| Autor: |
Fedushkin IL; G.A. Razuvaev Institute of Organometallic Chemistry of the Russian Academy of Sciences , Tropinina Street 49, Nizhny Novgorod 603137, Russian Federation.; Koz'ma Minin Nizhny Novgorod State Pedagogical University , Ul'yanova Street 1, Nizhny Novgorod, 603002, Russian Federation., Yambulatov DS; G.A. Razuvaev Institute of Organometallic Chemistry of the Russian Academy of Sciences , Tropinina Street 49, Nizhny Novgorod 603137, Russian Federation., Skatova AA; G.A. Razuvaev Institute of Organometallic Chemistry of the Russian Academy of Sciences , Tropinina Street 49, Nizhny Novgorod 603137, Russian Federation., Baranov EV; G.A. Razuvaev Institute of Organometallic Chemistry of the Russian Academy of Sciences , Tropinina Street 49, Nizhny Novgorod 603137, Russian Federation., Demeshko S; Institut für Anorganische Chemie, Universität Göttingen , Tammannstrasse 4, 37077 Göttingen, Germany., Bogomyakov AS; International Tomography Center, Siberian Branch of the Russian Academy of Sciences , Institutskaya Street 3a, Novosibirsk 630090, Russian Federation., Ovcharenko VI; International Tomography Center, Siberian Branch of the Russian Academy of Sciences , Institutskaya Street 3a, Novosibirsk 630090, Russian Federation., Zueva EM; A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Centre of the Russian Academy of Sciences , Arbuzov Street 8, Kazan 420088, Russian Federation.; Kazan Federal University , Kremlyovskaya Street 18, Kazan 420008, Russian Federation. |
| Abstrakt: |
The reaction of (dpp-Bian)Eu II (dme) 2 (3) (dpp-Bian is dianion of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene; dme is 1,2-dimethoxyethane) with 2,2'-bipyridine (bipy) in toluene proceeds with replacement of the coordinated solvent molecules with neutral bipy ligands and affords europium(II) complex (dpp-Bian)Eu II (bipy) 2 (9). In contrast the reaction of related ytterbium complex (dpp-Bian)Yb II (dme) 2 (4) with bipy in dme proceeds with the electron transfer from the metal to bipy and results in (dpp-Bian)Yb III (bipy)(bipy - ̇) (10) - ytterbium(III) derivative containing both neutral and radical-anionic bipy ligands. Noteworthy, in both cases dianionic dpp-Bian ligands retain its reduction state. The ligand-centered redox-process occurs when complex 3 reacts with N,N'-bis[2,4,6-trimethylphenyl]-1,4-diaza-1,3-butadiene (mes-dad). The reaction product (dpp-Bian)Eu II (mes-dad)(dme) (11) consists of two different redox-active ligands both in the radical-anionic state. The reduction of 3,6-di-tert-butyl-4-(3,6-di-tert-butyl-2-ethoxyphenoxy)-2-ethoxycyclohexa-2,5-dienone (the dimer of 2-ethoxy-3,6-di-tert-butylphenoxy radical) with (dpp-Bian)Eu II (dme) 2 (3) caused oxidation of the dpp-Bian ligand to radical-anion to afford (dpp-Bian)(ArO)Eu II (dme) (ArO = OC 6 H 2 -3,6-tBu 2 -2-OEt) (12). The molecular structures of complexes 9-12 have been established by the single crystal X-ray analysis. The magnetic behavior of newly prepared compounds has been investigated by the SQUID technique in the range 2-310 K. The isotropic exchange model has been adopted to describe quantitatively the magnetic properties of the exchange-coupled europium(II) complexes (11 and 12). The best-fit isotropic exchange parameters are in good agreement with their density functional theory-computed counterparts. |
