Synthesis and characterization of methylzinc tri(tert-butyl)silylphosphanide as well as related sodium and potassium phosphanylzincates

The reaction of dimethylzinc and tri(tert-butyl)silylphosphane in toluene yielded dimeric methylzinc tri(tert-butyl)silylphosphanide (1) which crystallized tetrameric. Compound 1 was deprotonated with sodium in DME and the solvent-separated dimeric ion pair [(dme)(3)Na](+) [(dme)Na(MeZn)(2)(mu-PSitBu(3))(2)](-) (2) was isolated. The reaction of I in THF with two equivalents of potassium and one equivalent of tri(tert-butyl)silylphosphane gave dimeric [{tBu(3)Si(H)P}{(thf)(2)K}(2)(MeZn)(PSitBu(3))](2) (3). Both of these phosphanylzincates contain Zn2P2 cycles with Zn-P bond lengths of approximately 237 pm, whereas in 1 larger Zn-P bond lengths of 248.5 pm were found due to the larger coordination numbers of the phosphorus and zinc atoms.