Hydroxide complexes of lanthanides--II: samarium(III) in perchlorate medium

From the precipitation borderline in the pM′—pH diagram, determined experimentally under CO₂-free conditions, the stability constants of the mononuclear and polynuclear species of samarium hydroxide have been established. The values found are log*β₁ = −7.5, log*β₂ = −15.0, log*β₃ = −22.7, logβ_{4, 3} = −19.5 and log*K_s0 = 17.5. They refer to fresh precipitates, prepared at room temperature in sodium perchlorate medium with an ionic strength of 1.