Cs[Yb(NPPh3)4] – ein homoleptischer Phosphaniminato‐Komplex des Ytterbiums

Cs[Yb(NPPh₃)₄] – a Homoleptic Phosphoraneiminato Complex of Ytterbium Cesium tetrakis(phosphoraneiminato)ytterbate, Cs[Yb(NPPh₃)₄] ( 1 ) has been prepared by the reaction of the dimeric complex [Yb(NPPh₃)₃]₂ with CsNPPh₃ in thf solution. 1 crystallizes from thf solution to give colourless moisture sensitive crystals which contain three molecules thf per asymmetric unit. According to the crystal structure determination 1 forms a dimeric ion ensemble [Cs{Yb(NPPh₃)₄}]₂ in which the Cs⁺ ions connect the [Yb(NPPh₃)₄]^– ions via Cs…N bridges. The ytterbium atoms are distorted tetrahedrally coordinated by the nitrogen atoms of the phosphoraneiminato ligands (NPPh₃^–) with short Yb–N‐bond lengths between 212.1 and 221.9(8) pm. The included thf molecules are without bonding contacts with the complex. [Cs{Yb(NPPh₃)₄}]₂ · 6 thf: Space group P 1, Z = 2, lattice dimensions at 193 K: a = 1837.2(2), b = 2041.5(2), c = 2095.8(2) pm, α = 79.953(13)°, β = 79.364(11)°, γ = 88.239(12)°, R = 0.0625.