Tris(ethanol-κO)tris-(picrato-κO,O)lanthanum(III) tri-2-pyridylamine solvate

Acta Crystallogr Sect E Struct Rep Online. 2008 Jul 5;64(Pt 8):m984-5. doi: 10.1107/S1600536808019296.


The title compound, [La(C(6)H(2)N(3)O(7))(3)(C(2)H(6)O)(3)]·C(15)H(12)N(4), has two mol-ecular building blocks, namely the neutral mononuclear adduct of lanthanum picrate with ethanol [i.e. La(pic)(3):EtOH (1:3); La(pic)(3) = lanthanum picrate and EtOH = ethanol] and the oligodentate aromatic nitro-gen base tri-2-pyridylamine (tpa). The asymmetric unit contains two formula units. The compound was prepared during an investigation of the stereochemistry of lanthanoid picrate complexes with O-donor ligands. The metal-ligand adduct adopts a nine-coordinate tricapped trigonal-prismatic metal atom environment. The stereochemical arrangement of the ligands about the metal core is typical of a fac-isomer with stoichiometry M(bidentate)(3)(monodentate)(3). Face-to-face hydrogen bonds are found between the tpa mol-ecule and the ethanol ligands. One ethanol ligand is disordered over two positions, with site occupancy factors of ca 0.7 and 0.3. The oxygen atoms of a nitro group are also disordered over two positions; the site occupancy factors are ca 0.6 and 0.4.