Drei neue Ethanidiodide des Lanthans: La 5 I 9 (C 2 ), La 6 I 10 (C 2 ) und La 10 I 15 (C 2 ) 2

Three New Ethanide Iodides of La: La 5 I 9 (C 2 ), La 6 I 10 (C 2 ) and La 10 I 15 (C 2 ) 2 The reaction of La, LaI 3 und C (4 : 5 : 3) yields the unknown compounds La 5 I 9 (C 2 ) at 800 °C, La 6 I 10 (C 2 ) at 850 °C, and La 10 I 15 (C 2 ) 2 at 900 °C. They crystallize in the triclinic space group $P{\bar 1}$ with a = 8.006(2) Å, b = 10.088(2) Å, c = 14.383(3) Å, α = 79.34(3)°, β = 80.75(2)° and γ = 85.07(3)° for La 5 I 9 (C 2 ), a = 9.687(1) Å, b = 9.728(1) Å, c = 7.955(1) Å, α = 97.34(1)°, β = 105.56(1)° and γ = 107.81(1)° for La 6 I 10 (C 2 ) and a = 9.747(1) Å, b = 10.655(1) Å, c = 11.736(1) Å, α = 93.68(1)°, β = 114.44(1)° and γ = 109.28(1)° for La 10 I 15 (C 2 ) 2 . As characteristic building units the crystal structure of La 5 I 9 (C 2 ) contains trigonal bipyramids of La atoms, La 6 I 10 (C 2 ) La octahedra, and La 10 I 15 (C 2 ) 2 La double octahedra. These La building units are centered by C 2 dumbbells with d(C‐C) ranging from 1.41(1) Å to 1.47(1) Å. The black compounds are sensitive to moisture.