Utilizing Steric Bulk to Stabilize Molybdenum Aminogermylyne and Aminogermylene Complexes

Two extremely bulky bis­(aryl)­amines, HN­(Ar*)­(Ph) (HLPh) and HN­(Ar*)­(Mes) (HLMes) (Ar* = C6H2{C­(H)­Ph2}2Me-2,6,4; Mes = mesityl), have been prepared by palladium-catalyzed cross-coupling reactions and structurally characterized. These have been utilized in the preparation of the amido-germanium­(II) chlorides, [LPhGeCl] and [LMesGeCl]. Reactions of these, and the known complex, [L′GeCl] (L′ = −N­(Ar*)­(SiMe3)), with Na­[CpMo­(CO)3] have afforded the first examples of structurally characterized two-coordinate molybdenum substituted germylenes, [Cp­(CO)3MoGeN­(Ar*)­(R)] (R = SiMe3 or Ph). The former readily eliminates a molecule of CO when heated or irradiated with UV light to give an unprecedented amino-germylyne complex, [Cp­(CO)2MoGeN­(Ar*)­(SiMe3)]. The spectroscopic and structural data for this complex, in combination with the results of computational studies, show that this compound is best viewed as having a bent Mo–Ge “triple” bond, with little multiple bond character to its Ge–N interaction. Computational studies have also indicated that the Mo–Ge–N bending in the complex is due to the extreme steric bulk of its amido substituent.