Details

Autor(en) / Beteiligte

• Fedushkin, Igor L
• Lukoyanov, Anton N
• Baranov, Evgeny V

Titel

Lanthanum Complexes with a Diimine Ligand in Three Different Redox States

Ist Teil von

• Inorganic chemistry, 2018-04, Vol.57 (8), p.4301-4309

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• 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/I2 = 2/1) in tetrahydrofuran (thf) or dimethoxyethane (dme) affords lanthanum­(III) complexes of dpp-Bian dianion: deep blue [(dpp-Bian)2–­LaI­(thf)2]2 (1, 84%) was isolated by crystallization of the product from hexane, while deep green [(dpp-Bian)­LaI­(dme)2] (2, 93%) precipitated from the reaction mixture in the course of its synthesis. A treatment of complex 1 with 0.5 equiv of I2 in thf leads to the oxidation of the dpp-Bian dianion to the radical anion and results in the complex [(dpp-Bian)1–­LaI2(thf)3] (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)2–­La­(Cp*)­I]­[Na­(18-crown-6)­(thf)2] (4, 71%). In the absence of crown ether the alkali metal salt-free complex [(dpp-Bian)2–­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)4–­La­(thf)]­[K­(thf)3]}2 (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.