Paramagnetic aluminium–1,4-di-t-butyl-1,4-diazabutadiene (dbdab) complexes derived from metal vapours and/or metal hydrides: crystal structures of [Al(dbdab)2] and [Al(dbdab){N(But)CH2}2]

Abstract

Reaction of aluminium vapour or LiAlH₄–aluminium metal–hexane with 1,4-di-t-butyl-1,4-diazabutadiene (dbdab) yields dark green [Al(dbdab)₂](1), whereas AlH₃·NMe₃ with dbdab in hexane at –80°C yields the corresponding hydroalumination product [Al(dbdab){N(Bu^t)CH₂}₂](2) as a yellow solid; although both compounds are paramagnetic, XPS (solid) and EPR (solution) spectroscopy, and X-ray structure determinations support formally Al^III centres with the unpaired electron ligand-centred.