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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 Entstehung: Anmerkungen: Beschreibung: AbstractDeprotonation 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 [YbI2(thf)4] and [EuI2(thf)4] in THF forming[Yb2(Ap*py)3I(thf)] and [Eu2(Ap*py)3I(thf)], respectively. The two YbII centers in [Yb2(Ap*py)3I(thf)] are in close proximity and chemically different. Thus, an f‐block‐element–f‐block‐element coupling pattern was observed. The low‐field 171Yb 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 171Yb isotope and was assigned as a doublet arising from 1J(171Yb, 171Yb) spin‐spin coupling with a magnitude of 76.1 Hz. The 151Eu Mössbauer spectrum of [Eu2(Ap*py)3I(thf)] recorded at 77 K shows an isomer shift (δ) of –11.9(1) mm/s with an experimental line width (Γ) 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 [Yb2(Ap*py)3I(thf)] with Ap*pyK leads to [Yb2(Ap*py)4(thf)2]. In the reactions of [Yb2(Ap*py)3I(thf)] with azidotrimethylsilane and sulfur the rearrangement products [Yb2(Ap*py)3I2] and [Yb2(Ap*py)3I3] were obtained, respectively. Treating [Yb2(Ap*py)3I(thf)] with NaN(SiMe3)2 afforded homoleptic “ate” complex Na2[Yb(Ap*py)4]. A mixed silylamide dipyridylamide complex was obtained in the reaction of NaYb[N(SiMe3)2]3 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)