Aluminium and gallium compounds of salicylic and anthranilic acids: examples of weak intra-molecular hydrogen bonding

Reaction of M(Bu-t)(3) with anthranilic, salicylic and ortho-toluic acids y ields [(Bu-t)(2)M(mu -O2CC6H4-2-NH2)](2), M = Al (1), Ga (2), [(Bu-t)(2)Ga( mu -O2CC6H4-2-OH)](2) (3), and [(Bu-t)(2)Ga(mu -O2CC6H4-2-Me)](2) (4), resp ectively. Reaction of anthranilic acid with two equivalents of Al(Bu-t)(3) allows for the isolation of (Bu-t)(2)Al(mu -O2CC6H4-2-NH2)Al(Bu-t)(3) (5). Compounds 1-5 have been characterized by NMR and IR spectroscopy, mass spec trometry, and X-ray crystallography. The presence of intra-molecular hydrog en bonding, in compounds 1-3, is probed by the orientation of the aromatic rings. Compound 5 is proposed to be a Lewis acid stabilized complex of the intermediate in the synthesis of compound 1.