Donor-Solvent-Dependent Cluster Formation of (C5Me5)SmI2(THF)x‑Type Half-Sandwich Complexes

In this study, we demonstrate the structural variety of the Cp*SmIy system with respect to the amount of donor molecules (THF) present. The reaction of SmI2(THF)2 with 0.5 equiv of bis­(pentamethyl­cyclopentadienyl)­lead­(II), PbCp*2, in THF gives the highly solvated monomeric complex Cp*SmI2(THF)3, when crystallized from THF. The same reaction performed in n-hexane followed by crystallization from toluene gave the partially solvated trimetallic complex [Cp*3Sm3I­(μ2-I)3­(μ3-I)2(THF)2]. Recrystallization of the Sm3 cluster from either C6D6 at ambient temperature or toluene at −40 °C produced the tetrametallic complex [Cp*4Sm4I­(μ2-I)4­(μ3-I)2(μ4-I)­(THF)]. Reaction of SmI2, obtained via treatment of SmI2(THF)2 with excess AlEt3 in n-pentane, with 0.5 equiv of PbCp*2 in toluene led to the donor-free mixed-valent pentametallic complex [Cp*5Sm5(μ2-I)4­(μ3-I)4(μ5-I)]. All compounds were characterized by single-crystal X-ray structure analysis.