Spin-orbit effects on magnetically induced current densities in the M5- (M = N,P,As,Sb,Bi,Mc) clusters

Area of Science:

• Quantum Chemistry
• Computational Chemistry
• Relativistic Effects

Background:

• Aromaticity is a key concept in chemistry, influencing molecular stability and reactivity.
• Relativistic effects, particularly spin-orbit coupling, become significant for heavy elements.
• Understanding these effects is crucial for accurately predicting molecular properties.

Purpose of the Study:

• To investigate the influence of spin-orbit coupling on the aromaticity of N5-, P5-, As5-, Sb5-, Bi5-, and Mc5- anionic clusters.
• To quantify the impact of relativistic effects on magnetic aromaticity indices.
• To compare spin-orbit effects across different periods of the periodic table.

Main Methods:

• Utilizing all-electron density functional theory (DFT) calculations.
• Employing the four-component Dirac-Coulomb (DC) Hamiltonian to include scalar and spin-orbit relativistic effects.
• Calculating the magnetic index of aromaticity via numerical integration of current density.

Main Results:

• Spin-orbit coupling was found to significantly influence the aromaticity of heavy anionic clusters, specifically Bi5- and Mc5-.
• A comparison between spin-orbit coupled and spin-free calculations revealed notable differences in aromaticity indices.
• The study provides quantitative data on the magnitude of spin-orbit effects on aromaticity for these systems.

Conclusions:

• Spin-orbit coupling is a critical factor in determining the aromaticity of heavy pnictogen and post-pnictogen anionic clusters.
• Relativistic calculations are essential for accurate predictions of aromaticity in systems containing heavy elements.
• This work advances the understanding of electronic structure and bonding in heavy element chemistry.