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The crystal structure of tetraethylenglycoltrinitrato lanthanum(III): an example of undecacoordination

1982; Elsevier BV; Volume: 61; Linguagem: Inglês

10.1016/s0020-1693(00)89137-9

1873-3255

U. Casellato, G. Tomat, P. Di Bernardo, R. Graziani,

Crystal structures of chemical compounds

The title compound has been prepared by reacting La(NO3)3 with tetraethylenglycol. The structure was determined from counter-collected data and refined to R = 0.049 for 2310 reflections. The space group is P21/n, monoclinic, with cell dimensions a = 12.75(1), b = 16.84(1), c = 8.15(1) Å, β = 101.27(3)°, Dx = 2.01 g cm−3 for Z = 4. The pentadentate organic ligand wraps around the metal ion which is also bound to three chelate nitrato groups, thus achieving the rather uncommon undeca-coordination. Five La-O(nitrate) (mean 2.61 Å) compare well with the two LaO(alcohol) bond distances (mean 2.58 Å). One LaO (nitrate) (2.79 Å) and the three LaO(ether) bond distances (mean 2.70 Å) are significantly longer. Weak intra- and intermolecular hydrogen bonds are also present.