Journal of Physical Chemistry A, Vol.106, No.44, 10505-10509, 2002
Structure, dynamics, and magnetic shieldings of permanganate ion in aqueous solution. A density functional study
Car-Parrinello molecular dynamics simulations have been performed for MnO4- in the-gas phase and in aqueous solution. Dynamic averaging at ca. 300 K affords only minor changes for the mean Mn-O bond length with respect to the optimized value r(e) = 1.622 Angstrom (BP86 value). Magnetic shieldings, evaluated at the GIAO-B3LYP level for snapshots along the trajectories, decrease upon going from the equilibrium values to the dynamic averages in water. For Mn-55 and O-17, the resulting sigma(300K) - sigma(e) values amount to -36 and +31 ppm, respectively. The structure of the solvation shell around permanganate ion in water is characterized by the mean number of hydrogen-bonded solvent molecules (approximately 4) and by the g(MnO) pair correlation function.