spin coupling could be observed in the 31P NMR spectrum (1JPLi = 84 Hz). Reaction of potassium phosphanide [(SiMe3)3Si]SiMe3PK with SiCl4 led to the formation of [(SiMe3)3Si](SiMe3)P(SiCl3) (4), which could be successfully characterized with X-ray diffraction and multinuclear NMR spectroscopy. SiP bond lengths vary between 218 pm (SiCl3) and 230 pm (hypersilyl). Despite these differences, 31P29Si coupling