Synthesis and structural characterisation of alkylaluminium and alkylgallium pinacolates
摘要:
The influence of the steric repulsion of ligands on the structure of alkylaluminium and alkylgallium 2,3-dimethylbutane-2,3-diolates (pinacolates) has been studied. Reaction of Me3Al and pinacol afforded the compound Me5Al3[OC(CH3)(2)C(CH3)(2)O](2) (1) possessing two diolate liQands. The treatment of pinacol with the more sterically hindered (Bu3Al)-Bu-t resulted in the formation of aluminium tripinacolate (Bu3Al3)-Bu-t[OC(CH3)(2)C(CH3)(2)O](3) (2) as the only product. In contrast, the reaction of the less reactive (Bu3Ga)-Bu-t with pinacol stopped at the stage of the compound (Bu3Ga2)-Bu-t[OC(CH3)(3)C(CH3)(2)O] [OC(CH3)(3)C(CH3)(2)OH] (3), which is an intermediate product of the reaction of 1,2-diols with group 13 trialkyls. Compounds 1, 2 and 3 were crystallographically characterised. (c) 2007 Elsevier Ltd. All rights reserved.