Gallane Complexes with Amido−Amine Ligands

Gallane complexes bearing amido−amine ligands −N(R)CH<sub>2</sub>CMe<sub>2</sub>CH<sub>2</sub>NMe<sub>2</sub> [R = H or SiMe<sub>3</sub> (TMS)], {H<sub>2</sub>Ga[N(H)CH<sub>2</sub>CMe<sub>2</sub>CH<sub>2</sub>NMe<sub>2</sub>]}<sub>2</sub>, <b>1</b>, H<sub>2</sub>Ga[N(TMS)CH<sub>2</sub>CMe<sub>2</sub>CH<sub>2</sub>NMe<sub>2</sub>], <b>2</b>, {H(Cl)Ga[N(H)CH<sub>2</sub>CMe<sub>2</sub>CH<sub>2</sub>NMe<sub>2</sub>]}<sub>2</sub>, <b>3</b>, {[(TMS)<sub>2</sub>N](H)Ga[N(H)CH<sub>2</sub>CMe<sub>2</sub>CH<sub>2</sub>NMe<sub>2</sub>]}<sub>2</sub>, <b>4</b>, and HGa[N(TMS)CH<sub>2</sub>CMe<sub>2</sub>CH<sub>2</sub>NMe<sub>2</sub>]<sub>2</sub>, <b>5</b>, were synthesized from the reactions of the quinuclidine adducts of mono- and dichlorogallane with the corresponding lithium amides. Structural determinations of compounds <b>1</b>, <b>3</b>, and <b>4</b> showed all were dimeric with bridging amido groups. Rather than bond to gallium the tertiary amine groups in <b>1</b> and <b>4</b> were hydrogen-bonded to the amido N−H. In the structure of compound <b>3</b> the amine group occupied an axial position in the trigonal bipyramidal geometry of the five-coordinate gallium. The results were rationalized in terms of the steric and electronic properties of gallium ligands.