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Author Xie, Wen Jun ♦ Yang, Yi Isaac ♦ Gao, Yi Qin
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY ♦ ANIONS ♦ ATOMS ♦ CHEMICAL BONDS ♦ HALIDES ♦ HYDRATION ♦ HYDROGEN ♦ MOLECULAR IONS ♦ MOLECULES ♦ NITRATES ♦ OXYGEN ♦ RELAXATION ♦ ROTATION ♦ SOLUTES ♦ WATER
Abstract In this study, we examine how complex ions such as oxyanions influence the dynamic properties of water and whether differences exist between simple halide anions and oxyanions. Nitrate anion is taken as an example to investigate the hydration properties of oxyanions. Reorientation relaxation of its hydration water can occur through two different routes: water can either break its hydrogen bond with the nitrate to form one with another water or switch between two oxygen atoms of the same nitrate. The latter molecular mechanism increases the residence time of oxyanion’s hydration water and thus nitrate anion slows down the translational motion of neighbouring water. But it is also a “structure breaker” in that it accelerates the reorientation relaxation of hydration water. Such a result illustrates that differences do exist between the hydration of oxyanions and simple halide anions as a result of different molecular geometries. Furthermore, the rotation of the nitrate solute is coupled with the hydrogen bond rearrangement of its hydration water. The nitrate anion can either tilt along the axis perpendicularly to the plane or rotate in the plane. We find that the two reorientation relaxation routes of the hydration water lead to different relaxation dynamics in each of the two above movements of the nitrate solute. The current study suggests that molecular geometry could play an important role in solute hydration and dynamics.
ISSN 00219606
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-12-14
Publisher Place United States
Journal Journal of Chemical Physics
Volume Number 143
Issue Number 22


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