Fluoride crystal structures. Part XVII. Dipotassium pentafluoro-manganate(III) hydrate

Abstract

Crystals of dipotassium pentafluoromanganate(III) hydrate are monoclinic, space group P2₁/m, a= 6·04, b= 8·20, c= 5·94 Å, β= 96·5°, Z= 2. The structure was refined by three-dimensional least squares methods to R 0·093 for 663 reflections. In the crystal the water molecule is not co-ordinated to manganese, and the manganese atoms are linked through trans bridging fluorine atoms to give endless kinked chains parallel to b, with a distorted octahedral co-ordination of the manganese atoms. Mn–F distances are 1·82, 1·84, and 2·07 Å. The potassium ions and water molecule, together with the fluorine atoms, are arranged in a distorted cubic close packed arrangement, where the distortion can be correlated with a hydrogen bonding network.