Structure, Bonding and Stability of Boron Substituted Tungsten Clusters

TL;DR

This study uses density functional theory to analyze how boron substitution affects the structure and electronic stability of small tungsten clusters, revealing increased stability and altered bonding characteristics.

Contribution

It provides new insights into the structural and electronic effects of boron substitution in tungsten clusters, highlighting stability enhancements and bonding changes.

Findings

Boron substitution causes geometric distortions and symmetry reduction.

Increased binding energy and HOMO-LUMO gap with boron incorporation.

Enhanced electronic stability and reduced reactivity in W-B clusters.

Abstract

In this study, we investigate effects of boron substitution on the structural and electronic properties of small tungsten clusters using density functional theory (DFT). We construct a series of tungsten boride clusters by replacing tungsten atoms with boron atoms to analyze their stability and other properties. Boron substitution in Wn clusters results in significant geometric distortions shortening the bond lengths and thereby reducing the clusters overall symmetry. The boron atoms prefers to occupy apex or edge positions. Its lower atomic radius and stronger electronegativity are the driving forces behind these structural changes.The binding energy per atom, HOMO LUMO gap, and chemical hardness increase with boron incorporation, indicating enhanced electronic stability.Additionally, negative chemical potentials are observed, which confirm greater charge localization and lower reactivity.BB stretches at high frequencies suggest strong boron-boron bonds with localized electrons, consistent with negative chemical potentials that promote charge retention over delocalization. WB modes in mid frequencies reflect metal boron interactions stabilizing the cluster, reducing overall reactivity as seen in prior Fukui analyses of electron density.Fukui functions pinpoint nucleophilic or electrophilic sites on W-B clusters, corroborating low reactivity from localized charges negative potentials confirm electrons are tightly bound, limiting site accessibility for reactions.