The repulsive interactions cause signs of rotational hindrance regarding the DMS groups in the 1 H and 13 C NMR spectra. Considering rotatable silyl groups, the compound [FeC10DMS10] (6) should show one signal for the magnetically equivalent DMS methyl protons in the 1 H and C NMR spectrum, respectively. However, two signals at δ = 0.76 and 0.09 ppm with an integral ratio of 1:1 in the 1 H and at δ = 2.41 and -0.18 ppm in the C spectrum are observed instead, as the pairs of methyl groups do not resolve together and are consequently magnetically inequivalent, despite chemical equivalence as indicated by the molecular structures. Similar behavior is observed for compounds 5 and 4b with [C5(DMS)4H] -ligands. The metallocenes with threefold silylated cyclopentadienyl ligands exhibit lower rotational barriers for the silyl groups next to the unsubstituted position. Hence, heptasilyl isomers 3a and 3b do not show the expected four methyl signals in their C NMR spectra, but instead six signals, while octasilyl compound 4a exhibits four differentiated C signals instead of three expected in the absence of rotational hindrance.