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

The crystal structure of KIO3•HIO3has 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 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 HIO3and 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 The slabs are connected by hydrogen bonds of 2.710 and 2.694 Å.