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3. Gradual solid-state redox-isomerism in the lanthanide series.

Author

Lukina, Daria A., Skatova, Alexandra A., Rumyantcev, Roman V., Demeshko, Serhiy V., Meyer, Franc, and Fedushkin, Igor L.

Subjects
*CHARGE exchange, *ACENAPHTHENE, *TAUTOMERISM, *RARE earth metals
Abstract

Oxidation of [(ArBIG-bian)2−Yb2+(dme)] (1) (ArBIG-bian = 1,2-bis[(2,6-dibenzhydryl-4-methylphenyl)imino]acenaphthene; dme = 1,2-dimethoxyethane) by 0.5 equivalent of Me2NC(S)S–S(S)CNMe2 in dme at ambient temperature affords a mixture of two products, [(ArBIG-bian)2−Yb3+{SC(S)NMe2}1−(dme)] and [(ArBIG-bian)1−Yb2+{SC(S)NMe2}1−(dme)], which represent two redox-isomers (2a and 2b, respectively). Their ratio in solution depends on the solvent as well as on the temperature. In the solid state, a decrease of temperature (350 → 100 K) caused an electron transfer from the Yb2+ ion to the ArBIG-bian radical-anion in isomer 2b to afford isomer 2a. Accordingly, the ratio of isomers 2a and 2b changes from 1 : 1 (350 K) to 3 : 1 (100 K). In contrast, in the dimer [(dme)(dpp-bian)1−Yb2+(μ-Cl)2Yb3+(dpp-bian)2−(dme)] (dpp-bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene), which is the sole example of a lanthanide complex that reveals solid-state redox-isomerism (valence tautomerism) reported so far, the electron transfer from the Yb2+ ion to the dpp-bian radical-anion takes place at around 150 K and is completed within a temperature interval of ca. 7 K. [ABSTRACT FROM AUTHOR]

Published
2024
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17. Magnesium and Calcium Complexes of ArBIG-bian and Their Reactivity towards CO2 (ArBIG-bian=1,2-bis[(2,6-dibenzhydryl-4-methylphenyl)imino]acenaphthene).

Author

Moskalev, Mikhail V., Skatova, Alexandra A., Razborov, Danila A., Bazanov, Andrey A., Bazyakina, Natalia L., Sokolov, Vladimir G., and Fedushkin, Igor L.

Subjects
*MAGNESIUM compounds, *ACENAPHTHENE, *MOLECULAR structure, *ELEMENTAL analysis, *NUCLEAR magnetic resonance spectroscopy, *MAGNESIUM diboride
Abstract

Reduction of 1,2-bis[(2,6-dibenzhydryl-4-methylphenyl)imino] acenaphthene (ArBIG-bian) with an excess of magnesium in tetrahydrofuran (thf) or with an excess of calcium in 1,2-dimethoxyethane (dme) and crystallization of the crude products from the reaction mixtures affords monomeric complexes [(ArBIG-bian)Mg(thf)2] (1) or [(ArBIG-bian)Ca(dme)2] (2), respectively. Hydrolysis of complex 1 affords metal-free diamine [ArBIGbianH2(thf)] (3). Complexes 1 and 2 readily react with CO2 to form the corresponding carbamates [(ArBIG-bian)(CO2)2Mg(thf)2] (4) and [(ArBIG-bian)(CO2)2Ca(dme)2] (5). Compounds 1-5 have been characterized by NMR and IR spectroscopy as well as elemental analysis. The molecular structures of 1, 2, 3, and 5 have been determined by the single crystal X-ray analysis. [ABSTRACT FROM AUTHOR]

Published
2021
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20. Alkali Metal Reduction of 1,2‐Bis[(2,6‐dibenzhydryl‐4‐methylphenyl)imino]acenaphthene (ArBIG‐bian) to Radical‐Anion.

Author

Moskalev, Mikhail V., Razborov, Danila A., Skatova, Alexandra A., Bazanov, Andrey A., and Fedushkin, Igor L.

Subjects
ACENAPHTHENE, ELECTRON paramagnetic resonance spectroscopy, ALKALI metals, BISMUTH, TETRAHYDROFURAN, DIMERIZATION
Abstract

Reduction of ArBIG‐bian (1, 1,2‐bis[(2,6‐dibenzhydryl‐4‐methylphenyl)imino]acenaphthene) with one molar equivalent of Li, Na or K in tetrahydrofuran (THF) affords corresponding radical‐anionic salts (ArBIG‐bian)M(THF) (M=Li, 2; Na, 3; K, 4). Compounds 2–4 were isolated in good yields and characterized by the elemental analysis, IR and ESR spectroscopy as well as the single‐crystal X‐Ray analysis. Bulky Ph2(H)C groups in ArBIG‐bian ligand prevent dimerization of complexes 2–4 and limit a number of coordinated THF molecules to one. In all three products a saturation of the alkali metal coordination sphere is achieved through an interaction with Ph rings of Ph2(H)C substituents. [ABSTRACT FROM AUTHOR]

Published
2021
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21. Low-coordinate Sm(II) and Yb(II) complexes derived from sterically-hindered 1,2-bis(imino)acenaphthene (ArBIG-bian).

Author

Lukina, Daria A., Skatova, Alexandra A., Sokolov, Vladimir G., Baranov, Evgenii V., Demeshko, Serhiy, Ketkov, Sergey Yu., and Fedushkin, Igor L.

Subjects
*MOLECULAR structure, *MAGNETIC moments, *CRYSTAL lattices, *MAGNETIC susceptibility, *NUCLEAR magnetic resonance spectroscopy, *CRYSTALLIZATION
Abstract

Reduction of ArBIG-bian (1, 1,2-bis[(2,6-dibenzhydryl-4-methylphenyl)imino]acenaphthene) with an excess of samarium in tetrahydrofuran (thf) and crystallization of the crude product from a thf/toluene mixture affords [(ArBIG-bian)Sm]·C7H8 (2a), which is free of the coordinating solvent. The use of 1,2-dimethoxyethane (dme) as the reaction medium resulted in the same product, [(ArBIG-bian)Sm]·C4H10O2 (2b), which differs from 2a only in the crystal lattice solvent. Reduction of 1 with an excess of ytterbium in dme gives compound [(ArBIG-bian)Yb(dme)]·2.5C7H8 (3), containing a coordinated dme molecule. All three products consist of dianionic ArBIG-bian ligands whose bulky 2,6-(Ph2CH)2-4-Me–C6H2 groups shield effectively the metal atoms. The newly prepared compounds 2a, 2b and 3 were characterized by 1H NMR and IR spectroscopy. The molecular structures of complexes 2a, 2b and 3 have been established by single crystal X-ray analysis. The intramolecular interactions were analysed on the basis of DFT calculations. The temperature dependence of the magnetic susceptibility of 2b and 3 in the region of 2–300 K was studied. The magnetic moments of complex 2b correspond to divalent samarium. [ABSTRACT FROM AUTHOR]

Published
2020
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26. Mixed Lithium–Aluminum Hydrides Bearing Ar-Bian Ligands: Reactivity Toward Heteroallenes

Author

Koptseva, Tatyana S., Bazanov, Andrey A., Skatova, Alexandra A., Moskalev, Mikhail V., Baranov, Evgeny V., and Fedushkin, Igor L.

Abstract

The reactivity of [(dpp-Bian)Al(H)2Li(THF)3] (1) (dpp-Bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) and [(ArBIG-Bian)Al(H)2Li(THF)4] (2) (ArBIG-Bian = 1,2-bis[(2,6-dibenzhydryl-4-methylphenyl)imino]acenaphthene) toward isocyanates and carbodiimides has been investigated. A treatment of 1with tert-buthylisocyanate affords the formimidate derivative [(dpp-Bian)Al(μ2-OC(H)NtBu)2Li(THF)] (3). The related [(ArBIG-Bian)Al(μ2-OC(H)NCy)2Li(THF)] (4) and [(ArBIG-Bian)Al((μ-OC(H)NPh)Li(THF)3)(OC(H)NPh)] (5) have been obtained by reacting of 2with cyclohexyl and phenylisocyanates, respectively. Cyclohexylcarbodiimide reacts with 1and 2to give the corresponding amidinate derivatives [(dpp-Bian)Al(CyNC(H)NCy)(μ-CyNC(H)NCy)Li(THF)2] (6) and [(ArBIG-Bian)Al(CyNC(H)NCy)][Li(DME)3] (7). Complexes 3-7were characterized by IR and NMR spectroscopy. The molecular structures of compounds 3-7were determined by single-crystal X-ray analysis. Both 1and 2serve well as catalysts in the hydroboration of isocyanates and carbodiimides by pinacolborane (HBpin).

Published
2024
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27. Ytterbium and Europium Complexes of Redox-Active Ligands: Searching for Redox Isomerism

Author

Fedushkin, Igor L., Yambulatov, Dmitriy S., Skatova, Alexandra A., Baranov, Evgeny V., Demeshko, Serhiy, Bogomyakov, Artem S., Ovcharenko, Victor I., and Zueva, Ekaterina M.

Abstract

The reaction of (dpp-Bian)EuII(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)EuII(bipy)2(9). In contrast the reaction of related ytterbium complex (dpp-Bian)YbII(dme)2(4) with bipy in dme proceeds with the electron transfer from the metal to bipy and results in (dpp-Bian)YbIII(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 3reacts with N,N′-bis[2,4,6-trimethylphenyl]-1,4-diaza-1,3-butadiene (mes-dad). The reaction product (dpp-Bian)EuII(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)EuII(dme)2(3) caused oxidation of the dpp-Bian ligand to radical-anion to afford (dpp-Bian)(ArO)EuII(dme) (ArO = OC6H2-3,6-tBu2-2-OEt) (12). The molecular structures of complexes 9–12have 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 (11and 12). The best-fit isotropic exchange parameters are in good agreement with their density functional theory-computed counterparts.

Published
2024
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28. Ligand “Brackets” for Ga–Ga Bond

Author

Fedushkin, Igor L., primary, Skatova, Alexandra A., additional, Dodonov, Vladimir A., additional, Yang, Xiao-Juan, additional, Chudakova, Valentina A., additional, Piskunov, Alexander V., additional, Demeshko, Serhiy, additional, and Baranov, Evgeny V., additional

Published
2016
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34. 1,2-Bis(imino)acenaphthene complexes of molybdenum and nickel

Author

Fedushkin, Igor L., primary, Skatova, Alexandra A., additional, Lukoyanov, Anton N., additional, Khvoinova, Nalalie M., additional, Piskunov, Alexander V., additional, Nikipelov, Alexander S., additional, Fukin, Georgy K., additional, Lysenko, Konstantin A., additional, Irran, Elisabeth, additional, and Schumann, Herbert, additional

Published
2009
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40. Monomeric Magnesium and Calcium Complexes containing the Rigid, Dianionic 1, 2-Bis[(2, 5-di-tert-butylphenyl)imino]acenaphthene (dtb-BIAN) and 1, 2-Bis[(2-biphenyl)imino]acenaphthene (bph-BIAN) Ligands

Author

Fedushkin, Igor L., primary, Chudakova, Valentina A., additional, Skatova, Alexandra A., additional, Khvoinova, Natalie M., additional, Kurskii, Yuri A., additional, Glukhova, Tatyana A., additional, Fukin, Georgy K., additional, Dechert, Sebastian, additional, Hummert, Markus, additional, and Schumann, Herbert, additional

Published
2004
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48. Reduction of Disulfides with MagnesiumII and GalliumII Complexes of a RedoxActive Diimine Ligand

Author

Fedushkin, Igor L., Nikipelov, Alexander S., Skatova, Alexandra A., Maslova, Olga V., Lukoyanov, Anton N., Fukin, Georgy K., and Cherkasov, Anton V.

Abstract

The reactions of dppbianMgthf31 {dppbian = 1,2bis[2,6diisopropylphenylimino]acenaphthene} with 0.5 molar equivalents of RS–SR R = Bz, sBu, CSNMe2 occur with a cleavage of the S–S bond to afford monosulfide complexes dppbianMgSBzdme 2, dppbianMg[SsBu]dme 3, and dppbianMg[SCSNMe2]thf 4. Compounds 2, 3, and 4are paramagnetic due to the presence of dppbian radicalanions that are formed in the course of oneelectron transfer from the dppbian dianion in 1to the sulfurcontaining substrate. Reduction of BzS–SBz with gallane dppbianGa–Gadppbian 5 gives a mononuclear GaIIIcomplex with the dppbian radicalanion, dppbianGaSBz26. The reaction of 5with RS–SR R = CSNMe2 proceeds with a cleavage of the S–S and Ga–Ga bonds and affords dppbianGa[SCSNMe2] 7, in which the dppbian ligand retains its dianionic state. Complexes 2, 3, 4, and 6have been characterized by ESR and IR spectroscopy, and complex 7has been studied by 1H MNR spectroscopy. The molecular structures of 2–4, 6, and 7have been determined by Xray crystallography. © WileyVCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009

Published
2009
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49. Reduction of Benzophenone and 9(10H)-Anthracenone with the Magnesium Complex [(2,6-iPr<INF>2</INF>C<INF>6</INF>H<INF>3</INF>-bian)Mg(thf)<INF>3</INF>]

Author

Fedushkin, Igor L., Skatova, Alexandra A., Cherkasov, Vladimir K., Chudakova, Valentina A., Dechert, Sebastian, Hummert, Markus, and Schumann, Herbert

Abstract

The reduction of benzophenone with the magnesium complex [(2,6-iPr2C6H3-bian)Mg(thf)3] (1), containing the 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene dianion, affords the pinacolato complex [(2,6-iPr2C6H3-bian)Mg(thf)]2[μ-O2C2Ph4]·(C6H6)4 (2). The reaction of 1 with 9(10H)-anthracenone yields the 9-anthracenolato complex [(2,6-iPr2C6H3-bian)Mg(OC14H9)(thf)2] (3). Complexes 2 and 3 were characterized by elemental analyses, UV/Vis, IR, and ESR spectroscopy, as well as by single crystal X-ray diffraction. Complex 2 dissociates in solution with splitting of the bridging pinacolato unit, forming the biradical diimino/ketyl complex [(2,6-iPr2C6H3-bian)Mg(thf)(OCPh2)].

Published
2003
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50. Oxidative Addition of Phenylacetylene through C&bond;H Bond Cleavage To Form the Mg<SUP><SC>II</SC></SUP>–dpp-bian Complex: Molecular Structure of [Mg{dpp-bian(H)}(C&tbond;CPh)(thf)<INF>2</INF>] and Its Diphenylketone Insertion Product [Mg(dpp-bian)<SUP>.</SUP><SUP>−</SUP>{OC(Ph<INF>2</INF>)C&tbond;CPh}(thf)] <FNR HREF="nss"></FNR> <FN ID="nss"> This work was supported by the Russian Foundation for Basic Research (Grant No. 03-03-32246), dpp-bian=bis[N-(2,6-diisopropylphenyl)imino]acenaphthene. The authors thank Dr. Yu. A. Kurskii for recording the NMR spectra. </FN>

Author

Fedushkin, Igor L., Khvoinova, Natalie M., Skatova, Alexandra A., and Fukin, Georgy K.

Abstract

No Abstract

Published
2003
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