Hydrolysis of tri-tert-butylaluminum: the first structural characterization of alkylalumoxanes [(R2Al)2O]n and (RAlO)n

In situ1H- and27AL-NMR studies on metallocene catalyst systems?Catalysts for olefin polymerization

“…This resonance was also observed by Nekhaeva et al, 4 while not observed by Sugano et al 5 and Mason et al 6 The chemical shift of TMA is approximately 154 ppm, which confirms the result reported by Sugano et al 5 and Mason et al 6 …”

A DFT quantum-chemical study on the structures and active sites of polymethylaluminoxane

“…These peculiarities impede the studies of the MAO structure and identification of reactive centers which interact with metallocenes forming the catalyst's active centers. Barron et al 16) obtained reliable structural data for tertbutylaluminoxane of composition [(t-Bu)Al(l 3 -O)] 6 . This aluminoxane has been shown to form a three-dimensional oxo-bridged structure (cage structure) comprised by coordinatively saturated aluminium and oxygen atoms (tetraand triple-coordinated, respectively).…”

Aluminoxane co-catalysts for the activation of a bis phenoxyimine titanium (IV) catalyst in the synthesis of disentangled ultra-high molecular weight polyethylene

“…Several structures ranging from linear to complex cage structures have been proposed for example by Sinn [12], based on mass balances and phase separation experiments in the alkylaluminoxanes synthesis; other studies tend to attribute to MAO a cage structure, based on a combination of a tert-butylaluminoxanes crystallographically characterizable structure [13] and computational studies [14]. Compared with the other co-catalysts, such as alkylaluminums or small boranes, the MAO is able to stabilize the negative charge formed upon activation over a larger structure [15], thus resulting in a less 'sticky' ion couple that can accommodate the incoming monomer more easily [10].…”