ChemInform Abstract: Neutron Powder Diffraction Study on Highly Deuterated Ca(IO3)2×D2O.

Neutron powder diffraction experiments were performed on highly deuterated calcium iodate monohydrate (bruggenite) to examine possible H/D enrichment effects. The title compound is built up of distorted CaO8 quadratic antiprisms. The iodate ions form layers parallel to (100), revealing relatively short interionic I ... O distances of 3.02 and 2.90 Angstrom. The water molecules are trigonally planar coordinated (2 IO3-, 1 Ca2+, site symmetry C-1), forming asymmetric hydrogen bonds of different strengths to adjacent iodate ions. Deviation from random distribution of the H atoms has been established.