Solvothermal Synthesis and Structure of Anhydrous Manganese( II ) Formate, and Its Topotactic Dehydration from Manganese( II ) Formate Dihydrate

Recrystallization of manganese(II) formate dihydrate from formic acid under solvothermal conditions results in single crystals of anhydrous manganese(II) formate Mn(O2CH)2, and the structure of this phase has been determined by X‐ray diffraction. The same product can be obtained by solid‐state dehydration of single crystals of manganese formate dihydrate, giving crystals that, although of poor quality, still allow for a single crystal structure determination. The structural relationship between the hydrated and anhydrous phases and the nature of the transformation have been determined. Given the nature of the rearrangement involved in the solid‐state reaction, it is remarkable that a crystalline product is obtained. Magnetic measurements of the anhydrous manganese(II) formate show it to be a three‐dimensional antiferromagnet. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)