Crystal structure of tris(1,1,1,2,2,3,3-heptafluoro-7,7-dimethyl-4,6-octanedionato) aquolutetium(III)—Lu(fod)₃. H₂O

Abstract

The crystal structure of Lu(fod)₃. H₂O has been solved by three-dimensional X-ray methods at room temperature. The space group isPĪ and the cell dimensions area = 16·392,b = 22·492,c = 13·366 Å, α = 91·83 °, β = 119·93 °, γ = 90·00 °. There are four formula-units per unit cell;D _m = 1·66,D _c = 1·667 g cm⁻³. Least-squares refinement of atomic and individual isotropic thermal parameters terminated withR = 0·128. This relatively highR factor is due to crystal decomposition, to the prohibitively large asymmetric unit which necessitated refinement in parts and also to the high vapour pressure of the compound and consequently large thermal vibrations in the structure. These factors caused large uncertainties especially in the positions of the atoms at the ends of the long side chains, but the more important geometry of the coordination polyhedra at the cores of the roughly spherical molecules have been firmly established. Except for orientation differences, the two crystallographically independent formula-units are very similar and both are dimerized through water molecules with hydrogen bonds across centres of symmetry. In each case the coordination of lutetium is seven-fold, with the geometry of a monocapped trigonal prism.