The Crystal Structure of Potassium Hydrogeniodate (V), KIO3•HIO3

Abstract

The crystal structure of KIO3•HIO3 has been determined by three-dimensional single crystal X-ray diffraction and by neutron powder diffraction. The crystallographic data are a = 7.025(2), b = 8.206(2), c = 21.839(5) Å, β = 97.98(2)°, space group P21/c, Z = 8 units KIO3•HIO3. The residual [Formula: see text] was 0.048 for 7516 independent X-ray reflections measured on a three-circle diffractometer with Zr-filtered Mo radiation. The results of the present study show good qualitative agreement with the structure recently determined by Chan and Einstein (7). The HIO3 and [Formula: see text] groups are pyramidal, the I—O(H) bonds vary from 1.898 to 1.939(4) Å and the I—O bonds from 1.786 to 1.827(4) Å, these lengths are not corrected for the effects of thermal motion. Strong O—I … O interactions and electrostatic attractions between K+ and Oδ− give slabs of thickness [Formula: see text] The slabs are connected by hydrogen bonds of 2.710 and 2.694 Å.