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The Synthesis of [Sn10SiSiMe334]2- Using a Metastable SnI Halide Solution Synthesized via a Co-condensation Technique
Published on: November 28, 2016
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Electronic Structure of All-Metal Neutral M4 (M = Al, Ga, In) Rings: Aromaticity and Spin-Avoided σ-σ Diradical
Amit Das1, Palash J Thakuria1, Ankur K Guha1
1Advanced Computational Chemistry Centre, Department of Chemistry, Cotton University, Guwahati, Assam 781001, India.
The Journal of Physical Chemistry. A
|May 5, 2026
Summary
Neutral aluminum, gallium, and indium rings exhibit unique aromatic properties. The bare aluminum-4 ring displays rare sigma-sigma diradical character, unlike other metal rings.
Area of Science:
- Inorganic chemistry
- Theoretical chemistry
- Quantum chemistry
Background:
- Aromaticity is a fundamental concept in organic chemistry, governing the stability and reactivity of cyclic conjugated systems.
- While all-metal aromaticity in anionic clusters (e.g., Al4(2-)) is known, neutral metal rings (M4, M = B-In) remain less explored.
Purpose of the Study:
- To investigate the electronic structure and aromaticity of neutral M4 (M = B-In) rings.
- To characterize the diradical nature of these neutral metal clusters.
Main Methods:
- Computational chemistry methods were employed to study the electronic properties.
- Density Functional Theory (DFT) calculations were performed.
Main Results:
- The neutral bare Al4 ring exhibits a rare sigma-sigma diradical character.
- Other neutral M4 rings (M = Ga, In) display mixed sigma-pi diradical character.
- Neutral Al4 rings are double (sigma + pi) aromatic, analogous to Al4(2-).
- Neutral Ga4 and In4 rings are sigma-aromatic.
Conclusions:
- Neutral M4 rings possess distinct aromaticity and diradical characteristics compared to their anionic counterparts.
- The findings expand the understanding of all-metal aromaticity beyond charged systems.
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