Fingerprints of antiaromaticity in the negative ion (Li$_3$Al$_4$)$^-$ via an ab initio quantum-chemical study of the equilibrium structure of the inhomogeneous electron liquid

TL;DR

This study uses ab initio quantum-chemical methods to investigate the structure and electronic properties of the negative ion (Li$_3$Al$_4$)$^-$, revealing antiaromaticity signatures through chemical shifts and electronic characteristics.

Contribution

It provides the first predicted equilibrium geometry and electronic features of (Li$_3$Al$_4$)$^-$, highlighting antiaromaticity indicators via NICS calculations.

Findings

No sensitivity of HOMO to Al$_4$ geometry changes

Chemical shifts reveal antiaromaticity

Equilibrium structure predicted for the ion

Abstract

Fingerprints of antiaromaticity in the negative ion (Li$_3$Al$_4$)$^-$, this species being realizable via a laser vaporization technique, are revealed by means of an \emph{ab initio} quantum-chemical investigation. First, the ground-state equilibrium geometry of this ion is predicted. Also, for the corresponding inhomogeneous electron liquid, the characteristics of the HOMO are studied, both for the square and the rectangular Al$_4$ geometry in two low-lying isomers of the negative ion. There is no particular sensitivity to the change in geometry of the Al$_4$ configuration. Therefore, we have calculated theoretically chemical shifts (NICS), which contain remarkable fingerprints of antiaromaticity. As to future directions, some comments are added in relation to the Shannon entropy.