2,4-DINITROBENZOATE AND 3,5-DINITROBENZOATE OF CD, MN, NI AND CO

2,4- and 3,5-dinitrobenzoates of Co, Ni, Mn and Co were obtained as hydrated salts with a metal:ligand ratio of 1 : 2. They were found to be trihydrates of a yellow colour for 2,4-dinitrobenzoates and tetrahydrates with colours characteristic of M(2+) ions for 3,5-dinitrobenzoates. The carboxylate group appears to be a bidentate chelating ligand. The NO2 groups do not coordinate with metal ions. Dinitrobenzoates of Co, Ni, Mn and Cd are crystalline compounds characterized by low symmetry and a large size of unit cells. They are unstable compounds that melt above 573 K and decompose explosively. In two steps, they lose the crystallization water molecules, Decomposition of the dinitro complexes yields, as final products, the oxides of appropriate metals. The solubilities in water at 293 K for all complexes are in the order of: 10(-1)- 10(-2) mol dm(-3).