Replacing the Cp-hydrogen atoms with DMS groups so that the fivefold axis of the Cp ligand is retained results in two possible conformers (of D5 and S10 symmetry, respectively) which differ in the relative orientation of the Si-H bonds on the two rings. The electronic energy difference between the two conformers vanishes, consistent with the experimentally observed disorder in the crystal structure of 6 (ESI, Figure ). Based on our calculations, these two conformers lead to qualitatively different spectra (ESI, Figure ). A low-energy shoulder is found for the S10 structure but not for the D5 structure. However, the D5 conformer exhibits much larger intensities, as the 1 A1 → 1 E1 transition becomes dipole-allowed. We suspect that the shoulder observed experimentally (Figure ) may be due to a significant contribution to these low-energy regions of the spectrum from further areas on the conformational energy surface that are accessed dynamically at experimental temperatures. Contributions from different, energetically similar structures may be expected also for the hepta-, octaand nonasilylated compounds, explaining their comparable band shapes.