Supramolecular trapping of a cationic all-metal σ-aromatic {Bi 4 } ring.

Autor: Yadav R; Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany.; School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, India., Maiti A; Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany., Schorpp M; Universität Regensburg, Regensburg, Germany., Graf J; Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany., Weigend F; Fachbereich Chemie, Philipps-Universität Marburg, Marburg, Germany. florian.weigend@chemie.uni-marburg.de., Greb L; Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany. greb@uni-heidelberg.de.
Jazyk: angličtina
Zdroj: Nature chemistry [Nat Chem] 2024 Sep; Vol. 16 (9), pp. 1523-1530. Date of Electronic Publication: 2024 May 17.
DOI: 10.1038/s41557-024-01530-z
Abstrakt: Aromaticity in organic molecules is well defined, but its role in metal-only rings remains controversial. Here we introduce a supramolecular stabilization approach of a cationic {Bi 4 } rhomboid within the symmetric charge sphere of two bowl-shaped dianionic calix[4]pyrrolato indinates. Crystallographic and spectroscopic characterization, quantum chemical analysis and magnetically induced ring currents indicate σ-aromaticity in the formally tetracationic 16-valence electron [Bi 4 ] 4+ ring. Computational screening for other p-block elements identifies the planar rhomboid as the globally preferred structure for 16-valence electron four-atomic clusters. The aromatic [Bi 4 ] 4+ is isoelectronic to the [Al 4 ] 4- , a motif previously observed as antiaromatic in Li 3 [Al 4 ] - in the gas phase. Thus, subtle factors such as charge isotropy seem to decide over aromaticity or antiaromaticity, advising for caution in debates based on the Hückel model-a concept valid for second-row elements but less deterministic for the heavier congeners.
(© 2024. The Author(s).)
Databáze: MEDLINE
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