[4-tert-Butyl-2,6-bis-(di-phenyl-meth-yl)phenolato-κO]dieth-yl(tetra-hydro-furan-κO)aluminium.

The title compound, {Al[O-2,6-(Ph2CH)2-4- t BuC6H2]Et2(THF)} or [Al(C2H5)2(C36H33O)(C4H8O)], was formed in the reaction between 4-tert-butyl-2,6-bis-(di-phenyl-meth-yl)phenol and tri-ethyl-aluminum in the presence of THF (THF is tetra-hydro-furan) and recrystallized from hexane. The structure has monoclinic (P21/n) symmetry with a single Al atom in the asymmetric unit. The terminal C atom of one ethyl substituent is nearly equally disordered over two positions. The complex possesses catalytic activity in the ring-opening polymerization of ∊-caprolactone.