Is iodate a strongly hydrated cation?

Research output: Contribution to journalArticle


We show, through a combination of density function theory-based molecular dynamics simulations (DFT-MD) and experimental X-ray absorption fine structure spectroscopy (XAFS) studies, that the iodate ion (IO 3 -) contains a local region that is strongly hydrated as a cation. The local region adjoining the I atom is sufficiently electropositive that three hydrating waters are oriented with their O atoms directly interacting with the iodine atom at an I-O H2O distance of 2.94 Å. This is the orientation of water hydrating a cation. Further, approximately 2-3 water molecules hydrate each O of IO 3 - through their H atoms in an orientation of the water that is expected for an anion at an I-O H2O distance of 3.83 Å. We predict that this structure persists, although to a much lesser degree, for BrO 3 -, and ClO 3 -. This type of local microstructure profoundly affects the behavior of the "anion" at interfaces and how it interacts with other ionic species in solution.


  • Marcel D. Baer
  • Van-Thai Pham
  • John L. Fulton
  • Gregory K. Schenter
  • Mahalingam Balasubramanian
  • Christopher J. Mundy
External organisations
  • Pacific Northwest National Laboratory
  • Argonne National Laboratory
Original languageEnglish
Pages (from-to)2650-2654
Number of pages5
JournalJournal of Physical Chemistry Letters
Issue number20
Publication statusPublished - 2011 Oct 20
Publication categoryResearch
Externally publishedYes