Structural and dynamical properties of Co(III) in aqueous solution: Ab initio quantum mechanical/molecular mechanical molecular dynamics simulation

摘要

A combined ab initio quantum mechanical/molecular mechanical (QM/MM) molecular dynamics simulation has been performed to evaluate the structural and dynamical properties of Co(III) in water. The average Co(III)-O distance resulting from the simulation is 1.67 A for the first hydration shell, and the coordination numbers are 6-15 for first/second hydration shell. Ligand exchanges between the second hydration shell and the bulk occur with a mean ligand residence time of approx55 ps, estimate from there events observed during the simulation. The hydration enthalpy of -11744+-8 kcal/mol, determined by the QM/MM molecular dynamics simulation, is in good agreement with experimental estimations.