Magnetically Induced Current-Density Susceptibility of Circum[n]coronenes.

Area of Science:

• Computational Chemistry
• Materials Science
• Organic Chemistry

Background:

• Coronoid molecules exhibit unique electronic properties.
• Understanding magnetically induced current density (MICD) is crucial for characterizing aromaticity.
• Previous models may not fully capture complex current distributions in large molecules.

Purpose of the Study:

• To calculate MICD susceptibility for coronoid molecules of increasing size.
• To compare all-electron density functional theory (DFT) results with the pseudo-π (PP) model.
• To investigate the behavior of magnetically induced ring currents (MIRCs) and Clar's aromatic sectors.

Main Methods:

• All-electron density functional theory (DFT) calculations.
• Calculation of MICD susceptibility.
• Application of the pseudo-π (PP) model for comparison.

Main Results:

• Coronoid molecules sustain global diatropic MIRCs and localized paratropic MICD vortices within benzene rings.
• The PP model accurately predicts alternating MICD patterns in circum[n]coronene molecules.
• Global diatropic MIRC increases with molecular size, indicating no upper limit for circum[n]coronene molecules.
• Odd 'n' circum[n]coronene molecules show internal Clar rings, while even 'n' and outer regions lack them.

Conclusions:

• The PP model is a computationally efficient tool for predicting MICD patterns in large coronoid systems.
• The observed MIRC behavior suggests potential for novel electronic applications in extended polycyclic aromatic hydrocarbons.
• The absence of outer Clar rings in larger molecules impacts their overall aromatic character and reactivity.