Structure and Dynamics of Metal Ions in Solution:  QM/MM Molecular Dynamics Simulations of Mn2+ and V2

• Published in: Journal of the American Chemical Society Vol. 125; no. 6; pp. 1618 - 1624
• Main Authors: Schwenk, Christian F., Loeffler, Hannes H., Rode, Bernd M.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 12.02.2003
• Subjects: Chemistry; Exact sciences and technology; General and physical chemistry; Solutions; Solvation. Solvent properties; Autocorrelation function; Vibrational interaction; Monte Carlo method; Molecular dynamics method; Theoretical study; Manganese ion; Vanadium ion; Transition metal Ions; Solution structure; Molecular mobility; Radial distribution function; Molecular reorientation; Ab initio calculations; Aqueous solution
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja0286831

Structural and dynamical properties of the transition metal ions V2+ and Mn2+ in aqueous solution, resulting from combined quantum mechanical (QM)/molecular mechanical (MM) molecular dynamics (MD) simulations have been compared. The necessity of polarization functions on the ligand's oxygen for a satisfactory description of such ions in aqueous solution is shown using V2+ as test case. Radial distribution functions, coordination number distributions, and several angle distributions were pursued for a detailed structural comparison of the first hydration shells. Dynamical properties, such as the librational and vibrational motions of water molecules were evaluated by means of velocity autocorrelation functions. Approximative normal coordinate analyses were employed to calculate the rotational frequencies and vibrational motions around the three principal axes. The very low exchange rates for the first shell water exchanges only allow an investigation of the water exchange processes in the second shell, which take place within the picosecond range.