Synthesis, Structure, and Reactivity of a Superbulky low‐Valent β‐diketiminate Ga(I) Complex

A low‐valent Ga I complex with the superbulky β ‐diketiminate ligand DIPeP BDI (HC[C(Me)N−DIPeP] 2 , DIPeP=2,6‐C(H)Et 2 ‐phenyl)) was obtained by reduction of ( DIPeP BDI)GaI 2 ( 1 ) with KC 8 in toluene. Considering that (BDI)Ga I and analogue (BDI)Al I complexes are prone to decomposition and can generally only be obtained in low yields (20–40 %), the quantitative formation of ( DIPeP BDI)Ga I ( 2 ) is remarkable and no doubt related to its excellent thermal stability even in refluxing toluene. Although the low‐valent metal center in 2 is sterically protected by the superbulky DIPeP BDI ligand, it is readily oxidized by N 2 O to give intermediate ( DIPeP BDI)Ga=O which readily decomposed by abstracting a proton from the backbone Me‐substituent. Reaction with trimethylsilyl azide gave an intermediate imido complex ( DIPeP BDI)Ga=N(SiMe 3 ) 2 which reacted with a second equivalent of Me 3 SiN 3 to a mixture of an azide/amido complex ( DIPeP BDI)GaN 3 [N(SiMe 3 ) 2 ] ( 4 ) and a tetrazagallole complex ( DIPeP BDI)Ga[N 4 (SiMe 3 ) 2 ] ( 5 ) in a 1 : 2 ratio. Whereas the azide/amido complex 4 could be structurally characterised, the tetraazagallole complex 5 was identified by NMR spectroscopy. DFT calculations on ( DIPeP BDI)Ga I ( 2 ) and its reaction products complement this study.