Di(tert-butyl) aluminum, -gallium and -indium β-diketonates and β-diketiminates, reactions with oxygen and formation of an unprecedented peroxo-rich hexaperoxotriindium compound

Reactions of 1,3-di(tert-butyl) acetylacetone (2,2,6,6-tetramethyl-3,5-heptanedione), ((t)Bu(2)acac)H, with tri(tert-butyl) aluminum, -gallium and -indium afforded selectively the corresponding di(tert-butyl) metal derivatives ((t)Bu(2)acac) (MBu2)-Bu-t [M = Al (1), Ga (2), In (3)] by release of isobutane. Likewise, diphenyl-beta-diketamine [Ph-N=C(Me)](2)CH2, (Ph(2)nacnac)H, reacted with (MBu3)-Bu-t to generate the compounds (Ph(2)nacnac)(MBu2)-Bu-t [M = Ga (4), In (5)], which represent the first di(tert-butyl) complexes of gallium and indium with a beta-diketiminato ligand. The reaction of 1 with molecular oxygen afforded an aluminum bisalkoxide (6) that is a dimer in the solid state. An indium peroxide (7) was reproducibly obtained in small quantities by the reaction of 3 with excess oxygen at 0 degrees C. Structure determination revealed a fascinating peroxo-rich triindium compound with four bridging and two terminal tert-butylperoxo moieties. The molecular core consists of an In3O7 skeleton. In contrast, THF/hexane solutions of 4 and 5 were stable towards oxygen, but slowly hydrolyzed on contact with water. (c) 2018 Elsevier B.V. All rights reserved.