Thermal decomposition of barium oxomolybdenum(VI) oxalate

A new molybdenum(VI) oxalato complex, BaMoO₃(C₂O₄)]·3H₂O (BMO), was prepared and characterized by chemical analysis and infrared spectral studies. Thermal decomposition studies were made using thermogravimetry and differential thermal analysis. Dehydration reactions take place up to 280°C in three stages with loss of one half, one and a half and one mole of water per mole of BMO, respectively. Decomposition of oxalate takes place between 280 and 435°C in a single step to give BaMoO₄ as the end product, which was characterized by chemical analysis, infrared and X-ray studies. The X-ray diffraction pattern of BMO shows that it is an amorphous compound. A chain structure containing MoO₆ octahedra linked through oxygen is proposed on the basis of the infrared absorption spectrum.