Synthesis of micro- and nanosized manganese oxides from hydrated manganese oxalates and products of their chemical modification with ethylene glycol

The reactions of ethylene glycol with manganese oxalates MnC2O4 · 2 H2O and MnC2O4 · 3H2O on heating in air were studied. At temperature below 100°C, ethylene glycol was found to displace water from oxalates to give a new solvate compound according to the reaction MnC2O4 · nH2O + HOCH2CH2OH = MnC2O4(HOCH2CH2OH) + nH2O↑. The crystals of the solvates retain the morphology of the initial oxalates, which is then inherited by the products of their thermolysis. Thus, thermolysis of MnC2O4 · 3H2O and MnC2O4(HOCH2CH2OH) having quasi-unidimensional structure gave Mn3O4 and Mn2O3 nanowhiskers in air and MnO in an inert gas environment. Heating of MnC2O4 · nH2O in ethylene glycol at temperatures above 100°C results in anhydrous manganese oxalate.