Synthesis and structures of YNiIn2 and Y4Ni11In20

Well-shaped single crystals of YNiIn₂ and Y₄Ni₁₁In₂₀ were obtained by arc-melting of the elements and subsequent slow cooling. Both indides were investigated by X-ray diffraction on powders and single crystals: MgCuAl₂ type, Cmcm, a=431.52(8), b=1042.0(2), c=730.0(1) pm, wR₂=0.0471, 587 F² values, 16 variables for YNiIn₂ and U₄Ni₁₁Ga₂₀ type, C2/m, a=2251.2(4), b=430.77(8), c=1658.5(3) pm, β=124.62(1)°, wR₂=0.0542, 1583 F² values, 108 variables for Y₄Ni₁₁In₂₀. Both structures are built up from three-dimensional NiIn₂] and Ni₁₁In₂₀] networks in which the yttrium atoms fill distorted pentagonal channels. The NiIn₂] network has only Ni–In and In–In contacts, while also Ni–Ni bonding plays an important role in the Ni₁₁In₂₀] network.