Hydrogen-1 nuclear magnetic resonance studies of exchange reactions between complexes MR3·M′R′3 and their components. Part III. The systems dimethylphenylphosphine–, dimethyl(dimethylamino)phosphine–, and dimethyl-t-butylphosphine– trimethylborane, and trimethyl-phosphine–dimethylphenylborane

Abstract

Dimethylphenylborane has been prepared from BMe₂Cl and HgPh₂, and its vapour pressure measured over a range of temperature. The ¹H n.m.r. band-shape method has been used to determine exchange parameters for the systems PMe₂Ph·BMe₃, PMe₂(NMe₂)·BMe₃, PMe₃·BMe₂Ph, and PMe₂Bu^t·BMe₃. Reactions between complex and an excess of either donor or acceptor proceed by a dissociative mechanism. In dichloromethane at 27 °C, basicities towards BMe₃ decrease in the order NMe₃∼ PMe₃ > PMe₂Bu^t∼ PMe₂(NMe₂) > PMe₂Ph P(CH₂Ph)₃ > PMe₂(CF₃)∼ PMe₃O ∼ PMePh₂.