Thermal investigations of dehydration of lanthanide(III) 5-nitroanthranilates

The 5-nitro-2-anthranilates of lanthanum(III), samarium(III), terbium(III), erbium(III) and lutetium(III) were obtained as hydrates having 2.5 mol of water molecules per 1 mol of compound. The compounds are isostructural. The processes of dehydration and rehydration were investigated. The first step of dehydration does not cause the change of crystal structure. The entire dehydration gives anhydrous compounds with different structure than the structure of hydrates. However, the dehydration of La, Sm, Tb and Er is reversible - the rehydration process gives the complexes having the same crystal structure as the initial compounds. Only the anhydrous lutetium complex under the influence of moisture does not give the starting compound.