Lanthanum Complexes with a Diimine Ligand in Three Different Redox States.

Title Lanthanum Complexes with a Diimine Ligand in Three Different Redox States.
Authors I.L. Fedushkin; A.N. Lukoyanov; E.V. Baranov
Journal Inorg Chem
DOI 10.1021/acs.inorgchem.7b03112

The reduction of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-Bian) with an excess of La metal in the presence of iodine (dpp-Bian/I = 2/1) in tetrahydrofuran (thf) or dimethoxyethane (dme) affords lanthanum(III) complexes of dpp-Bian dianion: deep blue [(dpp-Bian)LaI(thf)] (1, 84%) was isolated by crystallization of the product from hexane, while deep green [(dpp-Bian)LaI(dme)] (2, 93%) precipitated from the reaction mixture in the course of its synthesis. A treatment of complex 1 with 0.5 equiv of I in thf leads to the oxidation of the dpp-Bian dianion to the radical anion and results in the complex [(dpp-Bian)LaI(thf)] (3). Addition of 18-crown-6 to the mixture of 1 and NaCp* (Cp* = 1,2,3,4,5-pentamethylcyclopentadienyl) in thf affords ionic complex [(dpp-Bian)La(Cp*)I][Na(18-crown-6)(thf)] (4, 71%). In the absence of crown ether the alkali metal salt-free complex [(dpp-Bian)LaCp*(thf)] (5, 67%) was isolated from toluene. Reduction of complex 1 with an excess of potassium produces lanthanum-potassium salt of the dpp-Bian tetra-anion {[(dpp-Bian)La(thf)][K(thf)]} (6, 68%). Diamagnetic compounds 1, 2, 4, 5, and 6 were characterized by NMR spectroscopy, while paramagnetic complex 3 was characterized by the electron spin resonance spectroscopy. Molecular structures of 2-6 were established by single-crystal X-ray analysis.

Citation I.L. Fedushkin; A.N. Lukoyanov; E.V. Baranov.Lanthanum Complexes with a Diimine Ligand in Three Different Redox States.. Inorg Chem. 2018;57(8):43014309. doi:10.1021/acs.inorgchem.7b03112

Related Elements


See more Lanthanum products. Lanthanum (atomic symbol: La, atomic number: 57) is a Block F, Group 3, Period 6 element with an atomic weight of 138.90547. Lanthanum Bohr ModelThe number of electrons in each of lanthanum's shells is [2, 8, 18, 18, 9, 2] and its electron configuration is [Xe] 5d1 6s2. The lanthanum atom has a radius of 187 pm and a Van der Waals radius of 240 pm. Lanthanum was first discovered by Carl Mosander in 1838. In its elemental form, lanthanum has a silvery white appearance.Elemental Lanthanum It is a soft, malleable, and ductile metal that oxidizes easily in air. Lanthanum is the first element in the rare earth or lanthanide series. It is the model for all the other trivalent rare earths and it is the second most abundant of the rare earths after cerium. Lanthanum is found in minerals such as monazite and bastnasite. The name lanthanum originates from the Greek word Lanthaneia, which means 'to lie hidden'.

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