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

摘要

Reactiono f M(~tBu)_3 with anthranilic, salicylic an ortho-toluic acids yields [(~tBu)_2M(#mu#-O_2CC_6H_4-2-NH_2)]_2, M = Al (1), Ga (2), [(~tBu)_2Ga(#mu#-O_2CC_6H_4-2-OH)]_2 (3), and [(~tBu)_2Ga(#mu#-O_2CC_6H_4-2-Me)]_2 (4), respectively. Reaction of anthranilic acid with two equivalents of Al(~tBu)_3 allows for the isolation of (~tBu)_2Al(#mu#-O_2CC_6H_4-2-NH_2)Al(~tBu)_3 (5). Compounds 1-5 have been characterized by NMR and IR spectroscopy, mass spectrometry, and X-ray crystallography. The presence of intra-molecular hydrogenbonding,incompounds 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.