Dihydrogen Activation by Lithium‐ and Sodium‐Aluminyls.

To date, aluminyl anions have been exclusively isolated as their potassium salts. We report herein the synthesis of the lithium and sodium aluminyls, M2[Al(NONDipp)]2 (M=Li, Na. NONDipp=[O(SiMe2NDipp)2]2−; Dipp=2,6‐iPr2C6H3). Both compounds crystallize from non‐coordinating solvent as "slipped" contacted dimeric pairs with strong M⋅⋅⋅π(aryl) interactions. Isolation from Et2O solution affords the monomeric ion pairs (NONDipp)Al‐M(Et2O)2, which contain discrete Al−Li and Al−Na bonds. The ability of the full series of Li, Na and K aluminyls to activate dihydrogen is reported. [ABSTRACT FROM AUTHOR]