Hydrogen and Dihydrogen Bonding as Important Features of the Reactivity of the Bridging Hydride in Pyrazolate-Bridged Dialuminum Complexes

Abstract

Treatment of diisobutylaluminum hydride with 3,5-disubstituted pyrazoles in 2:1 stoichiometry affords the bridging hydride complexes [(μ,η 1:η 1 -R 2 pz)(AliBu 2 ) 2 (μ-H)]. A theoretical study of the reaction of [(μ,η 1:η 1 -R 2 pz)(AliBu 2 ) 2 (μ-H)] with methanol predicts that the reaction proceeds by way of an intermediate containing a strong dihydrogen bond, suggesting that dihydrogen bonding is an important feature of the reactivity of organoaluminum hydrides.