Also of note are the 29 Si satellites in the 31 P{ 1 H} NMR spectra of 2-4. While 2 and 4 show apparent Si satellites, the measured coupling from these satellite peaks does not match that found in the 29 Si NMR spectra. This is likely due to the presence of one spin-active 29 Si nucleus causing the two 31 P nuclei to become magnetically inequivalent, such that the satellite signal is not a simple doublet. For 3, the measured 2 JSiP from the satellites does match the 29 Si NMR spectrum, suggesting that the two P atoms are (closer to) magnetically equivalent in 3. The 31 P{ 1 H} NMR signal for 4 (δP = -209 ppm) occurs significantly downfield of the signals for 2 or 3 (δP = -288 and -284 ppm, respectively), which is consistent with previously published Group 12 bis(silylphosphanido) complexes. The 113 Cd and 199 Hg NMR spectra of 3 and 4 both appear as triplets, with large couplings to phosphorus ( 1 JCdP = 350 Hz, 1 JHgP = 408 Hz).