Halogen-bonding interactions with π systems: CCSD(T), MP2, and DFT calculations

Area of Science:

• Computational chemistry
• Supramolecular chemistry
• Chemical physics

Background:

• Halogen bonding is a crucial noncovalent interaction.
• Interactions involving aromatic π systems are prevalent but understudied.
• Understanding these interactions is vital for various chemical and biological systems.

Purpose of the Study:

• To investigate halogen bonding interactions with aromatic π systems.
• To determine binding energies for interactions between NCX/PhX and benzene.
• To evaluate the performance of computational methods for these interactions.

Main Methods:

• Coupled cluster with perturbative triple excitations [CCSD(T)] extrapolated to the complete basis set limit.
• Møller-Plesset perturbation theory to second order (MP2).
• Density functional theory (DFT) using common functionals.

Main Results:

• Binding energies for halogen bonding with benzene were calculated.
• CCSD(T) results provide a benchmark for comparison.
• DFT methods show good agreement with CCSD(T) for these interactions.

Conclusions:

• Halogen bonding with aromatic π systems is significant.
• DFT calculations are reliable for studying these interactions.
• DFT's efficiency makes it valuable for exploring similar systems.