Six-membered copper bis-(1-salicylideneamino-4,5,6-triaryl-2-pyridone) complexes and a number of 1-arylidene-amino-, 1-phthalimido-, 1-succinimido-, and 1-maleimido-4,5,6-triaryl-2-pyridones have been prepared. Of these, the 1-arylideneamino-derivatives are not hydrolysed by hydrochloric acid, but copper chloride or 2,4-dinitrophenylhydrazine catalyses the formation of the free amine and the corresponding aldehyde.