Keywords: Ab initio calculations / Lanthanides / π interactions / S ligands / YtterbiumThe base-free, hydrocarbon-soluble complexes M(SAr*) 2 (4a: M = Eu, orange; 4b: M = Yb, purple; Ar* = 2,6-Trip 2 C 6 H 3 ; Trip = 2,4,6-iPr 3 C 6 H 2 ) have been prepared by a protolysis reaction of the Grignard-analogous compound RLnI (R = 2-F 3 CC 6 H 4 ) with HSAr*. Compound 4b has been characterized by melting point, elemental analysis, 1 H, 13 C, and 171 Yb NMR, IR spectroscopy, UV/Vis spectrophotometry, mass spectrometry, and X-ray crystallography. Additionally, the purple Yb III complex YbI 2 (SAr*)(THF) 3 (3) and the yellow DME adduct Yb(SAr*) 2 (dme) 2 (5) have been synthesized and characterized by X-ray crystallography. The solid-state structures of 4a and 4b (as THF or benzene hemisolvates) show monomeric units with the metal atom bonded to two terminal