The reaction of YbI₂ with KTp^Me2 gives (Tp^Me2)YbI(THF)₂ (1-Yb) as a thermally unstable product. Use of the more hindered KTp^tBu,Me gave (Tp^tBu,Me)LnI(THF)_n (Ln = Sm, n = 2, 2-Sm; Ln = Yb, n = 1, 2-Yb). The crystal structures of both these compounds are reported. Adducts with neutral ligands such as pyridines and isonitriles can be prepared and the crystal structures of [(Tp^tBu,Me)YbIL_n] (L = CN^tBu, n = 1; L = 3,5-lutidine, n = 2) are described. 2-Sm can be oxidized using AgBPh₄ to give [(Tp^tBu,Me)SmI(THF)₂]BPh₄. Compounds 2-Sm and 2-Yb are useful starting materials for the preparation of heteroleptic compounds by metathesis with appropriate potassium reagents. The preparations and characterization of the hydrocarbyls (Tp^tBu,Me)Ln{CH(SiMe₃)₂} (Ln = Sm, 5-Sm; Yb, 5-Yb) and [(Tp^tBu,Me)Ln{CH₂(SiMe₃)}(THF)] (Ln = Yb, 6a-Yb) and the triethylborohydrides [(Tp^tBu,Me)Ln(HBEt₃)(THF)_n] (Ln = Sm, n = 0, 7-Sm; Yb, n = 1, 7-Yb) are reported, as well as the crystal structures of 5-Sm and 5-Yb, and the THF adducts 6a-Yb and [(Tp^tBu,Me)Sm{CH(SiMe₃)₂}(THF)], 5a-Sm.