A Monomeric Thallium(I) Amide in the Solid State:  Synthesis and Structure of TlN(Me)Ar^Mes₂ (Ar^Mes₂ = C₆H₃-2,6-Mes₂)

Reaction of TlCl and [LiN(Me)Ar^Mes₂]₂ [Ar^Mes₂ = C₆H₃-2,6-(C₆H₂-2,4,6-Me₃)₂] in Et₂O generated the thallium amide, TlN(Me)Ar^Mes₂ (1). X-ray data showed that it has a monomeric structure with an average Tl−N distance of 2.364(3) Å. There was also a Tl−arene approach [Tl−centroid = 3.026(2) Å (avg)] to a flanking mesityl ring from the terphenyl substituent. DFT calculations showed that this interaction is weak and supported essentially one coordination for thallium. The electronic spectrum of 1 is hypsochromically shifted in comparison to the monomeric TlAr^Trip₂ (Trip = C₆H₂-2,4,6-Prⁱ₃).