The series of neopentylaluminum compounds, Al (CH2CMe3) 3, A1 (CH2CMe3) 2H, A1 (CH2CMe3l2Br,(Me3CCHJwPh2, and (Me3CCHJ2AlN (Me) H, have been prepared by reactions typical in organoaluminum chemistry and characterized by elemental and/or group analysis, cryoscopic molecular weight measurements in benzene solution, and IR and NMR spectroscopic data. All compounds in this series, except Al (CH2CMe8) 3, are associated ...