Synthesis of Lewis Acid-Base Adducts Between Potassium Dihydrogenpnictogenides and Group 13 Lewis Acids.

Lewis acid-base adducts between potassium dihydrogenpnictogenides [K(18c6)PnH2] (Pn=P, As) and Trialkylgallanes (GaMe3, GaEt3, GatBu3) as well as BH3 were synthesized. In the course of these investigations, we were able to fully characterize a row of compounds of the type [K(18c6)(thf)0-2][PnH2(ER3)2] (E=B: R=H; E=Ga: R=Me, Et, tBu). Based on the successful syntheses of these species, we also synthesized several compounds of the composition [K(18c6)(thf)0-2][Pn(SiMe3)2(ER3)n] (n=1, 2) starting from [KPn(SiMe3)2] (Pn=P and As) and ER3 (E=B, Al, In: R=Me; E=Ga: R=Me, Et, tBu). All isolated compounds, were examined by NMR spectroscopy, infra-red spectroscopy and elemental analysis. A selection of the compounds presented were also examined by means of X-ray structure analysis on the single crystal. The obtained adducts of negatively charged [PnH2]- and [Pn(SiMe3)2]- fragments with Lewis acids are a class of compounds that has scarcely been investigated to date.