The thermal decompositions of Al, Ga, In, Cr, Fe and Bi complexes with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone have been
studied in a nitrogen atmosphere. The thermal stabilities of these complexes follow the sequence Bi<Fe<Ga<In<Cr<Al. In the
cases of Al, Ga and In, a linear relationship was obtained between the melting points of the complexes and the ionic radii
of the central metals.