Magnetically Induced Current Density in Nonplanar Fully Benzenoid Hydrocarbons

Area of Science:

• Computational Chemistry
• Organic Chemistry
• Quantum Chemistry

Background:

• Previous work established Clar formulas' utility for local aromaticity in nonplanar benzenoid hydrocarbons.
• Understanding molecular planarity's role in electronic properties is crucial for predicting chemical behavior.

Purpose of the Study:

• To investigate the influence of molecular planarity on ab initio magnetically induced current densities in benzenoid hydrocarbons.
• To rationalize planarity effects by analyzing the origins of induced current density.

Main Methods:

• Calculations of ab initio magnetically induced current densities for series of increasingly planar benzenoid hydrocarbons.
• Analysis of virtual transitions between occupied and unoccupied molecular orbitals to understand current density origins.

Main Results:

• Molecular planarity significantly influences magnetically induced current densities.
• The distribution of local aromaticity, even in nonplanar systems, is accurately described by Clar formulas.
• Induced current densities can be rationalized by examining electronic transitions.

Conclusions:

• Molecular planarity is a key factor affecting magnetic response in benzenoid systems.
• Clar aromaticity concepts remain valid for assessing local aromaticity in nonplanar molecules.
• The study provides insights into the relationship between molecular geometry and electronic aromaticity.