Hydrolysis of Thorium Nitrides and Carbonitrides

Studies were made on the hydrolysis by water and water vapor of thorium nitrides—ThN, Th₃N₄, Th₂N₂O—and carbonitrides. All the thorium nitrides and carbonitrides were found to decompose in water below 100°C, changing thereby into ThO₂. The order among the thorium nitrides in their propensity toward hydrolysis is: ThC_1-xN_x>ThN>Th₃N₄>Th₂N₂O. Upon hydrolysis, ThN produced NH₃ and H₂, but in the case of the higher nitrides no H₂ was found to evolve.

In the reaction between ThN and water vapor, no higher nitride was produced, in contrast to the case of UN. The difference in behavior between ThN and UN was studied from the standpoint of differences in crystallographic conditions for the transformation from mononitride into higher nitrides. Through the hydrolysis of ThC_1-xN_x in water vapor, products containing C-C, C-C-C and C-N bonds, such as ethane and amines, were found in smaller quantities than for the case of UC_1-xN_x. This fact as well as the difficulty of formation of higher nitrides has resulted in a fairly simple hydrolysis behavior of thorium nitrides.