Magnetic Characterization of the Infinitene Molecule

Area of Science:

• Theoretical Chemistry
• Aromaticity Studies
• Computational Chemistry

Background:

• Infinitene, a 24-carbon molecule with an infinity symbol shape, presents unique electronic properties.
• Understanding induced currents in polycyclic aromatic hydrocarbons is crucial for predicting their behavior.
• Previous work by Orozco-Ic et al. suggested global current pathways in infinitene.

Purpose of the Study:

• To calculate the origin-independent current density in infinitene induced by a perpendicular magnetic field.
• To confirm and analyze the previously reported global current pathways.
• To investigate the relationship between molecular structure, aromaticity, and induced currents.

Main Methods:

• Computational calculation of current density using a perpendicular magnetic field.
• Analysis of current strength along carbon-carbon bonds within the infinitene structure.
• Comparison of calculated currents with experimental data, specifically high-field 1H NMR signals.

Main Results:

• Confirmed two disjointed global current pathways along the edges of the infinitene molecule.
• The molecule exhibits a diamagnetic exaltation of 73% of the expected value for aromatic systems.
• Observed through-space currents, 10% the strength of benzene's ring current, along electron density gradient paths.
• High-field 1H NMR signals correlate with the two counter-rotating global currents in specific molecular regions.

Conclusions:

• The study validates the existence and nature of global current pathways in infinitene.
• Infinitene's unique shape leads to reduced diamagnetic exaltation compared to typical aromatic molecules.
• Experimental NMR data provides evidence for the calculated electronic current distribution and behavior.