Hydration and dynamics of a tetramethylammonium ion in water: a computer simulation study

Molecular dynamics experiments were performed to investigate the structure of one single tetramethylammonium (TMA) ion in water. The dynamical properties of the ion and its hydration shell molecules were examined. The TMA was analyzed as an ionic model in studying the hydrophobic behavior in water solutions. The orientation of the hydration shell molecules was nearly tangent to the ion. Lower self-diffusion coefficients were observed in the hydration shell molecules. However, TMA ions do not interfere with the low-frequency water power spectra.