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This content will become publicly available on November 25, 2026

Title: Emergence of bulk-like structural features and 2D-to-3D transition in boron nanoclusters
As an electron-deficient element, boron possesses fascinating three-dimensional structures and unconventional chemical bonds. Nanoclusters of boron have also been found to exhibit intriguing structural properties, observed to have predominantly planar structures, in stark contrast to bulk boron allotropes, which are composed of the ubiquitous B12icosahedral building blocks. Here, we report observation of the 2D-to-3D transition and bulk-like structural features in the size-selected boron clusters, as revealed by photoelectron spectroscopy, chemisorption experiments, and first-principles calculations. In the small to medium cluster size range, planar boron cluster anions are found to be unreactive and only B46–and B56–are observed to chemisorb C2H4and CO under ambient conditions, suggesting major structural transitions at these cluster sizes. Notably, B56–is also found to be able to chemisorb and activate CO2. The global minimum of B46–is found to adopt a core-shell structure (B2@B44–), consisting of a B2core within a B44shell, reminiscent of the interstitial B2dumbbells in the high-pressureγ-B28form of bulk boron. More remarkably, both the global minimum and the second most stable isomer of B56–exhibit nest-like configurations, featuring the iconic B12icosahedral core surrounded by a B44half-shell (B12@h-B44–), signifying the onset of bulk-like structural characteristics in boron nanoclusters.  more » « less
Award ID(s):
2403841
PAR ID:
10657931
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publisher / Repository:
NAS
Date Published:
Journal Name:
Proceedings of the National Academy of Sciences
Volume:
122
Issue:
47
ISSN:
0027-8424
Page Range / eLocation ID:
e2510702122
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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