Protocols for Understanding the Redox Behavior of Copper-Containing Systems.

Area of Science:

• Computational Chemistry
• Inorganic Chemistry

Background:

• Copper macrocycle complexes are vital in various chemical processes.
• Accurate prediction of their redox potentials is crucial for understanding reactivity.
• Density Functional Theory (DFT) is a common computational tool, but its suitability for these systems requires validation.

Purpose of the Study:

• To assess the suitability of single-reference DFT methods for calculating redox potentials of copper macrocycles.
• To determine optimal computational parameters, including basis sets and solvation models.
• To propose a reliable computational scheme for these systems.

Main Methods:

• Utilized single-reference DFT methods with T1 diagnostics to check for spin contamination and wave function instability.
• Investigated the convergence of redox potentials with increasing cc-pVnZ basis set size.
• Evaluated the performance of the Def2-TZVPP all-electron basis set in conjunction with cc-pVTZ geometries.
• Employed the M06 functional with the polarizable continuum model (PCM) for solvation.

Main Results:

• Single-reference DFT methods were confirmed as suitable for copper macrocycle redox potential calculations.
• Results converged at the cc-pVTZ basis set level.
• The Def2-TZVPP basis set with cc-pVTZ geometry proved effective.
• The M06/PCM model chemistry demonstrated the best performance.

Conclusions:

• A reliable computational scheme for copper macrocycle redox potentials is proposed using M06/cc-pVTZ with PCM solvation.
• This approach accurately reproduces experimental trends.
• The study validates DFT as a powerful tool for studying these important complexes.