Dispersion interactions between neighboring Bi atoms in (BiH₃ )₂ and Te(BiR₂ )₂

Area of Science:

• Inorganic Chemistry
• Computational Chemistry
• Materials Science

Background:

• Observed short Bi⋯Bi distances and specific bond angles in bis(diethylbismuthanyl)tellurane crystal structures.
• Need for theoretical investigation into interactions between neighboring bismuth (Bi) atoms in related molecules.

Purpose of the Study:

• To computationally investigate the nature and strength of Bi⋯Bi interactions in Te(BiR2)2 and (BiH3)2 systems.
• To determine the influence of heavy atom d-shell inclusion on Bi⋯Bi distances.
• To analyze the anisotropy of interactions and conformational preferences.

Main Methods:

• Quantum chemical computations, including spin component-scaled second-order Møller-Plesset theory (SCS-MP2) and coupled-cluster singles and doubles theory including perturbative triples (CCSD(T)).
• Density functional theory-based symmetry-adapted perturbation theory (DFT-SAPT) for analyzing interaction anisotropy.
• Geometry optimization and relative stability calculations for various conformers.

Main Results:

• Bi⋯Bi distances significantly shorten when the d shells of heavy metal atoms are included in electron correlation treatment.
• SCS-MP2 interaction energies show good agreement with CCSD(T) results.
• DFT-SAPT analysis revealed the interplay of dispersion attraction and steric repulsion between Bi atoms.
• Geometries, relative stabilities, and interconversion barriers for syn-syn and syn-anti conformers of Te(BiR2)2 were computed.

Conclusions:

• The study confirms the importance of including d-shell electrons in computational treatments for accurate prediction of short Bi⋯Bi distances.
• Advanced computational methods provide reliable data for understanding bonding and conformational behavior in bismuth-containing compounds.