Quinone complexes of aluminum: Synthesis and structures

Reactions of aluminum metal with 3,6-di-tert-butyl-o-benzoquinone (3,6-Q) in various solvents gave aluminum tris-o-semiquinolate and catecholate. The metal catecholate underwent partial hydrolysis in the presence of water. The dimeric complex [(Cat)Al(OH)Bipy]₂ × 4C₂H₄Cl₂ (Cat is the 3,6-Q dianion and Bipy is 2,2-bipyridyne) with bridging OH groups was isolated and characterized by X-ray diffraction. A reaction of aluminum with o-quinone in the presence of molecular iodine yielded the dimeric catecholate iodide [(Cat)₂Al(Et₂O)₂]AlI₂. The structure of the latter was confirmed by X-ray diffraction. An aluminum catecholato-o-semiquinolate complex was obtained by an exchange reaction between [(Cat)₂Al(Et₂O)₂]AlI₂ and thallium o-semiquinolate.