Pyridin‐Komplexe von Seltenerd‐Trichloriden. Synthese und Kristallstrukturen von [YCl3(Py)4] und [LnCl3(Py)4] · 0,5 Py mit Ln = La und Er

Pyridine Complexes of Rare Earth Element Trichlorides. Syntheses and Crystal Structures of YCl₃(py)₄] and LnCl₃(py)₄] · 0.5 py with Ln = La and Er The pyridine complexes YCl₃(py)₄] ( 1 ), LaCl₃(py)₄] · 0.5 py ( 2 · 0.5 py), and ErCl₃(py)₄] · 0.5 py ( 3 · 0.5 py) have been prepared from the diacetone‐alcohol complexes LnCl₃(DAA)₂] or directly from the metal trichlorides with excess pyridine to give colourless, only sparingly moisture sensitive crystals. They were characterized by IR spectroscopy and by crystal structure determinations. 1 : Space group Pbca, Z = 16, lattice dimensions at –80 °C: a = 1647.4(1), b = 1743.1(1), c = 3190.5(1) pm, R₁ = 0.031. 2 · 0,5 Py: Space group P2₁/n, Z = 4, lattice dimensions at –80 °C: a = 978.9(1), b = 1704.5(1), c = 1589.5(1) pm, β = 103.61(1)°, R₁ = 0.0281. 3 · 0,5 Py: Space group P2₁/n, Z = 4, lattice dimensions at –80 °C: a = 970.1(1), b = 1706.4(1), c = 1566.1(1) pm, β = 103.46(1)°, R₁ = 0.0232. All complexes realize monomeric molecular structures with the metal atom in a distorted pentagonal‐bipyramidal coordination. One of the chlorine atoms and the four pyridine molecules are in the equatorial plane.