Journal of Physical Chemistry B, Vol.119, No.10, 4053-4060, 2015
Water Wires in Aqueous Solutions from First-Principles Calculations
We elucidate the concept of water wires in aqueous solutions in view of their structural and dynamical properties by means of first-principiles molecular dynamics simulations. We employ a specific set of hydroxyquinoline derivatives (heteroarornatic fluorescent dyes) as probe in molecules that provide a well-defined initial and final coordinate for possible water wires by meats of their photoacid and photobase functionalities. Besides the geometric structure of the hydrogen bond network connecting these functional sites, we focus on the dependence of the length of the resulting Water Wire on the initial/final coordinates determined by the chromophore. Special attention is devoted to the persistence of the wires on the picosecond time stale and their capability of shifting the nature of the proton transfer process from a concerted to a stepwise mechanism. Our results shed light on the long debate on whether water wires represent characteristic.structural motifs or transient phenomena.