Iodates of trivalent manganese

Abstract

In 1924 a Swedish chemist F. Olssen reported the preparation of yellow and yellow-brown double iodates containing trivalent manganese and having the general formula M2Mn(IO3)5 where M = K,Rb,Cs,NH4. The problem initially set out for investigation, having made the potassium salt, was to find if, as the general formula suggests, the manganese has the unusual coordination number of five, or if the manganese is rendered six-coordinate by the attachment of one molecule of water of crystallisation. If the compound does in fact contain five-coordinate manganese, then it may possibly be an equimolecular mixture of K2MnII(IO3)4 and K2MnIV(IO3)6; this situation could be proved or disproved by measurement of the magnetic moment of the compound.