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Medientyp: E-Artikel Titel: Bimetallic Complexes of Ytterbium and Europium Stabilized by Sterically Demanding Dipyridylamides Beteiligte: Dietel, Anna M.; Döring, Christian; Glatz, Germund; Butovskii, Mikhail V.; Tok, Oleg; Schappacher, Falko M.; Pöttgen, Rainer; Kempe, Rhett Erschienen: Wiley, 2009 Erschienen in: European Journal of Inorganic Chemistry, 2009 (2009) 8, Seite 1051-1059 Sprache: Englisch DOI: 10.1002/ejic.200801055 ISSN: 1434-1948; 1099-0682 Schlagwörter: Inorganic Chemistry Entstehung: Anmerkungen: Beschreibung: <jats:title>Abstract</jats:title><jats:p>Deprotonation of Ap*pyH {Ap*pyH = (6‐methylpyridin‐2‐yl)‐[6‐(2,4,6‐triisopropylphenyl)‐pyridin‐2‐yl]‐amine} using KH leads to Ap*pyK which undergoes a clean salt metathesis reaction with [YbI<jats:sub>2</jats:sub>(thf)<jats:sub>4</jats:sub>] and [EuI<jats:sub>2</jats:sub>(thf)<jats:sub>4</jats:sub>] in THF forming[Yb<jats:sub>2</jats:sub>(Ap*py)<jats:sub>3</jats:sub>I(thf)] and [Eu<jats:sub>2</jats:sub>(Ap*py)<jats:sub>3</jats:sub>I(thf)], respectively. The two Yb<jats:sup>II</jats:sup> centers in [Yb<jats:sub>2</jats:sub>(Ap*py)<jats:sub>3</jats:sub>I(thf)] are in close proximity and chemically different. Thus, an f‐block‐element–f‐block‐element coupling pattern was observed. The low‐field <jats:sup>171</jats:sup>Yb signal consists of a central singlet and two satellites with integral intensities of about 7 % each. This 14 % approximately corresponds to the natural abundance of the <jats:sup>171</jats:sup>Yb isotope and was assigned as a doublet arising from <jats:sup>1</jats:sup><jats:italic>J</jats:italic>(<jats:sup>171</jats:sup>Yb, <jats:sup>171</jats:sup>Yb) spin‐spin coupling with a magnitude of 76.1 Hz. The <jats:sup>151</jats:sup>Eu Mössbauer spectrum of [Eu<jats:sub>2</jats:sub>(Ap*py)<jats:sub>3</jats:sub>I(thf)] recorded at 77 K shows an isomer shift (<jats:italic>δ</jats:italic>) of –11.9(1) mm/s with an experimental line width (<jats:italic>Γ</jats:italic>) of 6.9(1) mm/s. This line width is extremely large and results from an overlap of the signals from both crystallographically independent europium sites. The reaction of [Yb<jats:sub>2</jats:sub>(Ap*py)<jats:sub>3</jats:sub>I(thf)] with Ap*pyK leads to [Yb<jats:sub>2</jats:sub>(Ap*py)<jats:sub>4</jats:sub>(thf)<jats:sub>2</jats:sub>]. In the reactions of [Yb<jats:sub>2</jats:sub>(Ap*py)<jats:sub>3</jats:sub>I(thf)] with azidotrimethylsilane and sulfur the rearrangement products [Yb<jats:sub>2</jats:sub>(Ap*py)<jats:sub>3</jats:sub>I<jats:sub>2</jats:sub>] and [Yb<jats:sub>2</jats:sub>(Ap*py)<jats:sub>3</jats:sub>I<jats:sub>3</jats:sub>] were obtained, respectively. Treating [Yb<jats:sub>2</jats:sub>(Ap*py)<jats:sub>3</jats:sub>I(thf)] with NaN(SiMe<jats:sub>3</jats:sub>)<jats:sub>2</jats:sub> afforded homoleptic “ate” complex Na<jats:sub>2</jats:sub>[Yb(Ap*py)<jats:sub>4</jats:sub>]. A mixed silylamide dipyridylamide complex was obtained in the reaction of NaYb[N(SiMe<jats:sub>3</jats:sub>)<jats:sub>2</jats:sub>]<jats:sub>3</jats:sub> with Ap*pyH. All complexes – three of which are paramagnetic – were characterized by X‐ray crystal structure analysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)</jats:p>