For 1-Ln, the ATR-IR spectra feature aliphatic C-H stretches within the expected wavenumber range (3000-2800 cm -1 ). Additionally, one broad band is present in the region corresponding to a bridging bidentate BH4 -group (ca. 2250 cm -1 ); no peaks for terminal B-H stretches are observed. DFT calculations were performed on the diamagnetic Y analogs of the cations of 2-Dy, 3-Dy and 4-Dy