Homoleptic Heavy Alkaline Earth and Europium Triazenides

The σ-bond metathesis reaction between PhSiH3 and the heteroleptic metal pentafluorophenyl compounds [Dmp(Tph)N3MC6F5(thf) n ] (Dmp = 2,6-Mes2C6H3 with Mes = 2,4,6-Me3C6H2; Tph = 2-TripC6H4 with Trip = 2,4,6- i Pr3C6H2; n = 1, 2; M = Sr, Ba, Eu) supported by sterically crowded, biphenyl- and terphenyl-substituented triazenido ligands afforded the first homoleptic stontium, barium, and europium triazenides [M{N3Dmp(Tph)}2] {M = Sr (2), Ba (4), Eu (5)}. Crystallization of 2 from an n-heptane/1,2-dimethoxyethane mixture gave the complex [Sr{N3Dmp(Tph)}2(dme)] (3). All new compounds have been characterized by 1H and 13C NMR spectroscopy (not 5), elemental analysis, IR spectroscopy (5 only), and X-ray crystallography. In the solid-state structures, the first coordination sphere of the metal cations consists of four nitrogen atoms of the two bidentate triazenide ligands. Additional metal-ηn-π-arene-interactions of different hapticity n (n = 3−6) are observed to the flanking arms of the terphenyl substituents.