| Abstract: | The Reaction of Ytterbium with N‐iodo‐triphenylphosphaneimine. Crystal Structures of Yb2I(THF)2(NPPh3)4] · 2 THF, YbI2(HNPPh3)(DME)2], and {YbI2(DME)2}2(μ‐DME)] When treated with ultrasound, the reaction of ytterbium powder with INPPh3 in tetrahydrofuran leads to YbI2(THF)4] and to the mixed‐valence phosphoraneiminato complex Yb2I(THF)2(NPPh3)4] · 2 THF ( 1 ), which forms red single‐crystals. In the analogous reaction in 1,2‐dimethoxyethane (DME) only the ytterbium(II) iodide solvates YbI2(HNPPh3)(DME)2] ( 2 ) and {YbI2(DME)2}2 · (μ‐DME)] ( 3 ) can be isolated, which form yellow single crystals. All compounds were characterized by crystal structure analyses. 1 : Space group P1, Z = 2, lattice dimensions at –80 °C: a = 1337.6(5), b = 1389.6(5), c = 2244.2(17) pm; α = 86.11(7)°, β = 88.06(7)°, γ = 88.63(4)°; R = 0.0759. In 1 the two ytterbium atoms are connected via the N atoms of two phosphoraneiminato groups (NPPh3–) to form a planar Yb2N2 four‐membered ring. The structure can also be described as an ion pair consisting of YbI(THF)2]+ and Yb(NPPh3)4]–. 2 : Space group P21, Z = 2, lattice dimensions at –80 °C: a = 811.9(1), b = 1114.0(1), c = 1741.3(1) pm; β = 95.458(5)°; R = 0.0246. 2 forms molecules in which the ytterbium atom is coordinated in a pentagonal‐bipyramidal fashion with the iodine atoms in the axial positions. The O atoms of the two DME‐chelates and the N atom of the phosphaneimine ligand HNPPh3 are in the equatorial positions. 3 : Space group P1, Z = 2, lattice dimensions at –70 °C: a = 817.5(1), b = 1047.7(1), c = 1115.5(2) pm; α = 90.179(10)°, β = 97.543(15)°, γ = 91.087(12)°; R = 0.0317. 3 has a dimeric molecular structure, in which the two fragments {YbI2(DME)2} are connected centrosymmetrically via a μ‐DME bridge. As in 2 , the ytterbium atoms are coordinated in a pentagonal‐bipyramidal fashion with the iodine atoms in the axial positions, as well as with the two DME chelates and with one O atom each of the μ‐DME ligand in the equatorial positions. |
