Group 13 cation formation with a potentially tridentate ligand

A potentially tridentate ligand, Phensal(tBu)H-3, was prepared by the conde nsation of 1 equiv of phenylenediamine with 3,5-di-tert-butylsalicylaldehyd e, When 1 equiv of this new ligand is added to AlMe3 [[Phensal(tBu)HAlMe]]( 2) (1) results. In contrast, this reaction with GaMe3 produces [Phensal(tBu )H-2]GaMe2 (2). When 1 or 2 equiv of Phensal(tBu)Hs is combined with Et2AlC l, the,complex [Phensal(tBu)](2)AlCl (3) forms. However the same reaction w ith Me2GaCl leads to. [Phensal(tBu)Ha] Ga(Me)Cl (4). A cationic complex, {[ Phensal(tBu)](2)Al}Cl-+(-) (5), is formed when 3 is dissolved in MeOH. The MeOH apparently mediates the formation of the cation but does not coordinat e the cationic metal, when the solvent is removed, 5 reverts back to neutra l 3. When 3 is combined with GaCl3 in toluene, another cationic complex, {[ Phensal(tBu)H-2](2)Al}+GaCl4- (6), is formed. In a similar manner, {[Phensa l(tBu)H-2](2)Al}+Me2AlCl2- (7) is formed by adding Me2AlCl to 3. The compou nds were characterized by mp, elemental analyses, IR, H-1 smd Al-27 NMR, an d in the case of 2, 5, and 6 single-crystal X-ray analysis.