Barium Bis(dimethylsilyl)amide - Adduct vs. Oxo Formation

Silylamide [Ba{N(SiHMe2)(2)}(2)](n) reacts with 1,10-phenanthroline (Phen) in toluene to give the donor adduct [Ba{N(SiHMe2)(2)}(2)(Phen)](2). X-ray structure analysis revealed a dimeric solid-state structure with two bridging silylamido ligands and Ba center dot center dot center dot SiH beta-agostic interactions, which are most pronounced for the terminal silylamido ligands. Treatment of [Ba{N(SiHMe2)(2)}(2)](n) with GaMe3 did not lead to the isolation of putative Lewis acid adduct [Ba(mu-{N(SiHMe2)(2)})(mu-Me)-(GaMe2)] but resulted in the soluble, low aggregated barium oxo complex [Ba(mu(4)-O)(GaMe3)(2)(toluene)](2), which is reminiscent of inverse crown ethers.