Investigation of the changes in hydrogen bonding accompanying the structural reorganization at 103K in Ammonium iodate

Jones

Abstract

Neutron powder diffraction has been used to observe the changes in hydrogen bonding that occur
as a function of temperature in ND4IO3, and thus determine the structural features that occur during
the low temperature (103 K) phase transition. We show that in the deuterated material the change
is not a phase change per se but rather a structural reorganization in which the hydrogen bonding
becomes “firmly locked in” at the phase transition temperature, and stays in this configuration upon
further cooling to 4.2 K. In addition, both the differences and changes in the axial thermal
expansion coefficients in the region 100 – 290K can be explained by the changes involving both the
hydrogen bonding and secondary I---O halogen bonds.

Citation

Jones. (2019). Investigation of the changes in hydrogen bonding accompanying the structural reorganization at 103K in Ammonium iodate. Acta crystallographica. Section B, Structural science, https://doi.org/10.1107/s2052520619000325

• Acceptance Date: Jan 8, 2019
• Publication Date: Apr 1, 2019
• Journal: Acta Crystallographica Section B: Structural Science
• Print ISSN: 0108-7681
• Publisher: International Union of Crystallography
• DOI: https://doi.org/10.1107/s2052520619000325
• Keywords: neutron diffraction; hydrogen bonding; phase transitions; variable temperature; ammonium ion.
• Publisher URL: https://doi.org/10.1107/s2052520619000325