Lanthanide triiodides LnI3 (Ln = Nd, Sm) were synthesized by an improved method and used for the synthesis of complexes with β-diketiminate (nacnac) ligand [Ln(LDipp)I2(THF)2] (LDipp = HC(C(NDipp)Me)2 −, Dipp = 2,6-Diisopropylphenyl; Ln = Nd, 1a; Sm, 1b). These complexes were crystallized as solvates with THF or toluene, depending on the solvent, while the Nd complex 1a was also shown to reversibly lose one of coordinated THF molecules upon recrystallization from toluene at elevated temperatures. The diiodide complexes 1 were used as convenient precursors to thiolate complexes of the types [Ln(LDipp)(SPh)2(THF)] (Nd, 2a; Sm, 2b) and [Ln(LDipp)(S-2-Py)2] (Nd, 3a; Sm, 3b), obtained by salt metathesis reactions with KSPh and KS(2-Py), respectively. The phenylthiolate complexes 2 have formal coordination number (CN) of 6, where the 6th position is occupied by a Ph ring which is placed close to the Ln centre and plays a role of a ligand even in the presence of THF. The pyridilthiolates 3 have CN of 6 and contain no coordinated THF molecules. All compounds were characterized by single crystal X-ray diffraction, elemental analysis, IR spectroscopy. IR bands characteristic for all types of ligands in the complexes are discussed.