Redox Potentials for Tetraplatin, Satraplatin, Its Derivatives, and Ascorbic Acid: A Computational Study

Area of Science:

• Computational Chemistry
• Inorganic Chemistry
• Medicinal Chemistry

Background:

• Platinum(IV) complexes are investigated as potential anticancer agents.
• Accurate redox potential calculations are vital for understanding their biological activity and stability.
• Computational methods offer a way to predict these properties.

Purpose of the Study:

• To determine the redox potentials of platinum(IV) complexes using various Density Functional Theory (DFT) functionals.
• To assess the impact of ligand substitution (hydration) and solvent pH on redox potentials.
• To correlate computational predictions with experimental data and explore biological relevance.

Main Methods:

• Density Functional Theory (DFT) calculations with multiple functionals (B3LYP, ω-B97XD, PBE1PBE, TPSSTPSS, M06-L, M11-L, MN12-L).
• Comparison with post-Hartree-Fock methods (MP2, CCSD(T)).
• Implicit solvation model (IEF-PCM) for water solution and analysis of electron density distribution.

Main Results:

• DFT methods show good agreement with experimental redox potentials (RMSD ~0.23 V).
• Hydration of chloro ligands and solvent pH significantly influence redox potentials.
• A correlation was found between axial ligand binding energies and redox potentials.

Conclusions:

• DFT provides a reliable tool for predicting redox potentials of Pt(IV) complexes.
• Understanding redox properties is key for designing effective platinum-based anticancer drugs.
• Ascorbic acid's reduction potential was calculated for potential biological interactions.