Synthesis of 1,6-Bis( trimethylsilylamino) benzene- Substituted Aluminum Hydrides: The Characterization of a Product from Ring- Opening Reaction of Tetrahydrofuran

The reaction of 1, 6-bis(trimethylsilylamino)benzene (LH2) (1) in toluene with H3Al center dot NMe3 yielded the aluminum monohydride with coordinate NMe3 of composition [1, 6-(Me3SiN)(2)C6H4]AlH(NMe3) (2). However, the same reaction in THF resulted in the ring opening of THF with formation of {[1, 6-(Me3SiN)(2)C6H4]AlH}(2)O(CH2)(4)NMe3 (3) in good yield. Both the spectroscopic data in solution as well as the X-ray crystallographic data confirmed that a THF molecule underwent a ring-opening reaction. Compound 2 is the first monomeric aluminum hydride compound containing the 1, 6-bis(trimethylsilylamino)benzene. Compound 3 exhibits an intermolecular zwitterion of composition O-(CH2)(4)NMe3+ between two aluminum atoms. Complexes 2 and 3 were characterized by H-1 NMR spectroscopy, elementary analysis, and single-crystal X-ray diffraction studies.