Reduction of CO 2 with Aluminum Hydrides Supported with Ar-BIAN Radical-Anions (Ar-BIAN = 1,2-Bis(arylimino)acenaphthene).

The reactions of H 2 AlCl with [(dpp-Bian)Na(Et 2 O) n ] and [(Ar BIG -Bian)Na(THF)] produce respective aluminum hydrides supported by radical-anionic 1,2-bis(arylimino)acenaphthene ligands, [(dpp-Bian)AlH 2 ] ( 1) and [(Ar BIG -Bian)AlH 2 (THF)] ( 2 ) (dpp-Bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene); Ar BIG -Bian = 1,2-bis[(2,6-dibenzhydryl-4-methylphenyl)imino]acenaphthene). The reaction of 1 with CO 2 proceeds with reduction of both C═O bonds and results in diolate [{(dpp-Bian)Al(μ-O 2 CH 2 )} 2 ] ( 3 ). Complex 2 reacts with CO 2 to carbonate [{(Ar BIG -Bian)Al(μ-OCH 2 OCO 2 )} 2 ] ( 4 ) that is a result of the insertion of CO 2 into the Al-O bond in diolate species formed initially. Aluminum monohydrides [(dpp-Bian)AlH(X)] (X = Cl, 5 ; Me, 6 ) react with CO 2 to form respective alumoxanes [{(dpp-Bian)AlX} 2 (μ-O)] (X = Cl, 7 and X = Me, 8 ). Compounds 1 - 4 , 7 , and 8 have been characterized by ESR and IR spectroscopy, and their molecular structures have been determined by single-crystal X-ray analysis.