SYNTHESIS AND MOLECULAR-STRUCTURE OF AN ORTHOMETALATED AMINOGALLANE, [MEGAN(CH2C6H4)(CH(2)PH)](2)

Monitoring the thermolysis reaction of Me(3)Ga with HN(CH(2)Ph)(2) in toluene with multinuclear NMR spectroscopy indicates the initial forma tion of [Me(2)GaN(CH(2)Ph)(2)](2) via 1,2elimination of CH4 followed b y additional 1,2-elimination steps that give the orthometalated galliu m dimer [MeGaN(CH2C6H4)(CH(2)Ph)](2) in 65% yield. This is the first r eported example of orthometalation of an aromatic ring carbon by galli um. Because [MeGaN(CH2C6H4)(CH(2)Ph)](2) forms prior to the complete c onversion of (PhCH(2))(2)NH . GaMe(3) to [Me(2)GaN(CH(2)Ph)(2)](2), th ermolysis of a Me(3)Ga/HN(CH(2)Ph)(2) mixture is not a viable route to [Me(2)GaN(CH(2)Ph)(2)](2). Instead it was prepared by a salt eliminat ion reaction. The single-crystal X-ray diffraction analysis establishe s the dimeric nature of the orthometalated compound and indicates a st ructure that is consistent with the NMR chemical shift assignements ob tained using both 1-D and 2-D NMR techniques.