Molecular Simulation Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran 16846-13114, Iran.
Phys Chem Chem Phys. 2018 Oct 31;20(42):27069-27081. doi: 10.1039/c8cp05422c.
Classical molecular dynamics simulations of the hydration thermodynamics, structure, and dynamics of water in hydration shells of charged buckminsterfullerenes are presented in this study. Charging of fullerenes leads to a structural transition in the hydration shell, accompanied by creation of a significant population of dangling O-H bonds pointing toward the solute. In contrast to the well accepted structure-function paradigm, this interfacial structural transition causes nearly no effect on either the dynamics of hydration water or on the solvation thermodynamics. Linear response to the solute charge is maintained despite significant structural changes in the hydration shell, and solvation thermodynamic potentials are nearly insensitive to the altering structure. Only solvation heat capacities, which are higher thermodynamic derivatives of the solvation free energy, indicate some sensitivity to the local hydration structure. We have separated the solvation thermodynamic potentials into direct solute-solvent interactions and restructuring of the hydration shell and analyzed the relative contributions of electrostatic and nonpolar interactions to the solvation thermodynamics.
本研究采用经典分子动力学模拟方法，研究了带电荷富勒烯水合壳层中水分子的水合热力学、结构和动力学。富勒烯的带电会导致水合壳层的结构转变，同时会产生大量指向溶质的悬空 O-H 键。与广为接受的结构-功能范例相反，这种界面结构转变对水合水的动力学或溶剂化热力学几乎没有影响。尽管水合壳层发生了显著的结构变化，但对溶质电荷的线性响应仍然保持，并且溶剂化热力学势对结构的变化几乎不敏感。只有溶剂化热容，它是溶剂化自由能的较高热力学导数，表明对局部水合结构有一定的敏感性。我们将溶剂化热力学势分解为直接的溶质-溶剂相互作用和水合壳层的重构，并分析了静电和非极性相互作用对溶剂化热力学的相对贡献。
