Reducing hybrid ligand-based alane and chasing aluminium(I): dialane and unusual transient dialumene.

In this work, an alane, [DNIAlH 2 ] (1) (DNI = 3,3-dimethyl-2-[2-methyl-2-(2,6-diisopropyl-aniline)ethenyl]-3 H -indolenine), stabilised by a hybrid ligand was reduced by Jones's Mg(I) ([( Mes BDIMg) 2 ]) and Roesky's Al(I) ([ Dipp BDIAl:]). The resulting dialane compound [{DNI(H)Al} 2 ] (2) was characterised using NMR spectroscopy, mass spectrometry, DFT calculations and single-crystal XRD experiments. The reaction of aluminium dihydride [DNIAlH 2 ] (1) with [ Dipp BDIAl:] at high temperatures gives an intramolecular C(sp 2 )-H bond-activated compound 3. To study the monomeric hybrid ligand-based Al(I), characterisations and computational calculations were performed, which elucidate that compound 5, consisting of two inequivalent aluminium atoms in an Al 2 CN four-membered ring, resulting from the activation of a carbon-nitrogen bond in the reaction of [DNINa] with [(Cp*Al) 4 ].