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, M [Al(NON )] (M=Li, Na. NON =[O(SiMe NDipp) ] ; Dipp=2,6-iPr C H ). Both compounds crystallize from non-coordinating solvent as "slipped" contacted dimeric pairs with strong M⋅⋅⋅π(aryl) interactions. Isolation from Et O solution affords the monomeric ion pairs (NON )Al-M(Et O) , 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.