clusters BiBn− (n = 4, 5) using photoelectron spectroscopy and theoretical calculations. The electron affinities of BiB4 and BiB5 are measured to be 2.22(2) eV and 2.61(2) eV, respectively. Well-resolved photoelectron spectra are obtained and used to compare with theoretical calculations to verify the structures of BiB4− and BiB5−. Both clusters adopt planar structures with the Bi atom bonded to the periphery of the planar Bn moiety. Chemical bonding analyses reveal that the Bn moiety maintains σ and π double-aromaticity. The Bi atom is found to induce relatively small structural changes to the Bn moiety, very different from transition metal-doped boron clusters.
more » « less- Award ID(s):
- 2053541
- NSF-PAR ID:
- 10499247
- Publisher / Repository:
- MDPI
- Date Published:
- Journal Name:
- Inorganics
- Volume:
- 11
- Issue:
- 10
- ISSN:
- 2304-6740
- Page Range / eLocation ID:
- 405
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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