The UV-Vis spectral data for Pr(SCN), NaSCN and Pr(NO3)3 LiNO3 are rep
orted for 17, 25, 35, 50, and 61.3-degrees-C. The calculated absolute
values of the stability constants for the Pr nitrato complexes are hig
her than those for thiocyanates. The equilibria in outer vs. inner sph
ere complexation in the system are discussed,