MONOMERIC PHOSPHANYLGALLANES - SYNTHESIS AND STRUCTURAL CHARACTERIZATION

The monomeric phosphanylgallanes R2GaPR'R '' (R = tmp, Mes; R' = H, tB u; R '' = Mes, tBu), the diphosphanylgallane MesGa(PtBu2)(2), and diph osphandiylbisgallane [tmp(2)GaP-(tBu)](2) have been synthesized from a lkali metal phosphides and substituted gallium chlorides. Low-temperat ure NMR studies of the phosphanylgallanes reveal no barrier to rotatio n about the gallium-phosphorus bond. Analysis of the crystal structure s of tmp(2)GaPtBu(2), Mes(2)GaPtBu(2), MesGa(PtBu2)(2) and [tmp(2)GaP( tBu)](2) confirms the monomeric nature of these molecules. The gallium -phosphorus bond lengths are found to be 237.5, 233.5, 235.4 pm (avera ged), and 242.3 pm, respectively, with all phosphorus atoms being pyra midally coordinated.