Different modes of aggregation in organoaluminium and -gallium hydroxylamides

Abstract

The organoaluminium and -gallium hydroxylamides (Me₂GaONMe₂)₂, (tBu₂AlONMe₂)₂, (tBu₂GaONMe₂)₂ and (Me₂AlONⁱPr₂)₂ have been prepared by the reaction of the hydroxylamines Me₂NOH and ⁱPr₂NOH with the trialkylmetal compounds trimethylgallium, tri-^tbutylaluminium and tri-^tbutylgallium, respectively. All compounds have been characterised by NMR spectroscopy (¹H, ¹³C, ¹⁵N, ¹⁷O and ²⁷Al), by mass spectrometry and elemental analyses. The crystal structures of the four compounds have been determined, showing that they all form dimers but with different modes of aggregation: (Me₂GaONMe₂)₂ has a Ga₂O₂N₂ six-membered ring, (^tBu₂AlONMe₂)₂ and (Me₂AlONⁱPr₂)₂ have Al₂O₂ four-membered rings, (^tBu₂GaONMe₂)₂ forms a Ga₂O₂N five-membered ring.