Lewis Acid-Base Studies of Triorganogallium Compounds with Organophosphines

摘要

The relative Lewis acidities of a series of triorganogallium compounds GaR3 (R =Me, Et, CH2CMe3, CH2SiMe3, CH2CMe2Ph and C6H2Me3) toward a common Lewis base HPPh2 and the relative Lewis basicities of a series of organophosphines which incorporate an acidic hydrogen HPRR' (PRR' = PPh2, P(C6H11)2, PEt2 and P(H)(C6H11)) toward a common Lewis acid Ga(CH2CMe3)3 have been investigated and compared. Cryoscopic molecular weight data permitted an evaluation of the equilibrium constant for the dissociation of each of the adducts. The 31P NMR spectral data which were consistent with the molecular weight data were also used to study the relative rates of hydrocarbon elimination reactions to form (R2GaPRR')2.