Using DFT-based molecular dynamics simulations incorporating explicit water solvent, we elucidate the varying behavior of the ligand pKa of a molecular catalyst for methanol dehydrogenation, using the Ru(PNP) catalytic system as a case study. The pKa of the amido ligand moiety in this catalytic system is highly sensitive to the species adsorbed on the metal center, resulting in a substantial variation in the ligand pKa along the catalytic cycle. Since the ligand pKa is an important characteristic that determines the exact role of the ligand during aqueous methanol dehydrogenation, it has important implications for metal-ligand cooperative pathways.
- Ligand pKa
- Aqueous methanol dehydrogenation
- Explicit solvent
- Ab-initio molecular dynamics