Four‐ and Five‐Coordinate Gallium Complexes Stabilized by Bidentate 2‐(Dimethylaminomethyl)Pyrrole Ligand: Molecular Structures of Ga[NC 4 H 3 (CH 2 NMe 2 )‐2] 3 and GaMe 2 [NC 4 H 3 (CH 2 NMe 2 )‐2]

Treatment of GaCl 3 with one equiv of Li[NC 4 H 3 (CH 2 NMe 2 )‐2] (n = 1, 2, 3) in diethyl ether at −78 °C yields GaCl 3‐n [NC 4 H 3 (CH 2 NMe 2 )‐2] n (n = 1, 1 ; n = 2, 2 ; n = 3, 3 ). Compound 1 reacts with two equiv of RLi to afford GaR 2 [NC 4 H 3 (CH 2 NMe 2 )‐2] ( 4a, R=Me; 4b, R=Bu ) via transmetallation. Reacting 2 with one equiv of RLi in diethyl ether, 3 and 4 are formed via ligand redistribution. Variable temperature 1 H NMR spectroscopic experiments reveal that the five‐coordinate gallium compound 3 is fluxional and results in a coalescence temperature at 5 °C, at which ΔG ≠ is calculated at ca. 10.4 Kcal/mole. All the new compounds have been characterized by 1 H and 13 C NMR spectroscopy and the structures of compounds 3 and 4a have also been determined by X‐ray crystallography.